Atomic Absorption Spectrometry with by ujl89480

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									                                                                  Clinical Chemistry     42, No. 8, 1996                                                               1287




Traces     of Cadmium       in Human       Scalp Hair Measured       by                   (Barcelona,       Spain) was used to suspend the slurry particles just
Electrothermal      Atomic Absorption Spectrometry with the                               before measurements.
Slurry Sampling       Technique,      Pilar Bermejo-Barrera, * Antonio                        All solutions        were prepared          from analytical       reagent-grade
Moreda-Pi#{241}eiro,Teresa Romero-Barbeito,     Jorge Moreda-Pi#{241}eiro,                chemicals       with ultrapure         water, resistivity       18 M[I/cm        (Milli-
and Adela Bermejo-Barrera        (Dept. of Anal. Chem., Nutrition,                        pore, Bedford, MA). Acetone was from Carlo Erba Analyticabs,
and Bromatob., Faculty of Chem., Univ. of Santiago de Com-                                Milan, Italy; cadmium nitrate stock calibration                     solution,     1 gIL,
posteba, Av. das Ciencias s/n, E - 15706 Santiago de Compostela,                          from BDH, Poole, UK diammonium                         hydrogen phosphate stock
Spain; *author for correspondence:          fax 34 81 595012, e-mail                      calibration      solution,      20 gIL, prepared          from diammonium            hy-
qnl956@usc.es)                                                                            drogen phosphate,             was from Scharlau, Barcelona,              Spain; glyc-
                                                                                          erol was from Sigma Chemical Co., St. Louis, MO; lanthanum
Cadmium        induces toxic effects in humans, even at low concen-                       chloride stock calibration             solution,      1 g/L, prepared       from ban-
trations, and is concentrated             in specific organs [1]. Blood and               thanum chloride, was from Merck, Darmstadt,                         Germany;       mag-
urine samples are most often used to assess cadmium burden in                             nesium nitrate stock calibration               solution, 2 g/L, prepared from
humans [1]. Hair analysis has also been used for measurement                        of    magnesium          nitrate, was from BDH; and nitric acid, 350 g/L,
nutritional      deficiencies     [2, 3], for biological       monitoring      [4, 5],    prepared from nitric acid Anabar, 69.0-70.5%                       with a maximum
and as an index of environmental               exposure [6, 7]. Hair is readly            cadmium        content of 0.005 mgIL, was from BDH. Palladium
available and easily collected, shipped, stored, and handled, and                         stock calibration           solution,    3 g/L, was prepared           by dissolving
it can be obtained with little or no pain [7]. In addition, trace                         powdered        palladium        (Aldrich Chemicals,           Milwaukee,       WI) in
element      concentrations         in hair are -10-fold          greater than in         concentrated         nitric acid. Reference Material CRM 397, human
blood or urine /7-9].                                                                     hair, was from the Commission                       of European        Communities
    Sample decomposition               procedures      for hair [3, 10, 11] are           Community           Bureau of Reference            (BCR), with a certified cad-
often tedious and time consuming                  and allow the possibility         of    mium content of 0.521 ± 0.024 tg/g.                      Triton X-b00 was from
sample      contamination          and loss of volatile          metals,    such as       Merck, and Viscalex HV3O from Allied Colboids, Bradford, UK.
cadmium.         Electrothermal          atomic     absorption       spectrometry              Approximately         0.5 g of hair was cut with stainless steel scissors
(ETAAS) allows the determination                 of metals in solid samples by            from the scalp region [5]. The samples were washed as proposed
introducing       the sample as a slurry [12], so the problems related                    by the International           Atomic Energy Agency [15], beginning with
to conventional         sample decomposition           procedures      are avoided.       ultrapure      water, three washes with acetone, and three washes
In our experience [13, 14], results of ETAAS methods based on                             with ultrapure          water. The samples were oven-dried                  at 100 #{176}C
the slurry sampling are comparable                      with the conventional             and kept in polyethylene              containers.
wet-digestion        sample pretreatments.           Among the problems             of         The washed hair samples were pulverized for 20 mm at 75%
ETAAS is the high background                   signal seen with poor matrix               power and sieved to achieve a particle size <125 j.m. We
volatilizations,      especially when low charring temperatures                  must     combined 0.1 g of the hair powder and 1 mL of ultrapure water
be used for volatile elements such as cadmium.                      This problem          in a polyethylene            vial (Zinsser Analytic, Frankfurt,             Germany)
can be addressed            by use of the Zeeman              effect background           with gentle shaking to suspend the hair particles. The slurry was
correction.      We developed a slurry sampbing-ETAAS                    method for       adjusted to a final volume of 25 mL by addition of ultrapure
measuring        cadmium       in human scalp hair using D2 arc back-                     water. By laser diffraction             the mean particle size was 0.8 j.tm.
ground correction          and (NH4),HPO4            as chemical modifier.                The hair slurries were kept in polyethylene                     vials at 4 #{176}C.
