Rapid determination of lead and cadmium in sewage sludge samples using electrothermal atomic absorption spectrometry with slurry sample introduction

Lead and cadmium concentrations in sewage sludge samples are determined by suspending the ground samples in a solution containing 10% (v/v) concentrated hydrofluoric acid, 1% (v/v) concentrated nitric acid, 0.5% (m/v) dihydrogen ammonium phosphate and 0.1% (m/v) sodium hexametaphosphate. Aliquots of 20 microL of these suspensions (4 mg/mL) are diluted to 1000 microL with the same solution and then injected into the electrothermal atomizer. The drying stage is performed by programming a 400 degrees C temperature, a ramp time of 20 s and a hold time of 15 s on the power supply of the atomizer. No ashing step is used. Platform atomization is carried out at 1600 and 1800 degrees C for Pb and Cd, respectively. Calibration is performed using aqueous standards in the 5-75 and 0.2-5 microg/L Pb and Cd ranges, respectively. Results obtained for three certified reference materials and four samples demonstrate the reliability of the procedures described.     

Rapid determination of lead, cadmium and thallium in cements using electrothermal atomic absorption spectrometry with slurry sample introduction

 A method is proposed for the determination of Pb, Cd and Tl in cements by ETAAS. The samples are suspended in a medium containing 10% v/v ethanol and 1% v/v both conc. nitric and hydrofluoric acids and are directly introduced into the electrothermal atomizer. The drying stage is performed by programming a 400 °C temperature, a ramp time of 5 s and a hold time of 30 s on the power supply to the atomizer. No ashing step is used. Atomization is carried out at 2100, 1800 and 1700 °C for Pb, Cd and Tl, respectively. For Cd determination, ammonium dihydrogen phosphate is added to the suspension medium. No modifier other than hydrofluoric acid is required for the Pb and Tl determination. It is shown that the results obtained by using direct calibration with aqueous standards for five commercial samples agree with those found by means of the standard additions method. Received: 29 March 1996/Revised: 24 May 1996/Accepted: 30 May 1996     

Simultaneous determination of cadmium and lead in wine by electrothermal atomic absorption spectrometry

A method has been developed for the direct simultaneous determination of Cd and Pb in white and red wine by electrothermal atomic absorption spectrometry (ET-AAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior of both analytes during pyrolysis and atomization stages were investigated in 0.028 mol l⁻¹ HNO₃ and in 1+1 v/v diluted wine using mixtures of Pd(NO₃)₂+Mg(NO₃)₂ and NH₄H₂PO₄+Mg(NO₃)₂ as chemical modifiers. With 5 μg Pd+3 μg Mg as the modifiers and a two-step pyrolysis (10 s at 400°C and 10 s at 600°C), the formation of carbonaceous residues inside the atomizer was avoided. For 20 μl of sample (wine+0.056 mol l⁻¹ HNO₃, 1+1, v/v) dispensed into the graphite tube, analytical curves in the 0.10–1.0 μg l⁻¹ Cd and 5.0–50 μg l⁻¹ Pb ranges were established. The characteristic mass was approximately 0.6 pg for Cd and 33 pg for Pb, and the lifetime of the tube was approximately 400 firings. The limits of detection (LOD) based on integrated absorbance (0.03 μg l⁻¹ for Cd, 0.8 μg l⁻¹ for Pb) exceeded the requirements of Brazilian Food Regulations (decree #55871 from Health Department), which establish the maximum permissible level for Cd at 200 μg l⁻¹ and for Pb at 500 μg l⁻¹. The relative standard deviations (n=12) were typically <8% for Cd and <6% for Pb. The recoveries of Cd and Pb added to wine samples varied from 88 to 107% and 93 to 103%, respectively. The accuracy of the direct determination of Cd and Pb was checked for 10 table wines by comparing the results with those obtained for digested wine using single-element ET-AAS, which were in agreement at the 95% confidence level.     

