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April 17. 1972 Ur. It. Morgan Hoover, Secretary Food, Drug, and Cosmetic Chemicals Coanlttee Manufacturing Chemists Association 1825 Connecticut Avenue, H.W. Washington, D.C. 20009 Be: IUPAC Draft Specs for Dispersion Solvents Used in Food Dear Morgan: Reference your letter of March 29, Allied Chemical Is not a prime producer of any of subject solvents, but the writer would suggest that some attempt be made to set standards as uniform as possible throughout the world. To this end, X would recommend that any new set of specifications such as those being prepared for IUPAC fully recognise the existence of prior standards. It is questioned whether IUPAC needs to establish speci fications if specifications from recognized sources already exist. Thus, specifications for food quality propylene glycol have already been set by tbs Joint FAO/WHD Expert Committee os Food Additives (Seventh Bepert, 1964) end by Food Chemical Codex. These two specifications tor propylons glycol are very similar and, since the Expert Committee report pre-dates the Oodsx specifications, would guess that the letter was lifted substan tially unchanged. There are minor variations such as "residue on ignition" in tin Codex specifications and a stricter heavy metals test. Xt is motetfthat Dr. Howard's draft includes specifications for sulfate and chloride, probably derived from U.S.P. specifi cations Jfer propylene glycol. Since an "ash" or "residue n ignition" test limits these impurities sad they are not harmful in food in amounts likely to be present, the writer can see no adequate reason for these specifications. On tbs other band, it is necessary that arsenic and heavy metals be limited la food chemicals, even though the likelihood of their being present is remote. The need for refractive index specifications Is questioned if other means of identification are given as in FAO/WBO and Codex specifications. ASI 00003092 Mr. M. Mams Boever .2* April 17, 1972 7lo the writer's kaotlttfgt, tka only other food otealeal on Dr. Banrd* list for which a Monograph has boos written by a public organization is that for glycerol in Pood Chosicals Codes. If this is, in fact, true. Dr. Howard is netting a precedent for food additive specifications for the other chosicals listed. In this regard, the writer thinks it pre ferable to follow the pattern la 7A0/WBD or Pood Chosicals Codes, l.e. description. Identification and specification*, the latter covering assay, physical property Units, limits for anticipated impurities and Units for common toxic laments (arsenic, lead, other heavy metals) l.e. the minimum of specifications which will reasonably guarantee healthfulness. Unfortunately, I do not have the time to investigate the proposed specifications and methods mere thoroughly, but do think that international uniformity should be as objection* Tory truly yours. V. A. Knapp Consultant-Toxicology WAK:pb ce: Mr. T. V. Bansvan X. I. dopant do Measure h Company 1007 Market Street Wilmington, Delaware 19908 -wy ASI 00003093 p*1*: .< Ui MANUFACTURING CHEMISTS ASSOCIATION 1872 A CENTURY OF SERVICE 1972 182b CONNECTICUT AVENUE, N.W, WASHINGTON, D. C. 20009 (202) 483-6126 March 29, 1972 TOi FOOD, DRUG, AND COSMETIC CHEMICALS COMMITTEE Subject: IUPAC Draft Specs for Dispersion Solvents Used in Food Gentlemen: Dr. Hartley Howard, Technical Director of Borden Inc., has been delegated to solicit comments on the attached pro posed specifications from U. S. industry. Accordingly he has requested the assistance of MCA, as well as GMA and FEMA. Please let me have any comments you may have on these by May 10, so that they may be forwarded to Dr. Howard in time to be received by May 15, the date he needs them. Thank you. Sincerely yours. M. M. Hoover, Secretary Food, Drug, and Cosmetic Chemicals Committee MMHjgr Attachment Distribution "B" Food Additives Contacts in MCA Member Companies At AS I 00003094 COPIED BY MCA UiTSRPA'P 10I7AL URICR OP PUPS ADU) APPLIED CHEMISTRY APPLIED CHEMISTRY DIVISION POOD SHOTICH DRAFT 5? SC IPj CAT ICRS FOR SOME 7 DISPERSION SOLVENTS USED IJi FOOD I I f i ii i i 8 Food Additives Commission Fob. 1972 ASI 00003095 COIiTMETS 1 Preamble 2 . Specifications 2.1 Ethanol 2.2 Propan-2-ol 2.3 Glycerol 2.4 Glycerol monoacetate 2.^ Glycerol diacetato 2.6 Glycerol triacetate 2.7 Propan~l,2-diol 3 3-1 3.2 3.3 3-4 3-5 3.6 3.7 3.8 3.9 3.10 3*11 3.12 3.13 3-14 3.15 3.16 3-17 3.18 3.19 3.20 3.21 3.22 Methods of analysis to be used in conduction v/ith IUPAC specification The measurement of the relative density of solvents The determination of non-volatile residues in ethanol and propan-2-ol The determination of free acidity in ethanol, propan-2-ol, glycerol rnono~,di and tri-acetates and propan-1,2~diol The detection of methanol in ethanol The determination of aldehydes and hetonos in ethanol and propan-2-ol The detection of fusel oil in ethanol and propan-2-ol Pujiwara test for the detection of organochlorine contaminants in ethanol and propan-2-ol The determination of the distillation range of propan-2-ol and propan-1,2-diol The determination of v.atcr in ethanol, propa.n-2-ol and glycerol triacetate and propan-1,2-diol The detection of free acid in glycerol The delermination of calfat ad ash The detection of copper in glycerol The detection of iron in glycerol The detection of chloride in glycerol The determination of fatty acids and esters in glycerol The detection of acrolein, in glycerol The measurement of refractive index The determination of the ash content of glycerol mono, di and tri-- acetales, and propan 1,2-diol The determination of sulphate in glycerol mono and diacetates The determination of chloride in glycerol mono and diacotates The determination of the ester content of glycerol di-and 1 '6- .cet at The detection of v;at cr and glycerol in glyccro?. diacetate ASI 00003096 CRAFT SPECIFICATIONS FOR SOME 8 DISPERSION 'SOLVENTS USED I!T FOOD 1. Preamble In 1970 the Food Additives end Contaminants Commission of the Food Section of XuPAC drew up minimum specifications as for 7 extraction solvents i;sed in Food Processing. In the course of this work specifications were obtained for many other solvents and it'was thought worthwniie to extend the study^to dispersion solvents and in particular, ethanol, pronan-2-ol, glycerol, glycerol aonacetate, glycerol diacctate, glycerol triacetate, propan-1,2-diol1' and butan~l,2-diol. 2. Minimum specifications In compliancewith the general recommendations of the FAO/WHO no solvent for use in food should be used which contains more than 0.001$ of heavy metal expressed as lead and not more than 0.0003$ arsenic, The limiting quantities are expressed as $ w/v throughout except where indicated. All temperatures axe in degrees centigrade. 