Document 8bvzqEJXNxg3nqow6YK0wj6d

w -NaCl Systems Reversed UqMid-Liquid Partition in Determination of ; XuT X 10-1 Polychlorinated Biphenyl (PCB) and Chlorinated Pesticides in Wate 4.23 dkO.M 4.64 0.04 3.37 0.07 0.301 0.008 0.480 0.008 0.449 0.018 i 0.442 0.048 j | akcn and Mg found ; constant in So. 1-3 I eviations are due to ; carried into the ti- gcagt Ablins} and Sflren Jensen* '.Mtu e Ar^y .-jzl L> icy cf S-:drh:L~. S-r04QS.Sr.:rkM.-* !<) gnew method based on an appfication of the common reserved liquid-liquid partition method is described ler the extraction of chlorinated pesticides from water, le this methed the water is passed through a filter a grams) containing a mixture of a-undnennn and Cerbowax 4MB monostearate on Chromosorb W, and At absorbed postkldns art alutod with petroleum ,;h*r (10 ml). Whan detected by means of a gas ^rsmatosraphlc system with an electron capture iitactor, the sensitivity is 10 ng/m' of lindane with a ample size of 2N liters. The recovery of added pnstidtfss was 9t-U0% (DOT, 80%) and far PCS, 91-100%. Rohm and Haas (5) and also found to be highly efficient the extraction of chlorinated pesticides from water, extraction of the filter material gave, however, poor recov Good results both in extraction and recovery from f material were found in a method based on the reversed liqi liquid partition method with partition from water to hy< phobized carrier coated with a bpc^hfic stationary pi followed by recovery from the column by means of a s amount of petroleum ether (10 ml). ace* of heavy metal L'd solution and make Quanto xxcent years, many attempts have been made to EXPERIMENTAL 1 using potassium cy! ;t curve fitting method jean not be estimated ! bought of the actual 1 s, ics for the unknown Station before starting . The successive aponverge when the ini- jnenmne the presence of chlorinated hydrocarbons in water. ]ke two methods most often used are based either on con tiguous extraction with an organic solvent (7, J) or adsorption a s filter containing activated carbon (J). These methods , however,1 rather time consuming owing to a long ex Taction time, ioth from the water and.from the carbon. The sensitivity of the different methods depends mostly on it way of detection and the used volume of water. Thus Uhn and Wayman (/) extracted several hundred liters of atcr with petroleum ether. The speed of extraction was Reagents and Equipment. n-Undecane, (purum, b.p. i 196 C) is shaken with portions of concentrated sulfuric (p.a.) until the acid is colorless. The undecane is then pa through a column of activated alumina (12 hours at 250 Petroleum ether (Skellysolve B, b.p. 60-70 C) and ace (p.a.) are distilled through a 1-meter column filled sadels and insulated with glass-wool and aluminum foil, head of the column is fitted to a still-head condenser adju for 90% reflux. The solvents arc tested on the gas chrotr graph after evaporation to the same degree as in the anal Carbowax 4000 monostcaratc (GP 27) was obtained I alculation converged using any set of the .,f 10% for the true ,i and Xmi/Xmy. Althe initial values are be presumed empiri: orvc. j of the titration data restricted in the range >. 4,7, and 10 in Table li-1 liter/hour and recovery of added pesticide was 83-100%. t range of compounds was detected with an electron affinity hector at the 0.2-340 ppb level. Rosen and Middleton (2) xd activated carbon and 2000 liters of water and extracted k chlorinated hydrocarbons from the carbon with chlorform. The recovery was 75-86% and the 2.5-ppm level as reached With infrared detection. Brcidcnbach (J) found at 35 hours' extraction with ahloroform was necessary for anplete recovery of the chlorinated hydrocarbons from the xbon after previously drying the filter material for two Analytical Engineering Laboratories Inc. Chromosori was 60-80 mesh, HMDS treated, and acid washed (Jo Manville). Sulfuric acid was p.a. (Merck). The filter column was 30 cm X 1 cm i.d. with a glass-1 disk G 1 (100-120 ft). A 10-ml graduated centrifugg tube was used. The gas chromatographic column borosilicatc glass, 160 cm X 0.20 cm. All the glassware is washed with detergent, heated mixture of sulfuric acid-nitric acid (4:1) to 70 C and ri> with distilled water. After cleaning, the glassware is che by shaking with n-hexane from which 10 pi is injected or of a value, and the re- !iyiat 40 *Q gas chromatograph. The gas chromatograph with ience