Chemical analysis of manganese nodules. Part I. Determination of seven main and trace constituents after anion-exchange separation

A method is described for the determination of Mn, Cu, Co, Zn, Cd, Pb and U in samples of manganese nodules. After dissolution of the sample in concentrated hydrochloric acid, the elements are adsorbed on a column of the strongly basic anion-exchange resin Dowex 1 from a medium consisting of 50 % (v/v) hexone, 40 % (v/v) isopropanol and 10 % (v/v) 12 M hydrochloric acid. After removal of iron by washing the resin bed with a mixture of the same composition, 6 M hydrochloric acid is passed through the column to elute Mn, Cu, Co, and Pb, and then 1 M hydrochloric acid and 2 M nitric acid to elute Zn, Cd and U. In the eluates the elements are determined by atomic-absorption spectrometry except for uranium which is determined by fluorimetry. The method was used successfully for the determination of mg and p.p.m. quantities of Mn, Cu, Co, Zn, Cd, Pb and U in 17 samples of manganese nodules from the Pacific Ocean.     

Direct determination of lead in sweet fruit-flavored powder drinks by electrothermal atomic absorption spectrometry

A simplified method for direct determination of lead in sweet fruit-flavored powder drinks, syrups and honeys by electrothermal atomic absorption spectrometry without sample digestion is proposed. Samples were dissolved in water, acidified to 0.2% (v/v) HNO₃, and directly injected into an end-capped transversely heated graphite atomizer (THGA). Building up of carbonaceous residue inside the atomizer was effectively precluded for sugar solutions not exceeding 8.0% (m/v) when a heating program with two pyrolysis steps (600 and 1000°C) was carried out without air-ashing. Under these conditions one atomizer supported about 250 firings. Among various chemical modifiers tested, better recovery and repeatability results were obtained with a 5 μg Pd + 3 μg Mg(NO₃)₂ mixture. Tests carried out with individual concomitants containing up to 1.0 μg Na, K, Ca or Cl, and up to 10.0 μg phosphate or sulphate, and several mixtures of these six concomitants, did not reveal significant interferences on lead atomization. Characteristic mass and detection limit based on integrated absorbance were 15 and 11 pg Pb, respectively. The relative standard deviation based on 10 measurements for typical samples (20–60 ng g⁻¹ Pb) was always lower than 5.5%. The detection limit of 7.0 ng g⁻¹ Pb attained the Codex recommendation for the maximum allowed lead contents in the sugar samples. Application of t-test to the results obtained by the proposed direct analysis, and the official method adopted by Food Chemical Codex, demonstrated that there were no significant differences at the 5% probability level.     

Graphite furnace analysis—getting easier and achieving more?

The impact of microwave digestion, hot injection of solutions and chemical modification on the analysis of biological samples by electrothermal atomic absorption spectrometry (AAS) has been assessed. The stabilizing effects of palladium and ruthenium modifiers were compared. Although ruthenium has a higher atom appearance temperature, palladium was the more useful modifier when samples other than water were analysed. When 2 μg of palladium (as PdCl₂) was preconditioned in hydrogen at 500°C, volatile elements were retained at char temperatures up to 1000–1100°C. This allowed similar atomizer programmes to be used for Cd, Cu, Fe, Mn and Pb and accurate determination of these analytes in solutions of reference materials was achieved aqueous standards. Rapid drying of the solutions by hot injection at 120°C reduced the programme time to just over 1 min. A combination of microwave digestion, hot injection of 40% (w/v) HNO₃ solutions and Pd modification produced a rapid and sensitive method for determination of Cd and Pb at sub-μg g^?1 levels in vegetable and protein foodstuffs. Palladium modification also proved useful in simultaneous multi-element determination by continuum source AAS. The picogram detection limits obtained for Cr, Mn and Pb were similar to line source AAS values recorded with the same compromise programme. Accurate determination of Cd, Cr, Cu, Mn, Mo and Pb in NIST SRM 1566 Oyster Tissue indicated the potential of continuum source AAS for multi-element determinations. The advantages of palladium modifications were also illustrated for furnace atomic non-thermal excitation spectrometry (FANES) with a hollow-cathode discharge. The maximum char temperatures of Ag, Ga, Hg, Pb, Sb and Se were increased by 300–600°C in the presence of 1 μg of Pd, although the detection limits were a factor of two poorer.     