2.1 Ethanol Assay, not less than Relative Density 20/20 Residue at 100,' not more than -Free Acidity (as acetic acid), not more than Methanol ' Aldehydes and Ketones (as acetone), not more than Coloration of residue with sulfuric acid (fusel oil) Fujiwara Test 95$ v/v 0.812-0.814 0.002>S 0.00p$ Passes Test 0.02$ Passes Test Negative Method 1 2 3 4 .5 6 7 Not e Other grades with hi gher water contents can be used, depending on the t echnolcgi cal require;::; tits; the specifications for these should be cl3 above with suitable adjus tment for any extra water present 2.2 Prewar--2--o1 Assay, not lose, then Relative Density IG/rc/" Distillation range, ICO;"' 'Rawer, not irer0 an n Residue r,t KC", net sore iR?e I!i"--* r.oR-rr -.esc') nee ro AldrRydan; . .I'T-1 (.as ae;r;.c no) l o l as re lean w i. o n. t u 1, u ^ ,i 0 a a i;; Pujiwura v.'s: 99->5$ v/v 0.75 - 0.783 81.o - 83.0 0. _i/ j 0.002$ po Method 1 8 3 5 6 7 ASI 00003 2.3 Glyoorol Assay, not less than Specific Gravity at 155i not less than Acidity Sulfated ash, not more than 99-C$ 1.2627 Passes test 0.01$ Method 1 10 11 Iron, not more than 0.5ppra Chloride > Passes test Patty acids and esters, not ecruivalent to more than 0.020$ as NagO Acrolein Passes test 13 14 15 16 Mote; Other grader, with higher water contents con he used, depending on the technological requirements, the specifications for these should he as above with suitable adjustment for any extra water present. 2.4 Glycerol monoacetata Boiling Point at 165mm Hg Relative Density, 2u$20o Refractive Index, n^O0 Ash, not more than Acidity (as acetic acid), not more than Chloride, (eg Cl) not more than Sulfate, (&3.CO) not r?re than I580 1.206 1.452 0.02$ 0.3$ 0.05$ as Cl 0.05$ as SO^ 8 17 18 3 14 19 2*5 Glycerol discstate Refractive Index ;iTi 200 Relative Pencil;/ a'A^xO0/20 Ash, not more than Ester content (as glycerol diacetate) Water and glycerol Sulfate, as ( SO. ) not more than Chlorides, ( as Cl ) not more tnon Acidity (as acetic acid), not more than 1.439 1.180 - 1.195 0.02$ &5 - 95$ w/w Passes test 0.05$ as SO4 0.05$ as Cl 0.3$ 17 1 18 21 22 19 20 3 ASI 00003098 urol trir-c-ai cie Relative Density 20/20 Refractive Index rtf00 V.'atcr, not more than Ash, not :.ore th-u Vote,], ccidiiy (as acetic acid), not more than Ector Content (ax OR. CCO). C. Iir j a nJ I.156 - 1.166 1.430 -- 1*434 0.2$ v/u 0,02$ u/w 0.05-5 98 - 100$ 1 17 9 18 *> J 2 2*7 Pro-nan-l * 2-dj ol Distillation Range, 100/ , Relative Density 20/20 Distillation range 9^1 v/v Refractive Index, n_/0 Ash, not more than Acidity (as acetic acid), not more than Sulfate as SO,,, not more than Chloride as Cl, not more than 185 - 189 1.038 - 1.040 185 - 1890 1.431 - 1.433 0.003/ 0.00355 . /,0 001 . /0 001 Kethod 1 8 17 18 3 19 20 ASI 00003099 \ :k% 7 3.I, The dotorniration of specific .gravity 'Of solvent For the purposes of "this method the following definition applies* The specific gravity at 2G/2GCin air of the glycerol is the ratio of the weight in air of a given volume of the glycerol at 209Cto that of the same volume of water at that temperature the weighing being made with weights adjusted to balance brass weights in air. 1. Apparatus: Density bottle, not less than 25^1 capacity, complying with B.S. 733 o* Pycnometer of similar capacity. 2. Procedure; Calibrate the specific gravity bottle or pycnometer as follows: Weigh the clean dry bottle or pycnometer, then fill it with cooled distilled water at about 10C and maintain it in a bath of water at 20C until it reaches that temperature. If a bottle is used, insert the stopper in such a way that the capillary is completely filled with water, and then maintain the filled bottle at 20C until no further alteration in volume occurs. Wipe the stopper. If a pycnometer is used, adjust the volume of liquid to the fixed mark. Remove the bottle or pycnometer from the bath, dry the outside allow to stand in a tared dish for a short time .aid weigh. Empty and dry the bottle or pycnometer. Fill it with the sample previously cooled to about 5C below the temperature of 20C, making sure no air bubbles are present. Maintain the bottle or pycnometer in a bath adjusted to 20C until it has reached that temperature. If a bottle is used, insert the stopper in such a way that the capillary is completely filled with glycerol and then maintain at 20C until no further alteration in volume occurs. Wipe the stopper. If a pyqnometer is used, adjust the volume to the fixed mark. Remove the apparatus from the oath, dry the outside, allow to stand for a short time in the tared dish and. weigh. Make all weighings in air with weights adjusted to balance brass weights in air. j i | , 1 , i j 3, Calculations and results ,, j Specific gravity of the solvent at 20/20C in air V.'i V`!2 where Wi = weight, in grammes,of glycerol obtained in the test and W2 = weight, in grammes, of water obtained in the calibration test. 4. Reference British Standard Specification 2621-5* 194* ASI 00003100 KSTHOD 2 ' 3*2. The determination of non-volatile residues in ethanol and. pronrn-2-ol '1 ' Principle of method; Evaporation to dryness. 2 Apparatus: A weighed basin of platinum, silica or boro-silicatev glasg; a boiling water bath; an oven at a temperature . 100i 2C; a desiccator; a balance, < ' 3 Procedure; Evaporate 100 ml of the sample to dryness in a weighed basin on a boiling water bath. Dry the residug Jor 30 minutes in an oven at a temperature of 100i 2 C. ; ` Cool in a desiccator and weigh. - 4 Calculations and results: Residue on evaporation (weighed in grams) represents per cent by weight per volume. 5 Reference; British Standard Specification 5091 1964. . ' ; ASI 00003101 it f K5TII0P 3 3.3 The determination of the acidity of ethanol, nropan-2-ol and '. acetone .' . . , 1 ' Principle of method: Titration-,against standard base.'.' .. 2 Annarn tus; Microburet to,: 500'nil conical flask. 3-. Koagents; The reagents used shall be of a recognised analytical . reagent quality. Distilled water, or water of at * ; * 1 least''.equal purity, shall be used throughout.;. . (&) Sodium' hydroxide 6.IN solution - ' - . ( (b) Pheno'lr.hthalein indicator. .Dissolve 0*5g.of ... phenolphthalein in 100 ml ethanol (55?