of changing the te treatment of using le, iraphy that Galmagitc ties of colored impuriilmost no influence on ; docs not take more oess a set of titratioa Recent progress of these two methods will be found in an vtflent review by Thornburg and Beckman (4). Our intention in the present work has been to develop an her method than the above mentioned, in which it could be wibie to reach the proposed level of chlorinated hydro-' xbons in nafiwal water in Sweden. Because of the oleophilic character of the chlorinated nticidcs, a possible method might be based on the com ply used reversed phase partition method, detector was a Varian Aerograph 204, with a Speedo G-l mV recorder. Paper speed was 12 inches/hour. Gas Chromatography. The columns are HMDS-tre and filled with 80-100 mesh HMDS-treated Chromosori covered with either 4% methyl silicone oil (SF 96), or fluorsilicotie oil (QF I). The carrier gas is nitrogen pur with a 6-inch molecular sieve. Gas speed is about 3C per minute. Detector and injector temperature is 205 220 *C, respectively. The column temperature was ch< to give DDT a retention time of 20 minutes (about 190 tting method wffl be hrtition of organic material from water by means of wberiite XAD (a cross-linked polymer) was first used by Preparation of Column Material. Ten grams of Carbo 4000 monostearate and 30 grams of undecane are disso in 100 ml of acetone in a one-liter round-bottomed fl /keceptad July 1, 1970. : Present address. Institute* fflr Vatten--och Luftvirdsfonkning. -xtniag Krfaliau 6g 47D, 114 28, Stockholm. [ Prsssot address, LantbruksMgskolaii. Ksmi I, Uttiaw, 730 07. f task. One hundred grams of Chromosorb W is added follower additional acetone to cover all support. The aceton evaporated in a rotavapor apparatus under slightly dii ished pressure. Partition and Precipitation Procedure. Three grams L Kahn and C. H. Wayman, Anal. Oram., 34, 1340 (1964). - A. A. Rosea, and E. M. Middleton, *44,31, 1729 (1999). -1 A. W. Brridsnbach *t d, "The Identification and Measurement of Chlorinated Hydrocarbon Patiddcs in Surface Waters," U. *. Department oftbs Interior Federal Water PoMotion Control Adnaaktration, NavsnRnr 1964. -- 10 W. Thornburg and H. Beckman, Anal. Qml, 41, 149R (1969). the column material are weighed into the column whic then fitted to the outflow of the water container by mean an all-glam fitting. In laboratory work, t^e lower enr the column is connected to a water suction pump ytd in field work, to any other kind of vacuum pump. The vaci (5) Rohm A Haas, Cktm. Eng. Newt, 44, 34 (Jan. 17, 1966). DSW 332450 ANALYTICAL CHEMISTRY, VOL 42, NO. 13, NOVEMBER 1970 1 STLCOPCB4079026 Table I. Results from Recovery Experiments 12 R r s s s s a S *23883 Q J-!. *O < -E so, tt tu Q SR R S S 3 8 8 8 Q | 8- P - S38 | ?S ? R 3 * 3 8 <" a s R s $ 'O'*N -- is II * *83* II o O O v> a9 X:s~ <.n <f\ n s D Q o Q Q DeC !5 Q w Q Q eo-i c tj < O c c3 V Xa II;| 83 38R3333 S3 E~ fc <0 <0 <0 \C *20 3 ** E K K K t? t? ft ft ft 8 ft ft + ++ .-.--j'I'IjIiI-.- ,, !Sc3Kal3|5|a|5|a| liaJ |C82i<2:So5oKDo^3o3Ko 5-- 5 --Dts--*5 is mljustcd lo Hive an outflow Ix-lWven 65 ami I 30 ml of wai0 per ininnlc. l;or analysis of waste waters ami olher wain with high parliele content, Ihe residue is estimated separate^ in the particles and in the water. Before filtering such wnitrv 300 mg of aluminum .sulfate per Jiler is added and afia sedimentation of the solid, the water is decanted and passe; through the filler. For extraction of the solid, see hdo --pp C This two-step method will also avoid blockages in the column Elution of Chlorinated Hydrocarbons from the Color* When the filtration is finished, the suction is continued fo' PP D a few minutes. I'elroleum ether is then added to elute tS> pesticides; 10 ml of the diluent is collected in a graduate; PP C centrifugation tube. The extract is further prepared an; analyzed as described below. Extraction of Solid from Aluminum Sulfate Precipitation The sediment is air dried and two grams or less is extracts >-Aid r with 6 ml of acetone in a small column (30 cm X 1 cm followed by 5 ml of petroleum ether. The extract is collects: in a 25-ml bottle filled with distilled water and shaken. 