Document 6R2wmEzLQgMvg1xQaN14eaKJg

ji i^^kafaiiiiB^ai^r-awLii/. THE DETERMINATION OF CERTAIN TOXICOLOGICAL TRACE METALS 8Y ATOMIC ADSORPTION SPECTROPHOTOMETRY* ttotlrr Sluvtit <nd ScWna Sprague Prritin-Elmer Corporation Sprualk. Connecticut .= 1 and Fredric Riders and V. Catdeim Wed cal Eroainer'x Office Philadelphia, Pemsyh'anla 0 i Atomic absorption apectropbotometry provide* a Dnai to detennine the concentration of net*!* at their natural Irvela in biological media with a minimum of sample preparation, and la tone catra. with no sample preparation at all. The net bod i* already routine in many efiairai laboratorieafor tbe decemination of magnesium, calcium, potaaaium and sodium ia blood and urine. For urine determine! too a dilution alone ia required, however, in tbe determination of blood, it baa proven uaeful in some caaea to drproteiniie aerum prior to making an aaalyaia. Method* have been described (1) for determining lead, mercury, bismuth, cadmitan, line, and nickel ia urine by atomic absorption spectrophotometry using organic extraction to concen trate the metals. Zinc and calcium ran be detereieed directly ia urine sample*. New method* O have made it possible to extend tbe senaitivity of atomic absorption technique* so that snore of the metals of interest can be determined by direct analysiaof unne and deproteinixed blood In addition to tbe determination of zinc and cadmium in urine, theae new technique* have made it posiiblr to determine manganese, chromium, cadnium, copper, nod molybdenum ia blood at level* lower than 1 ppm (3). Thia paper consider* a group of metal* of toxicological interest. Urine samples wet* determined directly, and blood samples were deproteinixed with nitric acid. ATOMIC ADSORPTION ANALYTICAL METHOD (Vise and blood sample* are determined by atomic absorption by burning the sample ia as air-acetylene flame. Standard* of the metal of interest In simple aqueous solutions are also burned, and the resulting absorption is plotted against concentration. Tbe concentration of metal ia the unknown samples ia then read from thia working curve. Presented at the American Arndemy ofForenaic Sciences, Chicago, February, 1963. ii'smaw.i enw-w." iryWi -.IB*-11 ma p pa* > LI A11543 kMl C4 - O Tl C* Pt Um,\ tUc4 wt\n% fcl4 vri*4 Moo4 *'** wt*>* vtln* TAILC ( M.h I A444 (**) (Monk) 04 04 045 (VorA) 04 0.8 M (W**) 0 006 00} 0.15 (Wnk) 0.006 0.0} 048 (Monk) 040 0.90 045 (Wank) 04 0.9 1.1 (blvik) 04 14 0.8 (*) 10 10 1.0 M*l P4 (ppa) Br A-A Br Ckm. 0015 001 0.015 <0.01 0.53 059 0.76 083 001 0.03 044 0.38 081 0.83 1.77 1.66 0.13 0.10 0.04 0.08 --. 009 0.14 0.13 0.19 0.06 001 003 041 0.03 047 0.43 <0.1 <0.01 043 0.57 0.75 0.84 0.27 0.30 03 ' 0.1 0.3 023 0.9 0.9 3.0 1.1 <0.1 <0.1 0.4 01 04 04 0.7 04 <0.3 04 14 13 14 0.9 01 1.3 , ^umjwmwxf}ynynBfiiptf t-iiJWJ1JllJJJ fJI'JJ i' }A[^ tgM?.yj.|j|!. I'ggyw^yNj j ui*.t^iF.q.j BBWjwy.pwi tm iiiiB iy r 1" *>imwi; iff * w w w r o w t r. I^ .wear.1 ip>. iiyjpwiw^npi wms&m LIA11544 i t'rViWMriifM^--niirni u'. L'ii. A very small concentration of a metal will produce * large signal when scale ex pansion I* used, but (hr limit of detection for escb element ia determined by the recorded noise level. Some metal* can l>e determined at their natural level in urine and blood, while many other* can be determined at lexicologically significant fevrla. Improved instrument componenta will re duce the detection llmita for many metals. EXPERIMENTAL RESULTS Sample* of urine and blood containing known amounts of cadmium, chromium, thallium, . i cobalt, and lead were prepared by the Philadelphia Medical Examiner' Office. Portion* of each i ample * ere determined both by atomic absorption and by conventional chemical method*. The reaulta of these analyaea are shown ia Table I. In each case a blank of unapiked solution was also determined. The agreement of the atomic absorption determination* ia at least as good a* that obtained by tbe chemical method, the analytical time required waa very much lea*, and only a amalt aample waa