Sensitive determination of mercury in tap water by cloud point extraction preconcentration and flow injection-cold vapor-inductively coupled plasma optical emission spectrometry

JORGELINA C. A. DE WUILLOUD; RODOLFO WUILLOUD; M. FERNANDA SILVA; ROBERTO A. OLSINA; L. DANTE MARTÍNEZ

SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY

Elsevier

Año: 2002 vol. 57 p. 365 - 374

0584-8547

A pre-concentration and determination methodology for mercury at trace levels in water samples was developed. Cloud point extraction was successfully employed for the pre-concentration of mercury prior to inductively coupled plasma optical emission spectrometry coupled to a flow injection with cold vapor generation system. The mercury was extracted as mercury-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol wHg(II)-(5-Br-PADAP)x complex, at pH 9.2 mediated by micelles of the non-ionic surfactant polyethyleneglycolmono-p-nonylphenylether (PONPE 5). Cold vapor generation was developed from 100 ml of the extracted surfactant-rich phase by means of a stannous chloride(5-bromo-2-pyridylazo)-5-diethylaminophenol wHg(II)-(5-Br-PADAP)x complex, at pH 9.2 mediated by micelles of the non-ionic surfactant polyethyleneglycolmono-p-nonylphenylether (PONPE 5). Cold vapor generation was developed from 100 ml of the extracted surfactant-rich phase by means of a stannous chloridep-nonylphenylether (PONPE 5). Cold vapor generation was developed from 100 ml of the extracted surfactant-rich phase by means of a stannous chlorideml of the extracted surfactant-rich phase by means of a stannous chloride (SnCl2) solution as reluctant. An exhaustive study of the variables affecting the cloud point extraction with PONPE 5 and cold vapor mercury generation from the surfactant phase was performed. The 50-ml sample solution preconcentration allowed us to raise an enrichment factor of 200-fold. The lower limit of detection obtained under the optimal conditions was 4 ng ly1. The precision for 10 replicate determinations at the 0.5-mg ly1 Hg level was 3.4% relative standard deviation (R.S.D.), calculated with the peak heights. The calibration graph using the pre-concentration system for mercury was linear with a correlation coefficient of 0.9998 at levels near the detection limits up to at least 50 mg ly1. The method was successfully applied to the determination of mercury in tap water samplesSnCl2) solution as reluctant. An exhaustive study of the variables affecting the cloud point extraction with PONPE 5 and cold vapor mercury generation from the surfactant phase was performed. The 50-ml sample solution preconcentration allowed us to raise an enrichment factor of 200-fold. The lower limit of detection obtained under the optimal conditions was 4 ng ly1. The precision for 10 replicate determinations at the 0.5-mg ly1 Hg level was 3.4% relative standard deviation (R.S.D.), calculated with the peak heights. The calibration graph using the pre-concentration system for mercury was linear with a correlation coefficient of 0.9998 at levels near the detection limits up to at least 50 mg ly1. The method was successfully applied to the determination of mercury in tap water samplesy1. The precision for 10 replicate determinations at the 0.5-mg ly1 Hg level was 3.4% relative standard deviation (R.S.D.), calculated with the peak heights. The calibration graph using the pre-concentration system for mercury was linear with a correlation coefficient of 0.9998 at levels near the detection limits up to at least 50 mg ly1. The method was successfully applied to the determination of mercury in tap water samples(R.S.D.), calculated with the peak heights. The calibration graph using the pre-concentration system for mercury was linear with a correlation coefficient of 0.9998 at levels near the detection limits up to at least 50 mg ly1. The method was successfully applied to the determination of mercury in tap water samplesmg ly1. The method was successfully applied to the determination of mercury in tap water samples