71 petroleum ether is then treated as described below. j Treatment of Extract before Gas Chromatography. On' ml of the extract is transferred to a 3-ml test tube contains 1 ml of concentrated sulfuric acid. The tube is covered witi( aluminum foil, shaken carefully, and then centrifuged. TV' Figure I a. < from distilled b. Gas chri aatural water sulfuric acid is chilled in a mixture of carbon dioxide ice am{ acetone. After decantation of the petroleum ether, a 10-j.1, portion-is injected on the gas chromatograph. If the injcctio: j gives too low peaks, the remaining 9 ml is concentrated k! 0.9 ml in a SO C water bath with a stream of purified nitrogej and treated with sulfuric acid as above. i Gas Chromatographic Procedure. The extract is injects! on two columns, one SF % and one QF 1. Neither of thes columns gives a full separation of the chlorinated hydro j carbons present in the water. The combination, however,) gives a rather good possibility for calculations. it was diffici liters in 24 h< Recoveryprocedure w inated insect water. The Recovery c , ng/m') arc < range hardly find distilled RESULTS AND DISCUSSION | peaks on the These peaks Development of Column Material. The most critical poir; both the GC in this investigation was to develop the best composition r really arc Bf the filter material, both with regards to absorption and ir These peaks t desorption. a very small t In addition to the column materials mentioned in Table! to distilled w two others were tested (5, 6). Amberlite XAD-2 a croc- out any water linked non-ionic copolymer of styrene and divinylbenzee, The identi: absorbed the chlorinated hydrocarbons from the water witi amount prese high efficiency but the desorption from the filter was not of the 14 pcai very easy. From Porapak, 100-120 mesh, with a simik pesticides ev composition as Amberlite, some pesticides could be elute; i system. Thi with recoveries over 50%, but impurities in the support we; of DDE and very difficult to remove. amounts wer As shown in Table I, Chromosorb W, 60-80 mesh, coverrij in this case with a mixture of Carbowax 4000 monostcarate and rt-undc I chromatograi cane gave good results, while any of them alone gave to); recoveries for the pesticides used. When the amount ff undecane was higher than 25-30 grams per 100 grams # solid support, it ran out of the filter during the filtration pro cedure and the filter material was difficult to handle. Besides Chromosorb W, Chromosorb P, 35-80 mesh, tk Sampif Silica gel HMDS-ireated, 50-72 mesh, were tried. The* Tap water materials could not maintain the necessary amount of statioo Incoming war ary phase to give a satisfactory recovery. Waste water v No diminished recovery could be seen after increasing th-j sediment waterflow through the filter from 65 to 130 ml per minute, bt | if the amount of filter material was doubled from 2 to - j Sediment Waste water v red i men l grama, the recovery waa increased. With 4 grams, however' Analysis cond Filler: 3 g Flow speed (6) W. A. Win*ten. Anal. Chcm., 34, 1334 (1962). 14*4 . ANALYTICAL CHEMISTRY, VOL. 42, NO. 13, NOVEMBER 1970 DSW 332451 STLCOPCB4079027 ; ml of water [ iher waters : I separately I ; uch waters, : I and after gnd passed ntinued for to elute the a graduated : epared and recipitatioa. ; is extracted In X 1 cm) ;i is collected taken. The r ;>W. | aphy. One ! o containing 1 i overed with ' fuged. The Fnre la. Gas chromatogram from SF 96 rnhaaa of extract from distilled water b. Gas chrosMtogram from SF 96 columa of extract flrom mlural water ; \ide ice and her, a 10-id it was difficult to reach the 63 ml/min necessary to give 100 the injection :entrated to ied nitrogen liters in 24 hours. Recovery Experiments. The efficiency of the over-all procedure was tested by adding known amounts of chlor t is injected ;hcr of these uted hydro- i-i, however. inated insecticides or polychlorinated biphenyl (PCB) to the water. The recoveries are found in Table I. Recoveryexperiments at the ppq-level (parts per quadrillion, ag/m*) are difficult to verify, because a true blank in this range hardly exists. For instance, it was impossible to find distilled water to fortify because the water itself gave Figure 2. Gas chromatogram from SF 96 column of extract peaks on the gas chromatograph in this method (Figure la). from sewage sludge These peaks most often correspond to BHC and lindane on ritical point both the GC columns. Where they come from, and if they solutions (Chophen A 40 and A 50, Bayer). Because of the nposition of really are BHC and lihdane has not been further examined. thorough clean up with sulfuric add, all epoxy-containing tipn and to