^) find ' ' ` make faintly pink by the addition of dilute \ '; . . . sodium hydroxide solution.-v . : ' Procedure; Place 100 ml. of -water and a few clean antihumping ; .' - granules into a 500 ml conical flask of boro-silicate ! glass and boil for 5- minutes to eliminate carbon . 'dioxide.. Cool slightly, and add 100 ml of the sample. ... i ' 'V Boil gently for. a further 5 minutes. At the end of, ' . ' .. this period close.the neck of the flask with a stopper . ' - . " ' 1 carrying a soda-lime tube and allow to cool, non cold-- : ; ' ..remove the stopper, add 0.5 ml of the phenolphthalcin . . i. indicator and titrate with the-sodium hydroxide solution ' 1 ... using a microburette'. ' ` ' 1 v ' . . -**'' . ' : * 5 Calculation and results; The acidity, calculated as- acetic acid, ! ' =6x 1000 c/> w/\ where T-= volume, in ml., of Q.1N sodium hydroxido ' solution used, ,- # 6 . Deference;' British Standard Spocification 509; 1964* v ASI 00003102 ; KWVJLA ' : 3*4. ?ho detection of methanol in ethanol1, ` - .i-' /'V i ' 1 Principle of method. Oxidation of methanol by permanganate followed by reaction with .fuchsin bisulfite solution ' ` v-` 2 ' Reagents:. " Potassium normnnmanate ar.d -phosphoric acid solution; . . dissolve 3g of potassium permanganate in a mixture of i:': :V'vlv15 ml phosphoric acid (c15>j) and 70 ml of water; add `Vi;: sufficient water to produce 100 ml. ;; ;Y, Oxalic acid and sulfuric acid solution: a 5r> w/v . ' vg:;,-'-h/.;'. solution of oxalic acid in a cooled mixture of equal . 'V.dw/'hV-'VVV--- volumes of sulfuric acid -.Fuchsin bisulfite solution' and water. dissolver lg of basic .: magenta in 600 ml of water and cool in ice:' .add 20g of sodium sulphite dissolved in 100 ml of water, cool . in ice and add', slowly .and with constant stirring, "10 ml of S^yarochloric acid; dilute to 1000 ml. Xf V/ .. . ; the..solution is turbid it is filtered and if brown ; v..sufficient decolorising charcoal is added to render ; it colourless and it is then filtered immediately. V ' ..`Store protected from light. 5 "Procedure; Dilute 0.5 ml with water to 5 ml, add'2.0 ml of ` ...... potassium permanganate and phosphoric acid solution, .'7/:'Vallow to stand for ten minutes and add 2.0 ml of V;-.; oxalic acid and sulfuric acid solution; to tho ' colourless solution add 5 ml of .fuchsin bisulfite ... ... '..-. solution allow to stand at a temperature between f: " 15Cand p06 and examine after 30 minutes. . Xo odour . . ` -v" should be produced. ' , " /'.- ' 4 . Deference: British Pharmacopoeia 1968 p. 24. / V. ;- ' '://. ; V-Vk T.'-v:W'.'.'"-vy;1 ;A ; **. ,, * ` `i ASX 00003103 : ,r- . K3TK0D 5 35 The determination of aldehydes and ketones in ethanol and props.n-2-ol 1 Principle of method: Hydrochloric acid is liberated by the reaction between hydroxylanihe * chloride arid any aldehyde or ketone. The liberated acid is titrated with standard base. i 2 Ree/rents; Hvdrcrv'lanine chloride solution Dissolve lg of hydro:--yj.amine chloride in 50 rol water, add 50 mi ethanol (95^ v/v), and 1 ml bromophenol blue solution followed by 0.1 IT sodium hydroxide until the solution becomes green. 0.1 !T Sodjrr;i hvdroxi do solution Broinonliei'ioi blue solution: Warm O.lg of bromophenol blue with 3-0 ml of 6.05 IT sodium hydroxide and 5 ml of ethanol (90/i v/v) after solution is effected, add sufficient ethanol (20/) to give a total volume of 280 ml, 3 procedure; Heat-ICO ml of hydroxylaraine chloride solution in a loosely stoppered flask^'m a water-bath for 30 minutes, cool, and, if necessary, add sufficient 0.1 IT sodium hydroxide to restore the green colour. To 50 ml of this solution add 10 ml of water and 10 ml of the sample and heat on a water bath for ten minutes in a loosely stoppered flask. Cool, transfer to a Kessler cylinder and titrate with 0.1 IT sodium hydroxide until the colour matches that of the remainder of the hyd.roxylai.iine chloride solution contained in a similar cylinder, both solutions being viewed down the axis of the cylinder. 4 Calculations and results: Aldehydes and ketones, calculated as acetone ^ v/v - 0.00928T where T = volume in ml of 0.1 IT sodium hydroxide used. 5 Reference: British Pharmacopoeia 1968 p.24. ASI 00003104 t* \jt ro 3.6. -The detection of-fusel oil in ethanol and pronan-2-ol 1 Principle of method; Reaction of concentrated sulfuric acid and fuoel oil ........ to give a brown colour. ' ^ Apparatus: . porcelain dish. 4 ' : : Reagents; -'Concentrated sulfuric'acid. ' ' : Procedure; Allow 25 nl of ethanol or propan-2-ol to evaporate , - spontaneously in a porcelain dish, protected from ; _ dusif,-until-the surface on the dish is barely moist;, .. ; ' add 1 nl of sulfuric'acid. . ho red or brown colour ' should "be produced. v -- ,L ; . 5 Reference;' British'pharmacopoeia' 1963 p.24. ' ' . ' , ", KRTHOD 7 ' ' V 3 7 7u.jiwnra test for the dethet; or. c^ rr"--h~1o -er.-yte contaminants 1 -Principle of method: Reaction of certain polyhalogonatod oompounds ' , containing tho group CZ-,. and CIKp such as .,- ' `trichloroethylene with pyridine-sodium hydroxide to give a pink or red colour with heat. : 2. Apparatus; Constant temperature prater bath 7C^C, reaction cylinders (Glass stoppered pyrex 25 nl cylinders). ; Reagents; `Pyridine and nedirn hydroxide sointj.on To 40 mi distilled add 0.A8 nl l??i NaOII. ; Add 100 nl colourless 'pyridine, obtained by distilling technical grade over K0;I. . Do pot store for more than , 4 days. :: Procedure; Take 5 nl of the solvent, add 10 ml Fujiwara reagent, stopper ana nix. Remove stopper, place in constant. .. temperature bath at 70 C for exactly 15 minutes, maintaining water level above levels in cylinder. After 15 minutes remove cylinder and placo in water ' ` bath-at room temperature for 5 minutes. Add distilled Hj,0 to make 16 nl, stopper and nix. Prepare a control using 5 nl distilled water. There should not be a more intense colour in the test than .in tho control. 5 Remarks: 6 ~^Q'CC''?r*v*Cr* 'V Not all polyhaloger.ated compounds react. Pcigl Spot /Tests in Organic Analysis. - ; I1 . i ASI 00003105 3 8. The determination of T, k ")^OTv j.Oi rnn^o of prornr:-?~ol-. 