Use of sodium tungstate as a permanent chemical modifier for slurry sampling electrothermal atomic absorption spectrometric determination of indium in soils

A number of chemical modifiers have been assessed for the direct determination of indium in soils using electrothermal atomic absorption spectrometry and slurry sampling. The best results were obtained when the graphite atomizer was impregnated with sodium tungstate, which acts as a permanent chemical modifier. Slurries were prepared by suspending 100 mg sample in a solution containing 1% (v/v) concentrated nitric acid and 10% (v/v) concentrated hydrofluoric acid and then 15-microL aliquots were directly introduced into the atomizer. Standard indium solutions prepared in the suspension medium in the range 4-80 microg L(-1) indium were used for calibration. The relative standard deviation for ten consecutive measurements of a 40 microg L(-1) indium solution was 2.8%. The limit of detection in soils was 0.1 microg g(-1). The reliability of the procedures was confirmed by analysing two standard reference materials and by using an alternative procedure.     

Determination of lead in blood by tungsten coil electrothermal atomic absorption spectrometry

A method for the determination of lead in blood using a tungsten coil atomizer is described. A 100 μl volume of the whole blood sample is transferred to a sampler cup containing 100 μl of water plus 300 μl of 0.25% v/v Triton X-100. After lysis of blood cells, 500 μl of 10% w/v trichloroacetic acid is added for protein precipitation and 10 μl of the supernatant solution is automatically delivered into the tungsten coil. The furnace heating program is implemented in 41 s. It is shown by the paired t-test that there is no significant difference at the 5% probability level between results obtained by the proposed method and by using a transversely heated graphite atomizer with a longitudinal Zeeman background correction. Accuracy is also assessed by employing reference materials. The proposed tungsten coil procedure presents a characteristic mass of 15 pg Pb and a detection limit of 1.9 μg Pb dl⁻¹.     

Determination of Cd and Pb at μg/L levels by HHPN-beam injection flame furnace-AAS

Flame-heated tubes are widespread in flame-AAS, mainly for the determination of hydride-forming elements. Instead of the introduction of gaseous compounds liquids can also be introduced continuously in such an absorption cell. With the aid of an HPLC pump the liquid is forced through a very fine nozzle, generating an aerosol beam less than 0.5?mm in diameter. This beam travels a distance of 10?cm as a “free-flying aerosol jet” into the sample introduction hole of a metal tube furnace placed in the flame. Both introduction of the entire sample and the long residence time lead to a considerable improvement in power of detection. The detection limit for 100 μL samples amounts to 7 μg/L (Pb) and to 0. 2 μg/L (Cd), which means an increase in power of detection of between one and two orders of magnitude compared to conventional flame-AAS. The relative standard deviation (100 μL sample volume, N = 10) was found to be 1.3% (signal area) for 600 μg/L Pb and to be 1.5% (signal-area) for 15 μg/L Cd. RSD values from measurements in peak-height amounted to 2.2% (Pb) and to 1.7% (Cd).     

Slurry sampling graphite furnace atomic absorption spectrometry: determination of trace metals in mineral coal

A procedure for lead, cadmium and copper determination in coal samples based on slurry sampling using an atomic absorption spectrometer equipped with a transversely heated graphite tube atomizer is proposed. The slurries were prepared by weighing the samples directly into autosampler cups (5-30 mg) and adding a 1.5 ml aliquot of a diluent mixture of 5% v/v HNO(3), 0.05% Triton X-100 and 10% ethanol. The slurry was homogenized by manual stirring before measurement. Slurry homogenization using ultrasonic agitation was also investigated for comparison. The effect of particle size and the use of different diluent compositions on the slurry preparation were investigated. The temperature programmes were optimized on the basis of pyrolysis and atomization curves. Absorbance characteristics with and without the addition of a palladium-magnesium modifier were compared. The use of 0.05% m/v Pd and 0.03% m/v Mg was found satisfactory for stabilizing Cd and Pb. The calibration was performed with aqueous standards. In addition, a conventional acid digestion procedure was applied to verify the efficiency of the slurry sampling. Better recoveries of the analytes were obtained when the particle size was reduced to <37 mum. Several certified coal reference materials (BCR Nos. 40, 180, and 181) were analyzed, and good agreement was obtained between the results from the proposed slurry sampling method and the certificate values.     