These peaks are responsible for the recoveries over 100% when pesticides, such as dieldrin, will be destroyed. This method a very small amount (180 ppq or lower) of standard is added can be justified because epoxy-containing pestiddes are very 11 in Table I, to distilled water. A blank made by elution of the filter with rare in Sweden. '>-2 a cross- out any water passing through was totally free from peaks. Seasitivtty. With a range setting of */ of highest sensitivity, inylbenzene The identification of the peaks and the calculation of the 10 ng/m* of lindane can be detected if the size of the sample is : water with amount present became very difficult because peaks from some 200 liters, the extract is concentrated to 2 ml and 10 n\ is ter was not of the 14 peaks of PCB overlapped those from the chlorinated h a similar pesticides even when using the mentioned d6uble/ column iqjected. Results from Analyses of Water. Natural and tap water d be eluted 'jstem. This made it impossible to get a true calculation upport were of DDE and DDD in the waste waters even when detectable from the water-works in Lovd on Lake M&Iaren taken April -24 and 22,1968, were analyzed for the presence of BHC, lin amounts were present The calculation of PCB is possible dane, aldrin, DDE, DDD, DDT, and PCB (Figure 1b shows esh, covered is this case because of the similarity between the sample the chromatogram from natural water). Table II shows that and n-unde- chromatogram and diromatograms from known standards the values are of the same magnitude in both samples. le gave bad amount of X) grann of lirution pro ii Table II. CMorinated llydrocarbans In Tap- aad Waste Waters le. ) mesh, and ried. These it of station Sample Tip water taming water Sempiing date 22/4/68 ,24/4/68 Sampling Place Lovi LovO Water L 176 164 Sedisent. g BHC 0.03 0.12 I inAM 0.07 0.16 ng per kg water, ppt DDE DDD 0.07 0.06 0.22 0.24 DDT 0 0.33 Waste water without ereasing the odunent 24/4/68 Henriktdal 10 22 38 minute, but I Sediment 24/4/68 Henriksdal 2.63 38 146 Present rom 2 to 4 J Watte water with sediment is, however. ) 24/4/68 Henrikadal 10 2.65 60 184 100 .100 Aaalym conditions for water analyses: fiber: 3 g 10-30 (10% Carbowax, 30% undecane on Chrotnosorb W). fimrspeed: 63ml/mia. DSW 332452 PCB 0.33 0.30 1330 * 1330 ANALYTICAL CHEMISTRY. VOL. 42, NO. 13. NOVEMBER 1970 14B5 STLCOPCB4079028 Waste water leaving the purification plant in Hcnriksdal followed by elution with hexane from a silica gel colurns * near Stockholm was analyzed April 24, 1968. The sediment did not remove the artifacts from the chlorinated hydrocarbo* j Slntinr and the water were analyzed separately as described above. fraction. of mdI in The results, given in Table II, show that the water itself was When treating the extract with potassium hydroxide k | tempernti almost free from residues in relation to the amount Found in methanol, the artifacts disappeared. Analysis of highly cos-' This In-11 the aluminium sulfate sediment, indicating the good effect if ccntrated extract on a combined gas chromatograph max dsnrplin the plant used the aluminium sulfate precipitation in the dean* spectrometer (LK B 7 000) did not give any result. When tha | in the vt ing procedure. The weight of sediment plus aluminium hy extract was cooled in carbon dioxide ice, crystals appeared tcmpiTiiti droxide was 26S mg per liter of water. which could be analyzed on the mass spectrometer (tia the type of sj A sample of 10 liters of waste water taken April 16 was im direct inlet) and shown to be elemental sulfur as S, molecule* recently d possible to analyze because serious artifacts were present. Finally the three artifact peaks appeared on the gas chromato. region th The amount of the artifacts was so large that the 10-ml ex graphwhen a sulfur solution was injected giving proof th phase to tract from the water bad to be diluted 100 times to give peaks sulfur was responsible for these peaks. ! over span with the same height as 0.1 ng of aldrin. In the same way the extract from one-fifth or 0.6 gram of the solid had to be diluted ACKNOWLEDGMENT i ary phasi and widcl to 1500 ml to give the peak height corresponding to 0.1 ng of aldrin. The artifacts gave three peaks, (see Figure 2, peaks X, K, and Z) with the last peak having a retention time almost equal to aldrin on the SF 96 column and exactly equal to lin The authors gratefully acknowledge the help of