Determination of lead in waters and sediments from the wetland Tablas de Daimiel National Park (Spain)

Electrothermal atomic absorption spectrometry (ETAAS) has been used for lead control in waters and sediments of the wetland Tablas de Daimiel National Park. The lead determination in the wetland water is hindered by an enhanced salt content, so matrix interference was evaluated. The use of stabilized temperature platform atomization technique, Zeeman background correction and palladium nitrate as matrix modifier were found advisable. For the sediments a closed-vessel microwave dissolution method has been proposed using a mixture of HCl-HNO₃-HF and a heating time of 90 s. With subsequent ETAAS using platform atomization and Zeeman background correction, no chemical modification was necessary. Using these conditions, the interferences were completely removed for both waters and sediments and the calibration curve in ultrapure water (1% nitric acid) was linear up to 30 μg/L. The detection limits for waters and sediments were 0.95 μg/L and 0.78 μg/g, respectively. The accuracy of the proposed method for sediments was validated by analyzing certified reference materials (obtained values were within the certified ones) and spiked wetland sediments (mean recovery of 99.0%). Received: 11 October 1998 / Revised: 3 December 1998 / Accepted: 11 March 1999     

Chromium determination in sea water by electrothermal atomic absorption spectrometry using Zeeman effect background correction and a multi-injection technique

Electrothermal atomic absorption spectrometry (ETAAS) applying a Zeeman effect background correction system (ZEBC) and a tranverse heated atomizer was used to directly determine chromium in sea water. Calcium chloride (at a concentration of 20 mg L^–1) was applied as chemical modifier with optimum charring and atomization temperatures of 1600°C and 2000°C, respectively. The detection limit was 0.2 μg L^–1, by injecting 20 μL aliquot of sea water sample. This detection limit could be reduced further to 0.05 μg L^–1, using multiple injections (injection of five 20 μL aliquot of sea water). The accuracy of the methods developed were confirmed by analyses of different certified reference materials. Finally, interferences from major and minor components of sea water are studied. Received: 20 February 1997 / Revised: 26 May 1997 / Accepted: 8 June 1997     

Determination of Antimony in Sediments by Zeeman-Corrected Electrothermal Atomic Absorption Spectrometry with Ultrasonic Slurry Sampling

A method was developed for the determination of antimony in slurried sediments (on the basis of samples of three Certified Reference Materials) by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman-effect background correction. Slurried samples were prepared in 6% nitric acid containing 0.02% of Triton X-100. A mixed palladium/magnesium chemical matrix modifier, L'vov platform atomization and a temperature-time program with a relatively short (10 s) sample pyrolysis stage were used. The results of the determinations by this technique are in very close agreement with certified values and the repeatability of this analytical procedure expressed in terms of relative standard deviation was typically better than 9% at the slurry concentration of approx. 90 mg/2 mL. The characteristic mass of Sb (at the spectral line 231.1 nm) was 25.6 pg and the limit of detection (calculated for 100 mg/2 mL slurry) was about 0. 04 μg/g.     

Appraisal of different electrothermal atomic absorption spectrometric methods for the determination of strontium in biological samples

A comparative study of various potential chemical modifiers (La, Mg, Pd, Ni, Ta, Lu, Sm, Eu, Ho, Er, Tm and Tb) as well as of different background correction procedures (deuterium and Zeeman effect) and atomization techniques (wall and platform) for the direct determination of strontium in biological samples was carried out. Two instruments, one with deuterium and the other with Zeeman effect background corrections have been used to perform the experiments. Although La, Mg, Pd, Ta and Lu had a positive effect, lanthanum alone provided the best performance for the determination of strontium in whole blood, urine and bone digests using wall atomization without deuterium background correction. However, neither chemical modifier produced any significant improvement in sensitivity when Zeeman effect background correction with integrated platform atomization was used. Under the optimized conditions, the characteristic masses were 0.82 and 2.20 pg and the detection limits (3σ) were 0.13 and 0.30 μg l⁻¹ with wall atomization and with Zeeman effect background correction respectively. Recovery studies and analysis of standard reference materials certified for strontium were performed to assess the accuracy. The results for the determination of strontium in real samples with wall atomization and lanthanum as chemical modifier, agreed well with those obtained with Zeeman effect background corrector with a precision typically between 0.5 and 3%. Both procedures can be recommended, and the choice will depend on instrument availability.     