Comparison of two digestion procedures for the determination of lead in lichens by electrothermal atomic absorption spectrometry

The efficiency of two procedures for the digestion of lichen was investigated using a heating block and a microwave oven. In the open vessels, concentrated nitric acid was added to the samples, left for 1 h, and the addition of 30% (v / v) hydrogen peroxide completed the digestion. In the closed system, the complete digestion was performed using concentrated nitric acid and hydrogen peroxide, reducing the amount of chemicals, time and contamination risk. Both digestion methods gave comparable results, and recoveries were statistically not different. For a lichen sample spiked with 10 μg Pb, the recovery was 111% and 110% using microwave and heating block digestion, respectively, while it was 100% and 103% for a 100 μg Pb spike. For the determination by electrothermal atomic absorption spectrometry samples were diluted 20 times with water and a volume of 20 μL was injected into the graphite furnace without chemical modifier. Pyrolysis and atomization temperatures of 700 °C and 1500 °C, respectively, were used. The characteristic mass was 8.4 ± 0.6 pg for aqueous calibration solutions and 8.9 ± 0.8 pg for samples. Calibration was against matrix matched standards. The recovery test showed some contamination problem with the lowest concentrations in both procedures. The detection limits were 4.4 μg L^− 1 with microwave oven and 5.4 μg L^− 1 with the heating block in the undiluted blank.     

Determination of Cd and Pb in food slurries by GFAAS using cryogenic grinding for sample preparation

A simple method combining slurry sampling after cryogenic grinding and the use of a permanent modification of the integrated platform inside the transversely heated graphite atomizer (THGA) was proposed for the determination of Cd and Pb in foods. Potentialities of the cryogenic grinding were evaluated for grinding different materials of difficult homogenization such as high fat and high fiber tissues. Animal and vegetal samples were cut into small pieces and ground in liquid nitrogen for 2 min. Slurries were prepared directly in the autosampler cup after cryogenic grinding by transferring an exact amount of homogeneous powdered material (5-20 mg) to the cup, followed by 1.00 mL of 0.2% (v/v) HNO3 containing 0.04% (v/v) Triton X-100 and sonication for 30 s, before transferring into the platform previously coated with 250 microg W and 200 microg Rh. Use of a tungsten carbide-rhodium permanent modifier combined with NH4H2PO4 conventional modifier improves tube lifetime and increases the pyrolysis temperature for Cd. Homogeneity tests, carried out by comparing the between- and within-batch precision for each kind of sample, showed no significant differences at the 95% confidence level, indicating good homogeneity for 5-20 mg masses. Detection limits were 3.3 ng g(-1) Cd and 75 ng g(-1) Pb for 1% m/v slurries. Results for determination of Cd and Pb in foods slurries were in agreement with those obtained with digested samples, since no statistical differences were found by the paired t-test at the 95% level.     

Total Sulfur Concentration in Tissues of Control and Cadmium-Exposed Rats by Inductively Coupled Plasma Atomic Emission Spectrometry

Abstract

Total sulfur (S) concentration in biological samples was determined simultaneously with metal concentrations by inductively coupled plasma-atomic emission spectrometry (ICP).

A 0.2 g portion of liver and other tissues were wet-digested with 1.0 ml mixed acid (HNO₃ : HCLO₄ = 5 : 1, v/v) at 130 – 150 °C. The solution was concentrated to about 0.1 ml and then diluted to 5.0 ml with double distilled water. Concentration of S was determined by ICP using ammonium sulfate as a standard S compound. Sulfur and other element concentrations in an NBS standard reference material (Bovine Liver SRM 1577) were within the certified values by this method.

Concentrations of total S, cadmium (Cd), copper (Cu) and zinc (Zn) in the liver, kidney, spleen, lung, pancreas and blood serum were compared between the control and Cd-exposed rats. The three metal concentrations were increased significantly by Cd exposure. However, S concentration was not altered significantly in the liver and other tissues despite the extensive induction of metallothionein (MT) by the repeated Cd exposure. Metallothionein induced by the accumulated Cd (121 μg/g) and Zn (48 μg/g) in the liver was estimated to account for at maximum 7 % of the total S by assuming that the increased metals were all bound to MT. Concentration of S in blood serum was decreased significantly by Cd loading.     

