[Portable microelectrolyser for quantitative polarographic analysis].

Sn(IV) has a sensitive polarographic wave in the system of H2SO4-KI-VitC-V (IV). We examined the factors influencing the polarographic wave and found that the concentration of sulfuric acid and temperature were critical factors for the determination. The sensitivity of the method was increased nearly 50-fold by decreasing the concentration of sulfuric acid from 0.8 mol/L to 0.1 mol/L. The coefficient of variation (CV) percentages of the method were less than 5% and 8% for 6-7 determinations of Sn (IV) standard and sample respectively. The recovery ranged from 97.3% to 101%. The proposed method is suitable for direct determination of trace Sn (IV) in most natural water samples.

Polarography↗

PubMed1991

[Polarographic determination of sulfide in water].

Sulfide has a sensitive polarographic wave in the system of NaOH-EDTA-triethanolamine. The addition of triethanolamine to the system improved the shape of the wave and increased the sensitivity. The peak current was directly proportional to the concentration of sulfide in the range of 0.002-5.000 ppm. The detection limit for water sample was 2 ppb, and the relative standard deviation and recovery were 2.3-7.2% and 94.0-102.0%, respectively. The proposed method is simple, accurate, sensitive and reproducible.

Polarography↗

PubMed1989

[Polarographic determination of titanium in natural water].

Titanium has a very sensitive catalytic polarographic wave in the system of cupferon-hexamine-sodium sulfate at pH 6.0-6.4. The catalytic current was proportional to the content of titanium. High blank of the reagents could be improved by extraction with the system of cupferron-chloroform. For determination, samples were filtered with quantitative filter paper, but it was not necessary for drinking water samples. The filtration was acidified with HCl to 0.5% (V/V) and heated in a boiling water bath for 30 min, 5 ml sample was sufficed to most analyses. The detection limit was 0.12 microgram/L. The coefficient of variation was 8% for 6 determinations at 0.2 microgram/L. Three levels of titanium were spiked to one sample, and it was found that the recoveries were 96-101%. The proposed method was applied to rain water, well-head water, well water, tap water and river water. The content of titanium of most samples was less than 2 micrograms/L.

Polarography↗