1 prime?, nle of method : A 100 ml sample of the solvent is fractionally tiliCc Vi-(,G C oiling and tho dry points recorded. *A ppara'tus :' Distillation flaskQ 100 si. Thermometer 0-105 0. . ' , . I. .' ' . Condenser. Draught screen and asbestos board. 3 Procedure; Assemble tho rpo described in 3S 658. Measure 100 ml o* oa*.ipj,o vO e*o amsoxllntron xlas.e xrom a graduated measuring cylinder and add a granules. Place the l ^1" c-v thermometer and a suitable roceivor n.n position ana ensure tnat tne condenser nas a steady supply of water. Adjust the rate of heating so that the first drop of distillate falls' from the end of the condenser in 5 to 10 minutes, head the {.Cmper<\ \.-\* re a. w Lii@ jL^rs c crop xaj-j+G xrom oliO 0i0.<. v#0aiCfcC..lijO(.^aCL iTuOO.i as tho obseiTved initial boiling point. Further adjust tho rate of heating so that the distillato is ool-^eCt-cd a irne ra i/ti ox 5 m.L per hixuXifOc . neaG. one temperature indicated at the ins octT!t tho last drop of liquid evaporates iron the lowest point in the distillation' flask and record as tho observed dry point. Disregard any liquid on the side of the * 4 Interpretation of results: The initial boiling point at 760 an must not ... be below that required and the dry point at 760 mm prossure . ' must not be above that specified. 5 Perarks; ,1. If the thermometer gives incorrect readings at the observed initial boiling point or observed dry point, ' 1 correct the readings by' subtracting the amount of the error. ; -'2.' Road tho barometer and apply tho corrections as described ' - ' ', in BS 658. V 3. Vhcn.the corrected barometric pressure deviates from 760 mm j ' ; . v ' fig apply further corrections td tho osserved temperatures ' '' by subtracting ^ f ` " 0.033C for `' propan-2-ol for each millimetre above 760 mm or adding r.- , _ 0.0p3C for propan-2-ol "j for each millimetre below 760 mm. . -;;: j 6 Reference: ' British Standard Specifications 658, 1555 509 * available tn e . ' * rds t.L J^ J. ^ A w ' L. LX aouso..' COm TA><-AJh'.v D t'A U f XjO;**a)** f (tu j, f 1I l! i tf .i r: ASI 00003106 f K-:t7:o.9 9 . 5.9* Th r\ r ~ / *mo TT - ' cl crj.ic] rro^n-9-^7 . ciol Vat or determination by the Karl Pitcher method in based upon ' the fact that water reacts with iodine ar.d sulfui^dioxidc; stoichicmatrically in the presence of methanol ar.d pyridine as shown,in the following formula H,:o0 +'i,`+ S0,, + 3GWT d 1C. d Jp -- 2{c[.h_:;+h)i" '+ c^iyr.so. 1 5 5" 55 :rH.i7*RO. + CJLOi: ----- (c, ?V"+F) 0 r,c,,0 CH., 55 3 JJ 23 Apparatus: Generally, the apparatus comprises two automatic burettes, a titration flask and a stirrer, if necessary, an electrometric dcvico is used for the end-point doteruinavion. As the Karl Fischer reagent is extremely hygroscopic, t`no apparatus should he closed tightly to protect from atmospheric moisture. Desiccants such as silica gel or calcium chloride granules 'are used for protecting from moisture. Her.rents: h . . Noth-, nod for Yr.v.1 Fl.-cVr Method; rfo' 1,0C0 ml of methanol, add 5 C of. magnesium powder a:m heat tno mirxture in a flask connected with a reflux condenser, at the tor, of which a calc: urn chloride tube is attached. If accessary, add 0.?g of mercuric chloride to accelerate the reaction. Vfnen the generation of [j C, 3 } i LAS s to pp ad, dis til me th a no1 while protecting from moisture. 'Ike water content of methanol must not exceed 0.5 mg per ml. Store with protection from moisture. Pyridine fo1" Far] sc! f'r rotk/jj; To pyridine, add potassium hydroxide or barium oxide, sioppor lighiiy and allow to stand for a few days. Distil off pyridine and store with protection from moisture. The water content of pyridine must not exceed 1 mg per ml. - Karil. Fischer ren cc a t: Proper.-' Iron: Dissolve 65g c'f iodine in 100 ml of "pyridine for Xarl Fischer Kethod", cool in ice ar.d pass dry sulfur dioxide through the solution until the increase of the weight of the solution is 22.3g. Dilute with "methanol ' for KfU'l Fischer method" to 500 ml and allow to stand for more than 24 hours Since this solution deteriorates continuously it should be standardised before use. Protect from light and moisture and store in the cold place. Standa sal a.tier, of the }'--r 1 FirflV-',r Ho" "e"t: Primary hoiked: Place about pi ml of _wnnnol in the titration vessel and ti train with the Kart Fischer .F e to the cuaractoristi c end-point. Quickly add about 2C3 eg of sodium tartrate dihydrate, accurately weighed, and while stirring vigorously, again titraio, to tire cnc-pomt. The water equivalence facior, f, in mg of water war ml of reagent, is reprosorri ou by the formula. O.lpoo V."/y, in which il is the vroi in nig of the sc. hr. , - , A ; . i ^0, V is the volume in ml oi cno reagent consumed i n M., J Oi in a dricn 1,0-10 r measured.. Dilute Tiic standardixuii c K a r 1 i i s ? n c r re a eg n . the cos*lid,* winco inva ir.c iu,.p ,m .nano J. arl Fir,char hoi hod" ^ i-,.*!. or Mi`. k>^'T i :*cc . cl.or '*o i fCG0 --j f'/iO'.L '.L >> C #- _i O * C Cl ij J wu. b Oa UiiC . . \j t I . 'J. l 4 i \ K S-! `V J- \S *- * * Vt-iJ- C ASI 00003107 ' Stand-.:'/' i on: Place 20 nl of '.,'atar-Kothnnol otandsrd Solution ncasureu accurately into a titration flash and titrate the Karl Pi ocher reayent to the point at whica the calcur of the solution just chan03 frer. brownish yellow to reddish brown as directed under Proceauro* toe wntcr c-r. .cu., .. , -.r ny per m. Gi ,,auCr no inar^i Standard Solution :I.rs yiven by the follc-winy formula: f x. (:il of Karl r.chcr roayont) ' (carr ho to ~w.tion ) ;J of VA.tor-a j vunnol ) Standard Solution ) proa: Tho titration with the Karl fischcr reagent should bo performed no tho same temperature r.s that rood in the standardisation. The nitration '.;lth Karl fischor reayent r.ay bo performed by any of tho followiny methods, unless otherwise specified. In olcctror.esrical determinations, usually a bach nitration jives a better result. In colorless solutions, the end point of the nitration may be determined visually as tho point at vhioh tho colour of tho solution chary r- from bro-.mish yellow to reddish brown colour(vice versa in tho caso of a , bach titration). In coloured solutions, tho end point is dole-mined ciectror-iOtricalDy by the dead stop method. Kor electro,metrical determination, inverse two platinum electrodes in the solution bo titrated and ness a Ac; to current (5 to 10 rh crooe.percs) by rur.: pulatir.j the variable resistance of the circuit. Add, Karl Kischor reayent dropwisc with tho titra v.c 0*1 p ITO the noodle of tho nicronnteter will swir.y noticeably, but will return to the original position within a few seconds. At the end point of the titration, a nliyht excess of the reayent will increase the flow of current (`/O to IfO microamperes; for pO seconds or lor.yor. In bach titration, the r.eedit of the r.icroanr.oter will scale out when an excess of Karl Kitcher reayent is present, and will return rapidly to the oriyinal position unen tho titration attains the end point. The apparatus- utilising a i/.ayic eye (olectron-ray tube) nay be employed instead of a liicroan.wctcr. Since f for the Karl riser.cr reaycr.t decreases continuously, it may 00 001at,:za 0y 11 .ration 0, 20 tu o ,,e. ,..r.e ,,a*. 