Determination of zinc in gallium arsenide by electrothermal atomic absorption spectrometry with the L''vov platform and matrix modification

Summary A method is described for the determination of zinc in gallium arsenide by ETAAS with platform atomization and matrix modification. The sample is decomposed with nitric and hydrochloric acids, ortho-phosphoric acid is added as a matrix modifier and the diluted solution is injected into the furnace. The optical correction of the nonspecific absorbance is readily achieved by means of a conventional deuterium lamp. Platform atomization improves the peak repeatability by a factor often in comparison with wall atomization. For a 40 mg sample, with reduced argon flow rate in the atomization step, the detection limit is 0.08 g Zn g^–1 (4×10¹⁵ atoms cm^–3). Results obtained by analysing Zn-doped GaAs samples are presented. The relative standard deviation of the overall procedure is 4–8%.

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Bestimmung von Zink in Galliumarsenid durch ETAAS mit L'vov-Plattform und Matrixmodifizierung

     

Determination of cadmium in indium phosphide by electrothermal atomic absorption spectrometry and ion-selective electrode potentiometry

 Two independent methods for the determination of cadmium in cadmium-doped indium phosphide have been developed. Electrothermal atomic absorption spectrometry (ETAAS) utilized both platform atomization and a chemical modifier composed of magnesium nitrate and orthophosphoric acid. As the matrix mass was found to influence the cadmium sensitivity, matrix matched calibration standards were necessary. The detection limit (3s_B) is 0.20 μg/g for a 100 mg sample. The electrochemical method employed a solid-state cadmium sulfide-silver sulfide electrode as potentiometric sensor. An excess of indium (III) influenced the electrode response. A preliminary chelation-extraction of indium with acetylacetone at pH 5.0 in acetate buffer overcame the interference. The detection limit of the ISE-potentiometric method is 10 μg/g for a 200 mg sample. Two indium phosphide single crystals grown from melts doped with cadmium sulfide or cadmium telluride were analyzed for their cadmium content. Received: 27 August 1996/Revised: 27 January 1997/Accepted: 30 January 1997     

ETAAS method for the determination of Cd, Cr, Cu, Mn and Se in blood fractions and whole blood

An electrothermal atomic absorption method (ETAAS) for the direct determination of trace elements (Cd, Cr, Cu, Mn, Se) both in blood fractions (erythrocytes, plasma and lymphocytes) and whole blood was developed. Zeeman background correction and graphite tubes with L’vov platforms were used. Samples were ¶diluted with HNO₃/Triton X-100 and pipetted directly ¶into the graphite tube. Ashing, pretreatment and atomization steps were optimized carefully for the different fractions and elements applying different matrix modifiers ¶for each element. For the lymphocyte fraction a multi-fold injection technique was applied. Low detection limits ¶of the ETAAS method (Cd 0.13 μg/L, Cr 0.11 μg/L, ¶Cu 0.52 μg/L, Mn 0.13 μg/L, Se 0.7 μg/L of whole blood) combined with small quantities of sample necessary for analysis allow determination of trace elements in this matrix. Verification of possible differences in the trace element status of humans was performed with statistical significance (P < 0.05). In addition, a contribution to the determination of normal values of essential elements was achieved. The method was applied for determination of trace elements in human blood and blood fractions of two groups (n = 50) different in health status.     

Chromium determination in sea water by electrothermal atomic absorption spectrometry using Zeeman effect background correction and a multi-injection technique

Electrothermal atomic absorption spectrometry (ETAAS) applying a Zeeman effect background correction system (ZEBC) and a tranverse heated atomizer was used to directly determine chromium in sea water. Calcium chloride (at a concentration of 20 mg L^–1) was applied as chemical modifier with optimum charring and atomization temperatures of 1600°C and 2000°C, respectively. The detection limit was 0.2 μg L^–1, by injecting 20 μL aliquot of sea water sample. This detection limit could be reduced further to 0.05 μg L^–1, using multiple injections (injection of five 20 μL aliquot of sea water). The accuracy of the methods developed were confirmed by analyses of different certified reference materials. Finally, interferences from major and minor components of sea water are studied.     

