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Conditions for the determination of Ni and Cr in seawater by high-resolution continuum source electrothermal atomic absorption spectrometry (HR-CS ETAAS) are developed. Nitric acid is used as a chemical modifier. The analytical capabilities of this method are compared with those of the version of low-resolution line source electrothermal atomic absorption spectrometry (LR-LS ETAAS) with deuterium background correction. A calibration dependence is constructed on standard analyte solutions. Procedures for determining Cr and Ni are tested on water samples from the Black Sea using the spiked test. Using the HR-CS ETAAS method, limits of detection (μg/L) of 0.12 for Cr and 0.09 for Ni (dosage 80 μL) are achieved. For the LR-LS ETAAS method, these indicators are worse: 0.6 (Cr) and 1 μg/L (Ni) with a dosed volume of seawater sample of 10 μL. A possibility of using the ETAAS method for the direct determination of Cr and Ni contents in seawater at a level two orders of magnitude lower than their maximum permissible concentrations is demonstrated.integral absorbance [ABSTRACT FROM AUTHOR]

A procedure is proposed for the direct determination of lead in sea water by electrothermal atomization high-resolution atomic absorption spectrometry. The effect of background interferences due to sea water matrix is eliminated using a mixed modifier barium nitrate–hydrofluoric acid. The optimum amount of the modifier matrix is 60 µg Ba (NO3)2 + 1.52 µg HF. The conditions of analysis are as follows: pyrolysis temperature 600°C, atomization temperature 1200°C. The limit of detection for the developed procedure is 0.0003 mg/L. [ABSTRACT FROM AUTHOR]

Abstract: A procedure is developed for the simultaneous highly sensitive determination of eight chlorophenols in sea water based on a combination of isotope dilution, solid-phase extraction on an octadecyl adsorbent, acetylation, and determination by gas chromatography-tandem mass spectrometry with electron ionization. The attained limits of detection for the analytes are in the range 0.06−0.26 ng/L, which is 2−3 orders of magnitude lower than the standards established for the maximum permissible concentration. The duration of analysis is 15 min. The application of a deuterated internal standard ensures the high accuracy and reproducibility of the results obtained. The developed procedure was successfully used for the analysis of real water samples from the Barents Sea; the found total chlorophenol concentration in them was 15-24 ng/L. The main pollutant of the studied sea water samples is 2,4-dichlorophenol, which comprised about 30% of the total concentration of chlorophenols. [ABSTRACT FROM AUTHOR]