0.. u ,L.utetu Solution measures. aco^-r.- ,,,,ay a1.1.0 ,,cd *u.c.r o ,a.oe. a...... H.G., 0. 'vator^Kethancl Gtanearcl Solution and by calculating by the folic,:iny* 1 r- ml of '.'ator Kcthr.r.ol r- .3 c 1 .. - - . ; 'i_L 0;. ..hi*I ,i, ,.* * A.T /va^u'r.i conjjujj.o cl .iTi . ft c v-- k. a on PotT-i -- 1 ion of V--'l'In- 2 -r:: /h P3f.ce alouJ, 25 rl of the solvent in the titration vessel and tit: a y. v., L.a t.io Karl ?;sch, r Acsyen.t to t:ie end-point. Cpy_e il' ; la. Tho water content of the / .rr.Tilo, in ; y, is obtoinen by r/Of :-f :- t ; - vo',' ; of the rw; ,i -wed in titratin'; fh,v ijnr'.plc ,3,' t:e r, , `a., 1 ..a c tor, i.n0...t";.e rcayeat. J: .1 .. 1570, 3\-od taa'J s Cade:-: 15C'I J;u\.Slv.dard.j <>f Pood Additives,1 AS1 00003108 K3TP0T) 10 3.10 The detection of free ccidit-r -jv, aT^oerol 1* Pr-lnci^l o of metV-d; Colour charge with methyl orange. 2. P icq-.yd n; Methyl orange indicator ~ dissolve 0.5g of methyl orange in one,litre,of distilled, water. 3. procedure; To 50 ml of freshly boiled and cooled distilled water add 4 drops (approx 0.2ml) of the methyl orange indicator, and adjust to tho neutral colour of tho indicator. To 25 ml of the neutralized water add 25 ml of the sample and shake vigorously for 5 seconds. Allow the layers to separate and note any change in the colour of the aqueous layer when compared with that of tho neutralized water. A change of colour towards redindicates the presence of acid. 4. Calculations end remits: There should be no acidity to methyl orange. 5. Reference; British Standard specification 19975 19^2. ASI 00003109 irarnoi) 11 3.11, The determination of snlfated. ash 1 PrincitO 3 of method 2. Reagents: sulfuric acid - contains not less than 97^ w/w of W 3- procsduT'e: Heat 5 G until it ignites find allow to turn. Cool the residue moisten with sulfuric acid, and ignite. 4. Calculation and results: The residue should not weigh more than that specified. 5* Reference: British Pharmacopoeia lS'-'S p.444* I II ! t ASI 00003110 ????KOD 1.2 3.12. The detection of corner jn rlvcerol 1* Principle of method: Precipitation as copper sulphide. 2. Replants: The reagents shall he of a recognized analytical reagent quality. Distilled water or v.'ater of at least equal purity shall be used. Hydrogen sulphide, saturated solution in water, freshly prepared. Hydrochloric acid, 3hT solution. 3. 1 procedure: Hi* 10 nil of the sample with 30 ml of water, 1 ml of the hydrochloric acid did 10 ml of the hydrogen sulphide solution. Report whether or not any colour is produced. 4. Calculations and results: There should be no colour produced. 5* Reference: British Pharmacoepia 19^3* ASI 00003111 kttfod 13 13.13 The dotion of tov, in five oro 1 This method is based on that recommended in the British Pharmacoepia, 19^3* I* Principle o^ r.~;thod; Colour reaction with thioglycolic acid 2. Ppi-r-entn: The reagents used shall bo of a recognised analytical reagent quality. Distilled water or water of at least equal purity shall be used. Th j oglvcol ic acid 9Pb. Take care not to allow concentrated thioglycolic acid to come into contact with the shin, as it causes painful wounds. Ammonia solution d = 0.880. Hydrochloric acid, concentrated d = 1.13 Citric acid 20^ solution (w/v) Standard iron solution - Dissolve 0.173d' of ammonium ferric sulphate in 100 ml" of water. Add 10ml of the hydrochloric acid and dilute to 1000 ml. This solution contains 0.02 mg of iron in 1 ml. Dilute 100 ml of this solution to 1000 ml to form the standard solution containing 0,G02mg of iron in 1 ml. 3 ATvn.-rrtus - One-nark volumetric flasks of capacities 100ml and 1000 ml to 3.0. 1792. Kessler cylinders of capacities 5 ml to B.S. ol2. 4 Procedure: heigh 20g of the material to the nearest O.Olg, into a Kessler cylinder. Add 2 ml of the citric acid solution end 2 drops of the thioglycolic acid. Kobe alkaline with the ammonia solution, dilute with water to u)0 ml and alio:: to stand for 5 minutes. At the same time, in another Kessler cylinder, mix 5 ml of the standard iron solution with 40ml of water. Add 2ml of the citric acid solution and 2 drops of the thioglycolic acid, make alkaline with the annouk. solution,. Dilute to 90 ml witjh vj&ft,or and allov: to stand for 5 uinul s. Compare Lhe depths of 1 colour s'of solution in t itG i i jU^, . , i 1 -' " ~ 1 VJ-I . Cfl'ALvj-r- _ ',_A.fLdJ-'ufu T'he-re should not bo mono than 0,5?pm iron conn , c..louiat:d Ke. 0. ' nh Sir aciurd Speciffeat.ion 2o?"j-A: 1904. A A ''003112 3.14. The detection of chloric's in /rV'cerol 1. Principle of rethod; Estimation as Silver chloride. 2. Replants: The reagents shall be of a recognized analytical reagent quality. Distilled water or water of at least equal purity shall be used. Nitric acid, dilute solution. Dilute 10.5^1 nitric acid,' d = 1.42, to 100 ml with water. Silver nitrate 0.1N solution 3. Procedure; Dilute 10 ml of the glycerol to 100 ml with water. Place 10 ml of this solution in a boiling tube, add 0.25:nl of the nitric acid solution, 0,5 ml of the silver nitrate solution and mix. Report whether any turbidity is produced. 4. Cflcnlrtions end results There should be no turbidity produced. . Refercr.ce British Standard Specification 2621-5! 1964* ASI 00003113 K-STFOD 15 1. Principle of method Titration against standard base 2. Reagents The reagents used shall be of a recognized analytical reagent quality. Instilled water or water of at least equal purity and free from carbon dioxide shall bo used. Sodium hydroxide 0.2pN solution. Sulfuric acid 0.25N solution Phenolnhtfralein indicator' 0.gg ethanolic solution, prepared by diluting Ig of phenolphthalein in 200ml of 95g (v/v) ethanol, and adding 0.5F sodium hydroxide solution cautiously until a faint pink colour persists. 