An assessment of contemporary atomic spectroscopic techniques for the determination of lead in blood and urine matrices

The preparation and validation of a number of clinical reference materials for the determination of lead in blood and urine is described. Four candidate blood lead reference materials (Lots, 047–050), and four candidate urine lead reference materials (Lots, 034, 035, 037 and 038), containing physiologically-bound lead at clinically relevant concentrations, were circulated to up to 21 selected laboratories specializing in this analysis. Results from two interlaboratory studies were used to establish certified values and uncertainty estimates for these reference materials. These data also provided an assessment of current laboratory techniques for the measurement of lead in blood and urine. For the blood lead measurements, four laboratories used electrothermal atomization AAS, three used anodic stripping voltammetry and one used both ETAAS and ICP-MS. For the urine lead measurements, 11 laboratories used ETAAS (most with Zeeman background correction) and 10 used ICP-MS. Certified blood lead concentrations, ±S.D., ranged from 5.9±0.4 μg/dl (0.28±0.02 μmol/l) to 76.0±2.2 μg/dl (3.67±0.11 μmol/l) and urine lead concentrations ranged from 98±5 μg/l (0.47±0.02 μmol/l) to 641±36 μg/l (3.09±0.17 μmol/l). The highest concentration blood lead material was subjected to multiple analyses using ETAAS over an extended time period. The data indicate that more stringent internal quality control practices are necessary to improve long-term precision. While the certification of blood lead materials was accomplished in a manner consistent with established practices, the urine lead materials proved more troublesome, particularly at concentrations above 600 μg/l (2.90 μmol/l).     

Determination of serum aluminum by electrothermal atomic absorption spectrometry: A comparison between Zeeman and continuum background correction systems

Excessive exposure to aluminum (Al) can produce serious health consequences in people with impaired renal function, especially those undergoing hemodialysis. Al can accumulate in the brain and in bone, causing dialysis-related encephalopathy and renal osteodystrophy. Thus, dialysis patients are routinely monitored for Al overload, through measurement of their serum Al. Electrothermal atomic absorption spectrometry (ETAAS) is widely used for serum Al determination. Here, we assess the analytical performances of three ETAAS instruments, equipped with different background correction systems and heating arrangements, for the determination of serum Al. Specifically, we compare (1) a Perkin Elmer (PE) Model 3110 AAS, equipped with a longitudinally (end) heated graphite atomizer (HGA) and continuum-source (deuterium) background correction, with (2) a PE Model 4100ZL AAS equipped with a transversely heated graphite atomizer (THGA) and longitudinal Zeeman background correction, and (3) a PE Model Z5100 AAS equipped with a HGA and transverse Zeeman background correction. We were able to transfer the method for serum Al previously established for the Z5100 and 4100ZL instruments to the 3110, with only minor modifications. As with the Zeeman instruments, matrix-matched calibration was not required for the 3110 and, thus, aqueous calibration standards were used. However, the 309.3-nm line was chosen for analysis on the 3110 due to failure of the continuum background correction system at the 396.2-nm line. A small, seemingly insignificant overcorrection error was observed in the background channel on the 3110 instrument at the 309.3-nm line. On the 4100ZL, signal oscillation was observed in the atomization profile. The sensitivity, or characteristic mass (m₀), for Al at the 309.3-nm line on the 3110 AAS was found to be 12.1 ± 0.6 pg, compared to 16.1 ± 0.7 pg for the Z5100, and 23.3 ± 1.3 pg for the 4100ZL at the 396.2-nm line. However, the instrumental detection limits (3 SD) for Al were very similar: 3.0, 3.2, and 4.1 μg L^− 1 for the Z5100, 4100ZL, and 3110, respectively. Serum Al method detection limits (3 SD) were 9.8, 6.9, and 7.3 μg L^− 1, respectively. Accuracy was assessed using archived serum (and plasma) reference materials from various external quality assessment schemes (EQAS). Values found with all three instruments were within the acceptable EQAS ranges. The data indicate that relatively modest ETAAS instrumentation equipped with continuum background correction is adequate for routine serum Al monitoring.     