On-line coupling of electrochemical preconcentration in tungsten coil electrothermal atomic absorption spectrometry for determination of lead in natural waters

A flow injection system was coupled to a tungsten coil electrothermal atomizer (150 W) for on-line separation and preconcentration of lead based on its electrochemical reduction on the atomizer surface. The electrochemical cell is built up inside the furnace by using a Pt flow-through anode and the atomizer itself as the flow-through cathode. The manifold and the tungsten coil power supply were controlled by a computer running a program written in Visual Basic, which was utilized in synchronism with the original software of the atomic absorption spectrometer. The flow-through anode (50 mm long, 0.7 mm i.d.) was inserted in tip of the autosampler arm by replacing the last section of the PTFE sample delivering tube. The tungsten coil atomizer and the counter electrode were easily connected to a d.c. power supply. An enrichment factor of 25 was obtained for lead after a 120-s electrodeposition for a sample flowing at 1.0 ml min⁻¹. The method detection limit was 0.2 μg l⁻¹ Pb and the R.S.D.<5% (n=10 for 5 μg l⁻¹ Pb). Up to 2% m/v NaCl or KCl and 5% m/v CaCl₂ or MgCl₂ did not interfere on the separation and atomization of 5 μg l⁻¹ Pb.     

Combining Ammonium Pyrrolidine Dithiocarbamate/methyl Isobutyl Ketone Microextraction in an Inexpensive Disposable Pipette with Laser Ablation Inductively Coupled Plasma Mass Spectrometry for the Determination of Cd and Pd

This paper describes a new analytical method, using a combination of ammonium pyrrolidine dithiocarbamate/methyl isobutyl ketone (APDC‐MIBK) microextraction and laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS), for the determination of the concentrations of Cd and Pb in aqueous samples. Only 200 μL of organic solvent was used throughout the entire analysis process, with enhancement factors as high as 25. Recoveries from replicate analyses of natural water [NIST 1640(a)] containing mean concentrations of 3.1 μg Cd L^?1 and 9.3 μg Pb L^?1 were 95 ± 3 and 104 ± 4%, respectively. The corresponding detection limits were 0.6 μg L ^?1 for Cd and 0.9 μg L ^?1 for Pb. The main advantage of this approach is its simplicity in terms of sample preparation, as demonstrated by quantifying the levels of Cd and Pd in real samples, including tap water, groundwater, and seawater, using a standard addition method.     

Development of a sensitive liquid chromatography/tandem mass spectrometry method for the determination of fenofibric acid in rat plasma

A rapid and sensitive LC‐MS/MS method for the quantification of fenofibric acid in rat plasma was developed and validated. Plasma samples were prepared by liquid–liquid extraction with a mixture of N‐hexane–dichloromethane–isopropanol (100:50:5, v/v/v). Isocratic chromatographic separation was performed on a reversed‐phase Discovery C₁₈ column (2.1 × 50 mm, 5 µm). The mobile phase was methanol–water–formic (75:25:0.25, v/v/v). Detection of fenofibric acid and the internal standard (IS) diclofenac acid was achieved by ESI MS/MS in the negative ion mode using m/z 317 → m/z 213 and m/z 294 → m/z 250 transitions, respectively. The method was linear from 0.005 to 1.250 µg/mL when 100 μL plasma was analyzed. The lower limit of quantification was 0.005 µg/mL. The intra‐ and inter‐day precision values were below 8.2%, and accuracy ranged from ?0.9 to 2.1% in all quality control samples. The recovery was 90.3–94.7% and 83.3% for fenofibric acid and IS, respectively. Total run time for each sample analysis was 2.5 min. The validated method was successfully applied to a pharmacokinetic study in six rats after oral administration of fenofibrate, the ester prodrug of fenofibric acid (equivalent to fenofibric acid 5 mg/kg). The method permits laboratory scientists with access to the appropriate instrumentation to perform rapid fenofibric acid determination. Copyright © 2011 John Wiley & Sons, Ltd.     