3* Procedure Reign 5^2 of the veil mixed sample into a JCOml round-bottomed flask. Add 100;.il of hot, carbon dioxide free water and 1ml of phenolphthalein indicator. If the solution is alkaline, adjust to neutrality with the sulfuric acid solution. Add fron a burette 15 ml of the sodium hydroxide solution, connect the flask to a reflux condenser and heat to boiling. Soil for five minutes, allow to cool somewhat and wash down the condenser with a little water. Disconnect the flask, close it with a stopper carrying a soda-line tube, and cool. Titrate with the sulfuric acid solution. Carry out a blank test at' the same time, but using 140 ml of the water. 4. Calculnt ' ilia Fatty acids and esters, per cent a: 0.775 (rl2-I!) v,-ho.ee T2 - volume, in millilitres for blank. it. -1 if 0.25H sulfuric acid required o; ,pl o J.V ASI 00003114 J.3TH0D 16 3.16. The detection of acrolein in rlycerol Principle of method Reaction of acrolein with sodium nitroprusside to give a blue to green colour in the presence of piperidine. Reagents Piperidine solution in waxer. A 1 in 5 solution of piperidine Sodium, nitrorrucside solution Dissolve lg sodium nitroprusside in sufficient water to make 20 ml. Prepare fresh "before use. Procedure Add 1 drop of glycerol on a filter paper previously *" moistened with one drop piperidine solution and one drop sodium nitroprusside solution. Results Ro blue to indigo blue to green colour is produced. Reference The Japanese Standards of Food Additives 2nd Ed 1970 p.271. I 003lls MSTKOT) 17 3-17 * Tha 'measurement of Refractive Index The refroc [ ive ind.cz of any substance is the ratio of the velocity of light in vacuum to the velocity in the substance. It is equal to the ratio of the sine of the angle of incidence to the sine of the angle of refraction. In general, it varies vfith the wavelength of the light, and also with the temperature. In these standards, the refractive index nj)t' is defined as the refractive index to air measured at the temperature of t, using the D line in the sodium spectrum. The refractive index is measured vjithin +0.2 of the specified temperature for each substance. ASX 00003H nUTHCD 18 3.18, Tho doterminaticn of ash in glycerol mono, di and tri acetates an d pro;) r.r,~1,2-6g 1 1. Principle of bathed: 2. Reagent r.: .3* Procedure; Slowly burn 50 nil of the solvent, in several portions, in a weighed platinum or silica basin, and gently ignite until all carbon"*,iccous matter has disappeared. Cool in a desaicator and weigh. 4. Calculotions end results; Calculate the ash as percent by weight of sample, 'lucre should not be more than specified by weight of ash. 5. Reforonec; British Standard Specification 1^94: 1950* ASI 00003117 METHOD 19 3.19 The determinateon of sulfate .in rdycerol mono diacetates 1. Principle nJ trmethod: precipitation as ba.rium sulfate. 2. Reament: nn cPIo^ide solution A solution containing 10g barium chloride in 100 ml distilled v;ater. 3* Anoarat-iis* Goc,--k crucible fitted with an asbestos pad. 4 Procedure: Dilute 50 ml of the solvent to 100 ml with distilled water and heat to boiling point. To the hot liquid add 5 ml of a boiling solution of barium chloride drop by drop; conlimie boiling for a few minutes and set aside a hot plate for at least 4 hours. Hash the precipitate with hot water by decantation pouring the supernatant liquid and washing through a prepared Gooch crucible fitted with an asbestos pad. Transfer the precipitate to the filter end wash it thoroughly with hot water. Finally dry the crucible and ignite it to constant weight 5 Calculation and r^suHs; For the increase in weight of the crucible calculate the sulfates expressed as SO/j, percent by weight of sample, Ba S04 x 0.4135 - S04 6. Reference; British Standard Specification 1594; 1950. Vi-i' AS I OOOO -< i i - ].sr:-roi> 20 3.20. The dertorrr'irn'fcion of chloride." in glycerol rono and diacetntes Prlricirle. of fna method: Estimation of chloride us silver chloride. He?" merits glacial acetic acid/analytical grade.potassium chromate solution. A 5'A solution in water. Silver n-itrrtc -:pi-itj on. A 0.1N solution in distilled water Procedure Dilute 25 ml of the solvent to ICO ml v:ith distilled water. Add 2 ml glacial acetic acid and 1 ml potassium chromate solution end titrate with 0.117 silver nitrate solution until the red coloration is permanent. o rl T5 "> r-1 ' 1 Calculate tie chlorides thus found .chlorine, ,C.l,. percent by weight of sample. 1 ml 0.117 A3KO3 - 0.00355g Cl. Bp-fore^eo British Standard Specification 1594: 1950* ASI 00003119 ISTPOD T9 3,19. The deterniration of sulfate in glycerol mono diacetates 1. Principle nJ the method: Precipitation as barium sulfate. 2. Rongent; ^---rjun r-'r1 Qfjds solution A solution containing 10g barium chloride in 100 ml distilled water. 3* Anpr.rains: CoqcKcrucible fitted with an asbestos pod. 4. procedure: Dilute 50 ml of the solvent to 100 ml with distilled water and heart to boiling point. To the hot liquid add 5 ml of a boiling solution of barium chloride drop by drop; continue boiling for a few minutes and set aside a hot plate for at least 4 hours. Wash the precipitate with hot water by decantation pouring the supernatant liquid and washing through a prepared Gooch crucible fitted vath an asbestos pad. Transfer the precipitate to the filter end wash it thoroughly with hot water. Finally dry the crucible and ignite it to constant weight. 5* Calculation end rw;Pts: For the increase in weight of the crucible calculate the sulfates expressed as S0^, percent by weight of sample. Ba R0^ x 0.411S - S0^ 6. Reference: British Standard Specification 1594*. 1950. ASI OOOO ; i ISPHOD 20 3*20. The dot c-~:ination cf chlorides in glycerol r.ono and dincetr.te3 Principle of in a method; Sstimation of chloride as silver chloride. R or 55 glacial acetic acid/analytical a-rade. potassium chromate solution. A 521 solution in water. Silver nitrate -.elution. A 0.1N solution in distilled water Bilute 25 ml of the solvent to ICO ml with distilled 'water. Add 2 ml glacial acetic acid and 1 ml potassium chromate solution and titrate with 0.11T silver nitrate solution until the red coloration in permanent. Calculation:- and P_?ru.:'h'.r: Calculate tie chlorides thus found as .chlorine ,G1,, percent by weight of sample. 