Determination of lead concentration and lead isotope ratios in calcium supplements by inductively coupled plasma mass spectrometry after high pressure, high temperature digestion

The presence of lead as a contaminant in calcium supplements has aroused considerable public health interest in recent years. In this investigation lead and lead isotope ratios were determined by ICP-MS in ten brands of calcium supplements after high pressure/temperature digestion. Calcium supplements (200 to 250 mg) were digested in 2 mL of nitric acid at 230 °C and at a pressure of 1770 psi (1.2 × 10⁴ kPa). Lead concentrations were determined by matrix-matched lead standards prepared in a high-purity calcium carbonate matrix. Good recoveries of lead and calcium were obtained for certified animal bone reference material. High levels of Pb (8 to 28 μg Pb per g of calcium) were found in calcium supplements that contain dolomite or bone meal. Chelated and refined calcium supplements had lower Pb levels (0.8 to 0.9 μg Pb/g Ca). Application of lead isotope ratios to distinguish the origin of calcium sources was also explored. Received: 9 June 1998 / Revised: 20 July 1998 / Accepted: 25 July 1998     

On the determination of lead in wine by electrothermal atomic absorption spectrometry

The parameters of analytical procedures developed for direct ETAAS determination of Pb in wine are discussed. Atomic absorption spectrometers based on transversal and longitudinal Zeeman effect, wall and integrated platform atomization with two main approaches: (i) measurements in the presence of modifier and (ii) measurements without using any modifier are compared. The optimal temperature programs are defined according to the pre-treatment and atomization curves constructed in the presence of different types of wines. For all investigated instrumental systems, 1:1 dilution of wine sample with 0.2 mol L⁻¹ HNO₃ is recommended. Matrix interferences observed, call for standard addition calibration method for Pb quantification in wines. The detection limit (3σ) achieved for wine diluted in the ratio of 1:1 varied from 0.8 to 1.9 μg L⁻¹ depending on the instrument used. The relative standard deviation for the concentration range of 10 to 80 μg L⁻¹ Pb in wine is typically between 4–8%. The accuracy of the analytical procedures recommended was confirmed by comparing the results obtained with those found for wine samples previously digested with HNO₃-H₂O₂ mixture, by added/found method and by parallel analysis using different instruments. A total of 66 wine samples from different regions of Macedonia were analyzed.      

Determination of As in environmental solid matrix

In line with recent European environmental guidelines on biomasses, one of the most important parameters to take into account is the As concentration, especially when present in biomasses and complex matrices. The goal of the present study is to give information about possible technical-analytical problems during the determinations of such elements by means of different instrumental spectroscopy techniques, in particular inductively coupled plasma atomic emission (ICP-AES) and atomic absorption (AAS), using two different wavelengths, 188.98 nm and 193.70 nm.In the Laboratory of Hygiene of National Institute of Health in Italy, a specific study has been carried out concerning the determination of As contents in environmental solid matrices, using as reference material BCR 141 R, represented by a calcareous soil. In particular, whereas recovery tests did not show particular drawbacks, difficulties were met in the As detection in reference material. Spectral interference was seen during determination by ICP-AES and matrix interference during determination by AAS, in particular using ETAAS with deuterium background correction and HAAS. Using ETAAS with Zeeman background correction at 193.70 nm, the As line did not show particular matrix interference during the reading of samples.A ring test involving two more laboratories and another certified reference material (IAEA-356 in marine sediment matrix) produced important information about problems of under/over estimation of data. Two different instrumental techniques, ICP-MS and HAAS, confirmed previous data, i.e., overestimation for inductively coupled plasma mass spectrometry and that As values achieved by HAAS were of the same order as the references, but affected by considerable standard deviation.In the light of this study, data achieved on the environmental matrices investigated suggest that the critical step in As determination is the instrumental reading, rather than the mineralization process. Further, each of the methods proposed, apart from ETAAS with Zeeman background correction, presents its own peculiar drawbacks and no particular advantage over other techniques.     

Determination of the enantiomeric purity of amphetamine after derivatization with Sanger’s reagent (2,4-dinitrofluorobenzene [DNFB]) by simultaneous dual circular dichroism and ultraviolet spectroscopy

Determination of Se in biological materials was attempted by microwave-induced plasma mass spectrometry (MIP-MS). (1) Serum samples were available after 10 times dilution with 0.5% nitric acid solution containing 0.1% Triton X-100. When oxygen gas was inserted into the plasma gas (nitrogen) in order to improve the combustion, the sensitivity was reduced to 45%. The detection limit of this method was 0.5 ng/mL. (2) Standard reference materials on commercial base were used to evaluate the accuracy of the Se determination by MIP-MS after microwave digestion. In samples like bovine liver and human hair with Se concentrations of more than 0.7 μg/g, the standard curve method after internal standard (IS) correction was acceptable. This procedure was unsuitable for samples with low Se concentrations such as milk powder (certified value of Se 0.11 μg/g), or plant leaf samples. (3) Instead of IS correction, the peak height of the spectrum was used for calculations from the matrix matched calibration curve. The results of all materials were close to the certified values, even at 25 ng/g. The detection limit of the MIP-MS with microwave digestion and IS correction was 0.05 ng/mL in standard solutions. The detection limit of the peak height method was 0.1 ng/mL and was estimated to be < 20 ng/g in plant materials. Received: 25 September 1998 / Revised: 15 February 1999 / Accepted: 18 February 1999     