Professr G. Widmark, the bead of the analytical institute at the U versity of Stockholm, and civil engineer B. Nucci. invest igut ately cho; but also a To illus daneon theQFI column. Anacetonitril/n-hexanepartition (7) compositi (7) IL W. Ssntrhwr and P. A. MBs, J. Ass. Ogke Agr. Chemists, tt, II (1966). Rbczivid for review March 9, 1970. Accepted July H 1970. compositi of a close Xt mole ` plete soli< melt, yiel JT,. Thu: with respt peratures, Variable Selectivity Stationary Phases for Gas Chromatography correspon curve. W I melted to Raymond Annino and P. F. McCrea I Research Center, The Foxboro Company, Foxboro, Mass. DSW 332453 Xt. Ther greater so; than subsi A and B a; I |! Tha parformanca of a naw class of chromatographic stationary phasas is described. Their selectivity can ba manipulated over a wide range merely by changing the column temperature. By combining substancos differing in molting point and solute selectivity, a stationary phase mixture la produced exhibiting an extended rang# of molting. Since both the effective volume and composition of the melt are strongly temperature dependent, absolute and relative reten tion volumes of the solutes are altered markedly by temperature over tha transition region, resulting In varying degrees of specificity through choico of the appropriate column temperature. Positive relative retention shifts on the order of 100% have boon ob served with a 20 *C increase in temperature. It is For quantitative analysis, the separation of complex mixture has been accomplished by combining different station^ phases either as series columns or in a single column (3-5). All of these methods reflect a need foe a stationary phm whose selectivity can be varied over a large range by maripvj lating some convenient parameter such as the column tea perature. A recently reported method for peak idenUficstie; (5) relies on variations in the temperature dependence* of ti, Kovats Indices (7) for various classes of solutes. Tfe; changes in selectivity with temperature, however, are relathe. __ small for conventional stationary phases. This paper describes a class of stationary phases was traver iciectivitie ranging in A conse lemperatui the coiumi lion range 7i, there is retention n surface. \ rapidly bee for all soli r,, positive I shown that the ability of the novel stationary phase to Identify various classes of solutes by a retention Index method is as good as the two-column method, and possesses the additional advantage that its specificity can be varied at will to obtain tha best resolution of a complex sample. undergo reversible temperature-dependent composition, changes to produce large variations in selectivity for variotj the increas classes of solutes. These systems are not to be confused ' compositio and volum the use of liquid crystals (8) or conventional liquid korbai operated near their freezing point (9), where alteration retention a.' The mair selectivity for different solutes can be attributed primarily to: fi is the re A number or gas chrometographic procedures have been change in the physical state of the solvent. : compositio, devised which owe their success to the use of two different *nce. Ho\ stationary phases, either singly or in combination. For example, a widely uaed technique for solute identtfication has been the determination of retention behavior of the un known sample on two columns of different aelectivity (I, 2). (3) R. A. Keller and G. H. Stewart, Anal. Cmm., 36,1186 (1W . imitation. (4) G. P. Hildebrand and C. N. Reilley, Ibid., p 47. ' ,(5) A. B. Littlewood and F. W. Willmott, ibid., 38, 1031 (19W1 The ther (6) N. G Saha and G. D. Mitra, J. Ckromatogr. Set., 8 84 (191 j Phases was (7) E, Kovats, in "Advances in ChromatographyVoL 1, i-y (1) D. A. Leathard and B. C Shurtock, in "Progress in Gas Chro Giddings and R. A Keller, Ed.. M. Dekker, flew Yet*. H ' HO) J. H. P, r matography,** J. H. Purnell, Ed., Interacacnoe, New York, N. Y.. 190, pp 18,23. (2) G. Schomburg, in "Advances in Chromatography,** VoL 6. J. C GHiding* and E. A KeUer. Ed., M. pekksr. New York, N. Y., 1968, P 211. 1963. ._ (8) H. Kelkcr and E. Von Schivizhoffen, in "Advances Or matography," VoL 6. J. G Giddings and R. A Kdlet. I M. Dekker, New York, N. Y., 1968, p 347. (9) R. Oaeyi and H. Freund, J. Oat Ckromatogr., 6, 421 (lw Sri. Hunt;. nD P. F. N>12) p. f. r (1969). * * ~* * w'M An Kirs 1 *5 (dAUCU RPP 1QTO STLCOPCB4079029