    We used a Perkin-Ebmer                   (Norwalk,      CT) Model          1 lOOB          A 700-pt        portion of the slurry with appropiate                 volumes of
 atomic absorption           spectrometer       equipped      with a deuterium             diammonium           hydrogen phosphate            and glycerol solutions added
 lamp, a HGA-400             graphite     furnace atomizer,        and an AS-40            to give concentrations             of 2 g/L and 4 g/L, respectively,                was
autosampler.        Spectrometric        operating     conditions     are given in         transferred      into an autosampler           cup, then diluted to I mL, and
Table      1. A Laser Coulter            Series LS100 Fraunhofer             Optical       stirred magnetically           before measurements.           We injected 20 jiL
Model particle sizer (Coulter Electronics,                Hiabeah, FL) was used            into the atomizer and used the sequentialdry-char-atomize-
 to obtain the particle size distribution.              A vibrational      mill ball,      clean program of the graphite furnace (Table I). The integrated
 Retsch (Haan, Germany)              ISO-900 1 equipped with zirconia cups                 absorbance       was recorded.
 (1.5 mL in size) and zirconia balls (7 mm diameter), was used to                              The ETAAS conditions were optimized for an aqueous Cd2 +
 pulverize samples and to reduce the particle size of the pow-                             solution (1 .tg/L) and a hair slurry with 0.2 g/L of added Cd2 ±
 dered hair samples. An Agimatic magnetic agitator from Selecta                            with palladium,          magnesium        nitrate, palladium-magnesium               ni-
                                                                                           trate, diammonium             hydrogen     phosphate,       and lanthanum-nitric
                                                                                           acid as chemical modifiers.              The highest charring           temperature
      Table 1. GraphIte furnace temperature program and                                    was achieved with the use of diammonium                      hydrogen phosphate,
                                                                                                       for
                                                                                           900 #{176}C, hair slurries and aqueous cadmium solutions. The
                  spectrometer        operating      conditions.
                                                                                           background         signal at this temperature,           -0.02 3, was lower than
                  Temperature,        Ramp time,        Hold time,      Ar flow-rate,
    Stage                                   $                S            mL/min           for the other chemical               modifiers      at their optimum          charring
                                                                                           temperatures.         Other variables of the graphite furnace tempera-
Drying                  150                15               20              300
                                                                                           ture program are given in Table 1.
Charring                900                10               10              300
                                                                                               The calibration          was linear over the range 0.06-1.00                  J.Lg/L
Atomization            2200                     1             2          0 (Read)
                                                                                           Cd2 . The standard addition method was used over this same
Cleaning               2500                     1             3            300
                                                                                           range of concentration.             Each cadmium concentration               was mea-
  Conditions: Cd hollow cathode lamp (4 mA): wavelength, 228.8 nm: spectral                sured four times,the correlation                                 of
                                                                                                                                            coefficients the calibration
bandwidth. 0.7 nm: integration time. 3 s: peak-areameasurements: 02 lamp                   (A, = -0.002          + 0.074 [Cdl)and standardaddition(A = 0.0 18
backgroundcorrector: injection volume, 20 xL: pyrolytic graphite tubes.                     + 0.102 [Cd]) curves being 0.9999 and 0.9997, respectively,
1288                                                                            Technical   Briefs




where A, is integrated            absorbance       and [Cd] is in j.g/L. The                    variations in trace-metal concentrations in hair. din Chem 1982:
                                                                                                28:2411-3.
standard errors of the intercept              were 0.002 and 0.003 and the                   7. Bunguena JL, Bunguena M, RondOn CE, Rivas C, Burguena JA, AlancOn OM.
standard     errors of the slope were 0.004 and 0.006 for the                                   Determination of lead in hair of exposed gas station workers and in
calibration      and standard         addition      curves, respectively.        The            unexposed adults by microwave-aided dissolution of samples and flow
                                                                                                injection/atomic absorption spectronetry. J Trace Elem Electrolytes Health
calibration     and standard addition slopes are statistically                differ-
                                                                                                Dis 1987:1:21-6.