Determination of cadmium, copper and lead in soils, sediments and sea water samples by ETAAS using a Sc + Pd + NH(4)NO(3) chemical modifier

Cadmium, copper and lead in soils, sediments and spiked sea water samples have been determined by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman effect background corrector using NH₄NO₃, Sc, Pd, Sc + NH₄NO₃, Pd + NH₄NO₃, Sc + Pd and Sc + Pd + NH₄NO₃ as chemical modifiers. A comprehensive comparison was made among the modifiers and without modifier in terms of pyrolysis and atomization temperatures, atomization and background absorption profiles, characteristic masses, detection limits and accuracy of the determinations. Sc + Pd + NH₄NO₃ modifier mixture was found to be preferable for the determination of analytes in soil and sediment certified and standard reference materials, and sea water samples because it increased the pyrolysis temperature up to 900 °C for Cd, 1350 °C for Cu and 1300 °C for Pb. Optimum masses of mixed modifier components found are 20 μg Sc + 4 μg Pd + 8 μg NH₄NO₃. Characteristic masses of Cd, Cu and Pb obtained are 0.6, 5.3 and 15.8 pg, respectively. The detection limits of Cd, Cu and Pb were found to be 0.08, 0.57 and 0.83 μg l⁻¹, respectively. Depending on the solid sample type, the percent recoveries were increased up to 103% for Cd, Cu and Pb by using the proposed modifier mixture. The accuracy of the determination of analytes in the sea water samples was also increased.     

Determination of iron in seawater by electrothermal atomic absorption spectrometry and atomic fluorescence spectrometry: A comparative study

Two methods available for direct determination of total Fe in seawater at low concentration level have been examined: electrothermal atomization atomic absorption spectrometry (ETAAS) and electrothermal atomization laser excited atomic fluorescence spectrometry (ETA-LEAFS). In a first part, we have optimized experimental conditions of ETAAS (electrothermal program, matrix chemical modification) for the determination of Fe in seawater by minimizing the chemical interference effects and the magnitude of the simultaneous background absorption signal. By using the best experimental conditions, a detection limit of 80 ng L⁻¹ (20 μL, 3σ) for total Fe concentration was obtained by ETAAS. Using similar experimental conditions (electrothermal program, chemical modification), we have optimized experimental conditions for the determination of Fe by LEAFS. The selected experimental conditions for ETA-LEAFS: excitation wavelength (296.69 nm), noise attenuation and adequate background correction led to a detection limit (3σ) of 3 ng L⁻¹ (i.e. 54 pM) for total Fe concentration with the use a 20 μL seawater sample. For the two methods, concentration values obtained for the analysis of Fe in a NASS-5 (0.2 μg L⁻¹) seawater sample were in good agreement with the certified values.     

Evaluation of electrodeposited tungsten chemical modifier for direct determination of chromium in urine by ETAAS

The direct determination of chromium in urine by electrothermal atomic absorption spectrometry (ETAAS) using graphite tubes modified with tungsten is proposed. Modification of the graphite is made by tungsten electrodeposition over the whole surface atomizer followed by carbide formation by heating the tube inside its own furnace. For tungsten electrocoating, the graphite tube and a platinum electrode were connected to a power supply as cathode and anode, respectively, and immersed in a solution containing 2 mg of W in 0.1% v/v HNO₃. Then, 5 V was applied between the electrodes during 20 min for tungsten electrodeposition over the whole atomizer. A SpectrAA 220 Varian atomic absorption spectrometer equipped with a deuterium background corrector was used throughout. Undiluted urine (20 μl) was delivered over the tungsten-treated tube and the chromium-integrated absorbance was measured after applying a suitable heating program with maximum pyrolysis at 1300 °C and atomization at 2500 °C. With electrodeposited tungsten modifier, the tube lifetime increased up to four times when compared to previous published methods for Cr determination in urine by ETAAS, reaching 800 firings. Method detection limit (3 S.D.) was 0.10 μg l⁻¹, based on 10 integrated absorbance measurements of a urine sample with low Cr concentration. Two reference materials of urines (SRM 2670) from National Institute of Standards and Technology (NIST) were analyzed for method validation. For additional validation, results obtained from eight human urine samples were also analyzed in a spectrometer with Zeeman effect background correction.     

