Abstract Concentrations of HCH and DDT organochlorine insecticide residues were measured in blubber, muscle and oil samples from three specimens of river dolphins, Platanista gangetica, from the River Ganges, India. Concentrations of HCH and DDT ranged from 94 to 289 ng g?1 and from 1324 to 9388 ng g?1 on wet wt. basis respectively. Comparisons are made with other aquatic mammals and other studies on river dolphins. P. gangetica appears to exhibit similar patterns of accumulation with age and with ß-HCH and p-p′-DDE being accumulated to higher levels than other HCH isomers and parent DDT and its other metabolites, respectively. These organochlorines may pose a health risk to river dolphin populations that are already showing evidence of environmental stress. Further studies are recommended. 相似文献
A method is reported for the determination of methyl violet in the range of 10–120 nmol L?1. The method is based on the catalytic effect of silver nanoparticles (AgNPs) on the oxidation reaction of methyl violet by potassium bromate in acid medium. The reaction is followed spectrophotometrically by measuring the change in absorbance () at 620 nm using a fixed time method. The reaction variables were optimized in order to achieve highest sensitivity. The 3б criterion detection limit was 5 nmol L?1, and the relative standard deviation for ten replicate determinations at a concentration of methyl violet of 15 nmol L?1 was 0.97% (n = 10). The method was successfully applied to the determination of methyl violet in river water samples. 相似文献