1 ml 0.1hT A3NO3 0 0.00355s Cl. Refer once British Standard Specification 1594: 1950* ASl 00003121 KCTHOT) 19 3-19. The determination of sulfate j-IL/dl;vcerol mono diacetates 1* Principle the r,?l'r'od: Precipitation as barium sulfate. 2. Reader:!:; T',---rhim ch^c-id-?. solution A solution containing lOg barium chloride in 100 ml distilled water. 3* Apparatus: Gocckcrucible fitted with cm acbesios pod. 4. Procedure; Dilute 50 nil of the solvent to 100 ml with distilled v:stor and hep.t to boiling point. To the hot liquid add 5 ml of a boiling solution of barium chloride drop by drop; continue boiling for a few minutes and set aside a hot plate for at least 4 hours. Wash the precipitate with hot water by decantation pouring the supernatant liquid and washing through a prepared Gooch crucible fitted with an asbestos pad. Transfer the precipitate to the filter end wash it thoroughly with hot water. Finally dry the crucible and ignite it to constant weight. 5* Calon3.at j or. end r r-.u113; For the increase in weight of the crucible calculate the sulfates expressed as 30^, percent by weight of sample, Ba' R0^ x 0.41 IT* = SO^ 6. Reference; British Standard Specification 1594: 1950. v- ASI 00003122 I-rarHOD 20 3*20. The determination cf chlorides in glycerol rono a-fid dinoetstp G Principle of the method: Estimation of chloride as silver chloride. Pcygert-s glacial acetic acid/analytical grade.potassium chromate solution. A 5g solution in water. Silver nitrate -elution. A 0.117 solution in distilled 'water Dilute 25 ml of the solvent to 100 ml with distilled water. Add 2 ml glacial acetic acid and 1 ml potassium chromate solution and titrate vrith 0.117 silver nitrate solution until the red coloration is permanent.* 1 jla-loiilpticr.,. v* rl ' i J` s: Calculate tvochlorides thus found as .chlorine,. ,G1, percent by weight of sample. 1 ml 0.117 A3NO3 . O.00355g Cl. 'RpOerevce British Standard Specification 1554: 1950* ASI 000 *1 2.3 mathcd 21 3*21' Method for th et ormination of ester content of glycerol 1. Price 1 ploof ; jt; od 2. Re?gents; The reogents used shall be cf a recognised analytical reagent quality. Distilled water, or water of at least equal purity, shall bo used throughout and shall be freshly boiled and cooled. in 10U ml of etha.no! and make faintly pink by the addition of 0.11? sodium hydroxide solution. hydro;-::de solution into each of two dry 2J0 nil conical flasks with ground-glass joints. Close the fl with their glass stoppers. By means of a weighing pipette, transfer 2.0 to 25j of the sample, weighed to the nearest O.COlg, into one of the flasks. Attach the flasks to water-cooled reflux condensers with ground-glass joints and heat for one hour in a boiling-water bath. Withdraw the flasks, still carrying their condensers, and irmer.se then in cold running water. When cool, -wash down the inside of each condenser with two 20 ml portions of -water. Disconnect the flasks and wash each joint with a further 20 ml of water. Add 0.5 ml of the phenolphthalein indicator and titrate the mixture immediately with the hydrochloric acid until the pink colour is just discharged. 4 Calcu 1 a t i0n rd_reou Its: For give i-ol trices bate: aster content, calculated as glycerol t nacexua o, (Cil COO)., 0 3ir, j 0 nj percent by weight = 7*27 (T, ~ T^) p0T. vcerol di ta;. c: Deter content calculated as glycerol C k core t;.' w i of acetic acid cb'bormined in method 4 ASI 00003124 where 1h = volume in millilitres, of IT hydrochloric acid solution required "by the blank, T2 = volume, in millilitres, of IT hydrochloric acid solution required by the test sample. Vv'4 = weight, in grammes, of sample. The ester content should ho the limits specified. 5* ftoferonco: British Standard Specification 1997: 19^2 < ASI 00003125 I.HJTHOn ?g 3*22. The doh''nt.ion or 'T-k or and ^lyoerol in rlynnrol rtlecetrtc Vrrr.cinlo of method; Inniscibility of water and glycerol in `benzene. He:.-rentBenzene, analyt.ical grade. Proccnirre: Fix 50 ir.l of benzene with 10 ml distilled water and shake vigorously from time to time for 30 minutes. Allow the mixture to separate into two layers. Remove 2pml. of the clear benzene and -add it to 10 ml of the glycerol diacetate in a dry glass-stoppered cylinder of about 100ml capacity. Allow to stand for 30 minutes, shake vigorously and. examine for opalescence. Result; There should bo no opalescence. Reference; British Standard Specification 150/j: 1950. 1 * ASI 00003126 '_L_3UjHjf*" * - jam <0EX in al. of water meets the lge V o3, using 20 meg. of lead ml. into a tared 125-ml. heated at 105 to constant ness on a steam bath. Heat tant weight, cool in a desicca- 'issolve 15 grams of sodium ml. of bromine, stirring to ef)0 ml. with water. Transfer . glass-stoppered Erlenmeyer d 10 ml. of a 1 in 5 solution of nple. Allow to stand for 15 f potassium iodide and 10 ml. L N sodium thiosulfate just to 'erform a blank determination ,e volume of 0.1 N sodium thiorequired for the sample is not acher Titrimetric Method, page J-cIosed containers. ve. ^SOLE hole ^CHtCHi Mol. wt. 150.22 ving a characteristic anise-type It is soluble in most fixed oils iycerin and in propylene glycol. ind 1.5055 at 20. d 0.943. FOOD CHEMICALS CODEX 543 Limits of Impurities Arsenic (as As). Not more than 3 parts per million (0.0003 per cent). Heavy metals (as Pb). Not more than 40 parts per million (0.004 per cent). Lead. Not more than 10 parts per million (0.001 per cent). TESTS Refractive index, page 785. Determine with an Abbe or other refiractometer of equal or greater accuracy. Solubility in alcohol. Proceed as directed in the general method, page 746. One ml. dissolves in 5 ml. of 80 per cent alcohol and re mains in solution upon further dilution. Specific gravity. Determine by any reliable method (see page 4). Arsenic. A Sample Solution prepared as directed for organic com pounds meets the requirements of the Arsenic Test, page 720. Heavy metals. Prepare and test a 500-mg. sample as directed in Method II under the Heavy Metals Test, page 763, using 20 meg. of lead ion (Pb) in the control (Solution A). Lead. A Sample Solution prepared as directed for organic com pounds meets the requirements of the Lead Limit Test, page 772, using 10 meg. of lead ion (Pb) in the control. Packaging and storage. Store in tight, fall containers in a cool place protected from light. Functional use in foods. Flavoring agent. PROPYLENE GLYCOL 1,2-Propanediol; 1,2-Dihydroxypropane; Methyl Glycol CH,.CH(OH).CH!OH CjHsOj Mol. wt. 76.10 DESCRIPTION A clear, colorless, viscous liquid having a slight, characteristic taste. It is practically odorless. It absorbs moisture when exposed to moist air. It is miscible with water, acetone, and chloroform in all propor tions. It is soluble in ether and will dissolve many essential oils, but is immiscible with fixed oils. , IDENTIFICATION A. Mix 500 mg. with 3.6 grams of triphenylchIoromethane and 5 ml. of pyridine, and heat under a reflux condenser on a steam bath for 1 -, ASI 00003127 jPtX P ,1^ ivarm acetone, and stir filter, evaporate the filtrate ,,ight in a refrigerator. Filter '.nt pyridine (three times) and obtained melt at about 176 l>0tassiuin bisulfate. A fruity j* beated to dryness, no sharp, weight, of C3Hs02. 