ent, with F- and t-tests confidence              levels of 99.5% [16]. There-                8. Rivlin RS. Misuse of hair analysis for nutritional assessment. Am J Med
fore, matrix effect is important               and standard      addition graphs                1983:75:489-93.
must be used.                                                                                9. Capel ID, Pinnok MH, Donell HM, Williams DC, Grant ECG.Comparisonof
                                                                                                   concentrations of some trace, bulk, and toxic metals in the hair of normal
    We studied the limit of detection (LOD = 3 SD/m) and the                                       and dyslexic children. dIm Chem 1981:27:879-81.
limit of quantification          (LOQ = 10 SD/m), where SD is the                           10.    Voellkopf U, Gnobenski Z. Interference in the analysis of biological samples
standard deviation of 11 measurements                   of a blank and m is the                    using the stabilized temperature platform furnace and Zeeman background
                                                                                                   correction. At Spectnosc 1984:5:115-22.
slope of the standard addition graph. The LOD and LOQ were
                                                                                            11.    Ebdon L, Fisher AS, Hill S. Use of onganophosphonus vapours as chemical
22.5 and 74.9 tg/kg, respectively.                                                                 modifiers for the detenmination of cadmium by electrothermal atomic
   The within-run        precision (n = 11) CVs for low, normal, and                               absorption spectrometny. J Anal At Spectrom 1992:7:511-3.
above-normal        concentrations        were 6.9%, 4.2% and 2.5%, re-                     1.2.   Bendicho C, De Loos-Vollebregt M. Solid sampling in electrothermal atomic
                                                                                                   absorption spectrometry using commercial atomizer. J Anal At Spectrom
spectively. The intraassay CV for four determinations                     was 3.8%                 1991:6:353-74.
at a cadmium concentration              of 0.08 g/g.       The total SD (slurry             13.    Bermejo-BarnenaP. Aboal-Somoza M, Soto-Fenreiro RM, Dominguez-Gonzalez
preparation       and ETAAS            measurement)        calculated      from 11                 R. Palladium-magnesium nitrate as a chemical modifier for the determina-
                                                                                                   tion oflead in mussel slurries by electrothermal atomic absorption spec-
different    slurries   prepared        from the same hair sample, the                             tnometry.Analyst 1993:118:665-8.
cadmium concentration              being determined         in each slurry twice            14.                                                     M,             A.
                                                                                                   Bermejo-Barrena P. Lorenzo-Alonso Mi, Aboal-Somoza Benmejo-Barnena
over 2 weeks, was 6.9%. The analytical recoveries (n = 11) of                                   Determination of arsenic in mussels by slurry sampling and electrothermal
                                                                                                atomic absorption spectrometry (ETAAS). Miknochim Acta 1994:117:49-
cadmium added to the hair slurry at concentrations                   of 0.25, 0.50,             64.
and 1.00 g/L          were 101.0% ± 3.3%,                102.0%     ± 2.4%,       and       15. Report on the Second Research Coordination Meeting of IAEA, Neuherberg,
100.0%      ±     1.4%, respectively.           For CRM 397 human                hair              Germany,October1985.
Reference Material with a certified cadmium content of 0.521 ±                              16.    Miller IC, Miller iN. Statistics for analytical chemistry. Significance tests.
                                                                                                   NewYork: Wiley, 1984:52-79.
                 we
0.024 .tg/g, obtaineda 99.5% confidenceinterval f 0.533 ±               o                   17.    Takagi Y, Matsuda S. Ohmori Y, Masuda T, Vinson JA, Mehra MC, et al.
0.015 .tg/g (mean ± t SD/n21,                  where n = 11 determinations                         Trace elements in human hair: an international comparison. Bull Environ
and t is the Student’s         t-value     [16] for n - 1 = 10 degrees of                       ContamToxicol1986:48:27-32.