needed. ; ; The preparation of the working curve take* about ten minutea per element, and tbe un known aample* are burned for about 30 aeoooda in tbe flame. Ten unknown sample* can be com pleted in teas than half an hour. The only requirement ii that the aample be sufficiently nonviacousto allow aspiration into the flame at the same rate a* tbe standard*. Natural urine sample* meet this requirement, but blood or tissue alurriea are too viscous. Blood samples need only be treated with an equal volume of warm nitric acid for atomic absorption analyst*. The atomic absorption determinations show* in Table I each required about 2 to A mi of urine or blood. SAMPLE PREPARATION - MATERIALS 1. Poolrd citrated, banked blood. 2. Pooled, normal urine. 3. A^ieou* stock solutions of 3fdSO(. 811 jO, SajCiO^.llIjO, Co (NOj) j.6llj0. Pb (SOj )j *nd T1SO, containing the equivalent of I mg of the respective metal per ml. 4. Biological stock solutions: 1 ml of aqurou* met.,! slock solution per 100 ml blood oe urine. The individual sample* were prepared by tniaing appropriate proportions of biological stock solution and pooled biological material to obtain final volume* of 50 ml for urine and 25 ml (or blood For the atomic absorption analysis of the urine sample*. 6 ml aliquot*, to which 0 1 od UNO, had been added, were used The remaining i! ml urine aliquots were analysed chemical ly. The Mood ssople* were prrj>#red for at<>mir absorption sprrtrophotometry by nddng 3 ml IINOj In a ) ml aliquot of blood in a vial The vial waa tte-n dosed andwsfmedon a hot water bath tot 2 hours to dissolve the blood In the IINOj The chemical analyse* were performed on 20 ml of -j the remainder of the blood samples. 9 LI A11545 fWBtptPMi CHEMICAL ANALYSIS The specimens were digested with HNOj, H}S04. and IICI04 acids (5) for the deter minations of cwhnium, cot-alt, lead and thallium. For chromium determination! the specimens were digested with perchloric acid (6). Dithizone methods were u*ed for lead (7) and for cadmium (8, 9). chromium was determined with S-diphenyl cart-an dr (10), cobalt with nitroao-R-all (11). andthallium with methyl violet (12). The following personnel time periods are required for the chemical analyses of individual samples, not including reagent ptepsratioe. ,, 1. Digestions I1N0,-H/S04-Ha04 method; 12 minutes Iia04 method; 8 minutes 2. Analysis of digest Cadmium: I < minutes chromium 9 minutes Cobalt: 19minutes Lead: Thallium: 23 minutes IS minutes msojsgoN The develtvjunenl of atomic abvorprion techniques for toxicological analyses will be rontmued and extended. The detre lion lnr.it> for < oball anJ lead will be lowered by the y*e of lu-tter hollow c at)>-dr ftnun e> Te< hniqyrv will he devefojvrd that will enable atomic absorption to measure toxicological concentration* of mercury andaelenium. 1 %rt* ntriHod* (\) should make it po**it4r to drtrttntn* beryllium o at tl* \try Jow t-onernlf(i<>n that afr* darr.ajcirif to biolnffiral ylrmv I Jtimatrly, atomic absorption about d provide tbrrorari* to <fetrmifw ail themriaN ofloiirolojrtca] inl^/rat with VfTjr little ample prrpvatif*). with amall total aampfe, and io only a few oiinutra frf analysis. REFERENCES 1. J.I1. Anal. Omi*, \i. 614 U%2). 2. H I.. KI>n md V Matin. Af>plird Optic * 2, WI <I%U t .1. 0.0. (Vf4hin*E|mrf \rw*fett#*f No, 11, M afrit 196X 4. R, Matin and 0.0, Vanning, Anal. (-hr at. 3A, 2T>3 (1963), ?1, F. KwpintWl, E*. Hirifeft, IX (,,f,K. J, (VdiatH< .* 42, 687 (I9S3E 6. J.F. (ioodw.h, A.J, IUIh , J, l.*u. Clm. 1M. Yb ). 7, E\ Hirtfefa, n,(i, |>ufifth|(i*rft( H. (Utr/ef, |fn|, M'M. and Suf|frry 1 VS (1955)* 8 H E. Ilumhtf.^ (Itrfefi-r), Afcwf, (I***!. i4 (utl* Iftdttats II)((irtiiMa, 9. H.E. Sall/maa, Ar.-I. CKrt*. 491 UWl). 10. (Ml. Qi.^a h . II J C.UMia. |.fllwn. Ahl, Oir*a, 11, E.0, Paflmd-f, N, \#*I%4n, A, l.aritn, V. Ku*tncf, )> Amrt, |nduj. Jly/f. A*or. 20. 4S3(IVj 9J. i;. E.E.Cam,4-dl, V F. Vittitfr^n* j.A. Eint*>. J. Amrf, Mu-t, ll>*. Aaw.JjO. M (im 10 jgjljww j Ia^MTijlasgfia. n,1111WJ y .tn^wr