Perchlorate, chlorate and bromate in water samples from the South-West coast of India

Abstract

Occurrence of perchlorate (ClO4-), chlorate (ClO 3-) and bromate (BrO3-) in public drinking, open well and surface water sources at 20 locations in the South-West coastal state of Kerala (India) is reported. The analysis was performed by high performance liquid chromatography interfaced with tandem mass spectrometry (HPLC-MS/MS). Irrespective of water source (public tap water, open well water and surface water) all the analyzed samples contained high levels of ClO 4-, indicating its contamination throughout the region. The highest ClO4- level found was 91.4 μg/L, which is 3.7 times higher than US EPA recommendations. ClO3- and BrO3- were also detected in the samples, with highest concentrations of 177 and 5.34 μg/L respectively in tap water samples. Regression analysis showed moderate positive correlation between ClO 4- and bromide (Br-) in tap water (r 2=0.659) and open well water (r2=0.485) samples, respectively. Similar correlation was also observed between ClO4- and Cl- (r2=0.591) concentrations in well water samples, indicating sea water could be one of the probable sources in addition to ClO4- manufacturing in the area. This is the first report of high levels of ClO4- and ClO 3- and detectable BrO3- in water samples from anywhere in India. © IWA Publishing 2012.