Molybdenum, Mo-Ir and Mo-Ru coatings as permanent chemical modifiers for the determination of cadmium and lead in sediments and soil samples by electrothermal atomic absorption spectrometry

Molybdenum, Ir, Ru, Mo-Ir, Mo-Ru thermally coated on to platforms inserted in pyrolytic graphite tubes as permanent modifiers and Pd + Mg(NO₃)₂ conventional modifier mixture have been employed for the determination of cadmium and lead in dissolved sediments and soil samples by electrothermal atomic absorption spectrometry (ETAAS). Optimum masses and mass ratios of permanent modifiers for the analysis of Cd and Pb in sample solutions have been investigated. The 280 μg of Mo, 200 μg of Ir, 200 μg of Ru, 280 μg of Mo + 200 μg of Ir or 280 μg of Mo + 200 μg of Ru has been found as efficient as 5 μg of Pd + 3 μg of Mg(NO₃)₂ for increasing thermal stabilization of analytes and for decreasing the most serious interferences. Pyrolysis and atomization temperatures, atomization and background signal shapes, characteristic masses and detection limits of analytes in dissolved samples with or without permanent and conventional modifiers have been compared. The detection limits and characteristic masses obtained with Mo-Ir coated platform are 0.01 μg g⁻¹ and 1.1 pg for Cd and 0.09 μg g⁻¹ and 19 pg for Pb, respectively. Long-term stabilities for analytes in samples with Mo, Mo-Ir, Mo-Ru and Pd + Mg(NO₃)₂ have been studied. Cadmium and lead contents have been determined in certified and standard reference materials by using optimum conditions investigated and the results obtained with Mo-Ir or Mo-Ru were in agreement with the values of certified reference materials.     

ETAAS method for the determination of Cd, Cr, Cu, Mn and Se in blood fractions and whole blood

An electrothermal atomic absorption method (ETAAS) for the direct determination of trace elements (Cd, Cr, Cu, Mn, Se) both in blood fractions (erythrocytes, plasma and lymphocytes) and whole blood was developed. Zeeman background correction and graphite tubes with L'vov platforms were used. Samples were diluted with HNO3/Triton X-100 and pipetted directly into the graphite tube. Ashing, pretreatment and atomization steps were optimized carefully for the different fractions and elements applying different matrix modifiers for each element. For the lymphocyte fraction a multi-fold injection technique was applied. Low detection limits of the ETAAS method (Cd 0.13 microgram/L, Cr 0.11 microgram/L, Cu 0.52 microgram/L, Mn 0.13 microgram/L, Se 0.7 microgram/L of whole blood) combined with small quantities of sample necessary for analysis allow determination of trace elements in this matrix. Verification of possible differences in the trace element status of humans was performed with statistical significance (P < 0.05). In addition, a contribution to the determination of normal values of essential elements was achieved. The method was applied for determination of trace elements in human blood and blood fractions of two groups (n = 50) different in health status.     

Direct electrothermal atomic absorption spectrometry determination of nickel in sea water using multiple hot injection and Zeeman correction

Methods for the direct determination of Ni in sea water samples by ETAAS were developed using Zeeman effect background correction system (ZEBC) and a multi-injection technique. A mass of palladium nitrate of 2.5 mug (for an injection volume of 100 mul) was used as chemical modifier. The optimum pyrolysis and atomization temperatures were 1700 and 2100 degrees C, respectively. The characteristic mass (m(0)) and characteristic concentration (C(0)), precision and accuracy were studied for different injection volumes (20, 100 and 200 mul). For an injection volume of 100 mul (five 20 mul aliquot) of sample the accuracy analysis of different certified materials (saline and non saline water) was agreeable. The total time of the proposed procedure is 6 min. A m(0) and C(0) of 34.5 pg and 0.3 mug l(-1), respectively were obtained for this injection volume (100 mul). Finally, interferences from major and minor components of sea water was studied.