189. .037. rts per million (0.0003 per cent). ban 10 parts per million (0.001 ia 0.07 per cent. nlumetric flask about 300 mg. hing pipet, dilute to volume with his solution into a 125-ml. Erlen- 1, swirl, and let stand for I solunon of sodium bicarbonate, irsenite and 1 ml. of a potassium id enough sodium bicarbonate so II remain undissolved, and titrate burnt and continuing the titration tank determination (see page 2) Panb ml- of 0.1 N iodine is equiva- 100-ml. sample distils completely my reliable method (see page 4). alein TJ3. to 50 ml. of water, then the solution remains pink for 30 rf the sample, accurately measured, oxide until the original pink color Not more than 0.2 ml. of 0.1 A' FOOD CHEMICALS CODEX 565 Arsenic. A Sample Solution prepared as directed for organic com pounds meets the requirements of the Arsenic Test, page 720. Heavy metals. A solution of 2 grams in 25 mi. of water meets the re quirements of the Heavy Metals Test, page 763, using 20 meg. of lead ion (Pb) in the control (Solution A). Residue on ignition, page 786. Heat a 50-gjam sample in a taxed 100-ml. shallow dish until it ignites, and allow it to bum without further application of heat in a place free from drafts. Cool, moisten the residue with 5 ml. of sulfuric acid, and ignite at about 800 for 15 minutes. Water. Determine by the Karl Fischer Titrimetric Method, page 804. Packaging and storage. Store in tight containers. Functional use in foods. Solvent; wetting agent; humectant. (CiHuOi), PROPYLENE GLYCOL ALGINATE Hydroxypropyl Alginate; Algin Derivative Equiv. wt., Calculated, 234.20 DESCRIPTION The propylene glycol ester of alginic acid (see Alginic Acid, page 20) varies in composition according to its degree of esterification and the percentages of free and neutralized carboxyl groups in the molecule. It occurs as a white to yellowish, fibrous or granular powder. It is prac tically odorless and tasteless. It dissolves in water, in solutions of dilute organic acids, and, depending upon the degree of esterification, in hydroalcoholic mixtures containing up to 60 per cent by weight of alco hol to form stable, viscous colloidal solutions at a pH of 3. IDENTIFICATION ^ A. It responds to Identification Tests, A, B, and C under Sodium Alginate, page 600. B. Transfer 20 ml. of the saponified solution obtained in the deter mination of Esterified carboxyl groups into a 250-ml. Erlenmeyer flask, add 50 ml. of 0.1 M periodic acid, swirl, and allow to stand for 30 minutes. Add 2 grams of potassium iodide, titrate with 0.1 N sodium thiosulfate to a faint yellow color, and then dilute the mixture to 200 ml. To 10 ml. of this dilution add 5 ml. of hydrochloric add and 10 ml. of modified Schiff's reagent. A pink color develops in about 20 minutes (formalde hyde). To another 10 ml. of the solution add 1 ml. of a saturated solu tion of piperazine hydrate and 0.5 ml. of sodium nitroferricyanide T.S. A blue color develops (acetaldehyde). Note: Oxidation of propylene glycol alginate yields formaldehyde and acetaldehyde. ASI 00003128 j PJUU <-H,EMICAtS CODEX jd tent and not more than the equivalent ol IC1 after drying. Between +23.5 and +25.5. re than 3 parts per million (0.0003 per cent). Not more than 20 parts per million (0.002 parts per million (0.001 per cent), re than 0.5 per cent. it more than 0.25 per cent. > mg., previously dried at 80 for 4 hours mL of water, add bromothymol blue T.S., hydroxide. Each ml. of 0.1 N sodium Img. of CjHjNCh.HCl. . After drying at 80 for 4 hours, deterhloric acid containing 125 mg. in eachml. prepared as directed for organic com>f the Arsenic Test, page 720. 1 test a 1-gram sample as directed in 'is Test, page 763, using 20 meg. of lead A). ared as directed for organic compounds iLimit Test, page 772, using 10 meg. of y at 80 for 4 hours. 1 gram as directed in the general in 'l-closed, light-resistant con- betitute; flavoring agent. FOOD CHEMICALS COOCX 309 CjHjOj GLYCERIN Glycerol CHjOH. CHOH. CHjOH Mol. wt. 92.10 DESCRIPTION A clear, colorless, syrupy liquid, having a sweet taste. It has not more than a slight characteristic odor, which is neither harsh nor dis agreeable. It is hygroscopic and its solutions are neutral. Glycerin is miscible with water and with alcohol. It is insoluble in chloroform, in ether, and in fixed and volatile oils. IDENTIFICATION Heat a few drops of glycerin in a test tube with about 500 mg. of potassium bisulfate. The characteristic, pungent vapors of acrolein are evolved. SPECIFICATIONS Assay. Not less than 95 per cent of C3H803. Specific gravity. Not less than 1.249. Limits of Impurities Acrolein, glucose, and ammonium compounds. Passes test. Arsenic (as As). Not more than 3 parts per million (0.0003 per cent). Butanetriols. Not more than 0,2 per cent. Chlorinated compounds (as Cl). Not more than 30 parts per million (0.003 per cent). Color. Passes test. Fatty acids and esters. Passes test (limit about 0.1 per cent, calculated as butyric acid). ^ Heavy metals (as Pb). Not more than 5 parts per million (0.0005 per cent). Readily carbonizable substances. Passes test. Residue on ignition. Not more than 0.01 per cent. Assay Sodium Periodate Solution. Dissolve 60 grams of sodium metaperio date (NalO,) in sufficient water containing 120 ml. of 0.1 N sulfuric acid to make 1000 ml. Do not heat to dissolve the periodate. If the solution is not clear, filter through a sintered-glass filter. Store the solution in a glass-stoppered, light-resistant container. Test the suit ability of this solution as follows: Pipet 10 ml. into a 250-ml. volu metric flask, dilute to volume with water, and mix. To about 550 mg. ASI 00003129