Analysis of nucleotides directly from TLC plates using MALDI-MS detection

The natural pyrethrins, cinerin I, jasmolin I and pyrethrin I, have been hydrolyzed to chrysanthemic acid (CA) in subcritical water in the presence of basic alumina. The hydrolysis and extraction was performed in situ with subcritical water. The conversion to acid is reproducible at 200?°C and 30 min with an RSD of 19% (n = 16) at a concentration level of 1.2 × 10^–8 mol/L CA and 12% (n = 12) at concentration level of 1.2 × 10^–7 mol/L CA. An analytical method using Solid Phase Micro Extraction (SPME) combined with GC-FID or -MSD was developed and optimized. For SPME an equilibration time of 20 min at pH of 2 was required. Three fibers, 100 μm polydimethylsiloxane (PDMS), 85 μm polyacrylate (PA) and 65 μm carbowax/divinylbenzene (CW) were evaluated. The Carbowax/divinylbenzene fiber has the highest affinity for CA, but the capacity decreases significantly from experiment to experiment. The most reproducible and most stable one was the PDMS fiber. Two internal standards, octanoic acid and cis-chrysanthemic acid, were used because CA degrades slowly at 200?°C in water. This method was applied to analyze some products which contain pyrethrum as an active ingredient, such as insect spray, shampoo against lice, and dried chrysanthemum flowers. The results are comparable to SFC-FID data and correspond to the values given by the manufacturer.     

The Enrichment/Separation of Fe, Co, Pb, Cd, and Cr on Ambersorb 563 Prior to Their Flame Atomic Absorption Spectrometric Determinations

A sorbent extraction method for the separation/preconcentration of Fe, Co, Pb, Cd, and Cr was developed. The analyte metal ions were retained on a column of Ambersorb 563 from a buffered sample solution. The flow rates of the sample and eluent solution were controlled by a peristaltic pump. The analyte ions were quantitatively retained at pH 9 by using an ammonia/ammonium chloride buffer solution, and were then eluted with 5 mL of 0.25 M HNO₃ at 5 mL/min flow rate. The detection limits were in the range of 0.33 and 72 g/L for Cd and Pb, respectively. The relative standard deviations were less than 10%. Recoveries of spike addition to drinking water and seawater were quantitative. The method presented was applied for the determination of Fe, Co, Pb, Cd, and Cr ions in drinking and seawater samples with satisfactory results (recoveries >95%).     

Membrane Filtration of Iron(III), Copper(II) and Lead(II) Ions as 1‐(2‐Pyridylazo) 2‐Naphtol (PAN) for Their Preconcentration and Atomic Absorption Determinations

A membrane filtration procedure for the preconcentration and atomic absorption spectrometric determination of Pb(II), Co(II) and Fe(III) ions in natural water samples has been established. Cellulose nitrate membrane filters (0.45 μm and 47 mm diameter) were used in all experiments. The procedure is based on chelate formation of the analyte metals with 1‐(2‐pyridylazo) 2‐naphtol (PAN) and on retention of the chelates on cellulose nitrate membrane filter. The cellulose nitrate membrane and analyte ions were completely dissolved by 500 μL of nitric acid at 85 °C on a hood and then metal determinations were performed by flame atomic absorption spectrometry. The method was applied to natural water samples for the determination of analyte ions with satisfactory results, e.g., recoveries > 95%, RSD's < 10%.     

Simultaneous Determination of Aluminum,Cadmium and Lead in Whole Blood by Simultaneous Atomic Absorption Spectrometry with Oxygen Charring

A method for the simultaneous determination of aluminum (Al), cadmium (Cd) and lead (Pb) in whole blood has been developed by using simultaneous atomic absorption spectrometry (SIMAAS) with oxygen charring. The optimized conditions for the simultaneous determination of Al, Cd and Pb were obtained in the presence of palladium (Pd) as the chemical modifier, using 600 °C and 2400 °C as the pyrolysis and the atomization temperature, respectively. The whole blood samples were diluted 1+5 (v/v) directly with 0.1% (v/v) Triton X‐100. Oxygen was employed to eliminate the interference of carbonaceous residues in the charring step before pyrolysis. The calibration curves were carried out with aqueous standard solutions and the linear ranges were 0–40 ng mL⁻¹, 0–4 ng mL⁻¹ and 0–40 ng mL⁻¹ for Al, Cd and Pb, respectively. The detection limits were 0.96 ng mL⁻¹ (19.2 pg) for Al, 0.03 ng mL⁻¹ (0.6 pg) for Cd and 0.60 ng mL⁻¹ (12.0 pg) for Pb. The spiked recoveries of Al, Cd and Pb in whole blood were 98.0%, 100.0% and 101.7%, respectively. The accuracy of the proposed method was evaluated with the analysis of a whole blood certified reference material (Seronorm, level 2). The found concentrations were in agreement with the recommended values. The proposed method has been successfully applied to the simultaneous determination of Al, Cd and Pb in whole blood of healthy volunteers before and after eating barbecued foods.