                                                                                            18. Srikuman TS, Ockerman PA, Akesson B. Trace element status in vegetarians
freedom). To study the influence of the slurry concentration                       on              from southern India. Nuts Res 1992:12:187-98.
the precision and analytical recovery of the method, we prepared                            19. lyengar V. Woittiez J. Trace elements in human specimens: evaluation of
slurries that contained 2, 3, 4, 8, and 12 g/L hair, corresponding                                 literature data to identify reference values. Clin Chem 1988:34:474-81.
to 0.05, 0.07 5, 0.1, 0.2, and 0.4 g of sample, respectively.                    The
CVs (n = 11) were <2.5% for all slurry concentrations                        and the
analytical recoveries were 97.0% ± 3.1% to 103.0% ± 2.3% for
all slurry concentrations           and for the two cadmium concentra-
tions tested (0.5 and 1.0 j.tg/L).                                                          A Case of Imniunogbobulin            A-A Conjugated       with Lactate
   We found no interferences                 from the following          species at          Dehydrogenase-5      Isoenzyme,       Causing   an Extremely       High
concentrations       of 1 mg/L: Ag, M,               AS3,     Ba2, Ca2, Co2,                 Enzyme Activity in Serum, Minoru Tozuka,” Hiroya Hidaka,2
Cr,      Cu2,     Fe3, K, Mg2,              Mn2,      Ni2,     Pb2, Se2, Sn2,                Nobuo Okumura,      Tetrurokhikawa,’ KenichiFurihata,2         and Tm-
Sr2, Zn2,         Br, C1, I, S042,                and Si032.                                 tomu Katsuyama2 (tDiv. of Clin. Pathol., Nagano              Children’s
    In 13 scalp hair samples, the cadmium concentrations                        were         Hosp., 3100 Toyoshina,       Minami-Azumi,      Nagano     399-82, Ja-
0.02-0.19      g/g.    Reported        cadmium values were 0.3 zg/g for                      pan, and 2Centrab Clin. Labs. and ‘School of Allied Med. Sci.,
healthy people from Europe (Poland and Sweden) [3, 17, 18],                                  Shinshu Univ. Hosp., 3-1-1 Asahi, Matsumoto,             Nagano      390,
0.5-1.5 j.g/g for North Americans                  (Canada and US) [17, 19],                Japan;  *author  for correspondence:      fax 81-263-73-5432)
and 0.3 jig/g for Japanese [17]. The cadmium content in human
hair is rebated to food intake. Study of the possible correlation                           There      have    been    numerous       reports    on   abnormal      isoenzyme
between cadmium in hair and in other samples such as blood and                              patterns    of plasma lactate dehydrogenase          (LD; EC 1.1.1.27)
urine is needed [3].                                                                        [l-7J. In many of these reports, the LD isoenzymes               formed
                                                                                            complexes     with either IgA [1-5] or IgG [6, 7]. Moderately
References                                                                                  increased    LD activities were observed in many patients with
 1.   TsalevDL. Atomic absorptionspectrometnyoccupationaland environmental                  immunogbobulmn-bound          LD [1, 3, 6]. The increased LD activity
      health practice, Vol. II. Biological and toxicological characteristics of individ-
                                                                                            is thought to be caused by antibody binding to serum LD and
      ual elements. Boca Raton, FL:CRCPress, 1984:105-11.
 2. Lamand M, FavienA, Pineau A. La determination des oligoelements dans lea                interfering   with the reticuboendotheliab     system clearance of LD
    poils et dans les cheveux: int#{233}r#{233}t Ann Biol Clin 1990:48:433-42.
                                       et limites.                                          [8].
 3. Srikuman TS, Kallgard A, Lindebeng S. Ockerman PA, Akesson BJ. Tnace                       LD-IgG      complexes     are generally   characterized   by the in-
    elements concentrations In ham of subjects from two South Pacific islands,
                                                                                            volvement of all five LD isoenzymes.         Most LD-IgA complexes
    Atafu (Tokelau) and Kitava (Papua New Guinea). J Trace Elem Electrolytes
    Health Dis 1994:8:21-6.                                                                 involve the LD3 isoenzyme           [2] or both the LD2 and LD3
 4. Held NA, Buergel N, Wilson CA, Monsen ER.Constancyof zinc and copper                    isoenzymes      [2, 3], although   some cases involve all five LD
      status in adult women consuming diets varying in ascorbic and phytate                 isoenzymes     [9]. Three kinds of binding specificities      have been
      content. NutnRep mt 1988:37:1307-16.
 5. Bencze K. What contribution can be made to biological monitoring by hair
                                                                                            suggested for immunogbobulmns conjugated with LD [4-6]: (a)
      analysis. Fresenius J Anal Chem 1990:338:58-61.                                       immunoglobulins        that react with either the H or the M subunit
 6. De AntonioSM, Katz SA, Schemer DM, Wood JD. Anatomically related                        and bind LDI-LD4           or LD2-LD5,      respectively;  (b) immuno-

								
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