GC/MS Based Non-target Screening of Organic Contaminants in River Indus and its Tributaries in Sindh (Pakistan)

Abstract

To investigate presence of organic contaminants in river Indus and its tributaries screening studies were carried out. Two years screening studies were based on four sampling campaigns in 13 sampling points out of which 9 sampling points belong to river Indus and its tributaries, 4 to municipal sewerage and 1 to industrial sewerage. Deconvolution Reporting Software (DRS) was used to analyze scan data. Deconvolution is capable of screening the compounds whose peaks become invisible due to co-extracted compounds. Furthermore it significantly reduces analysis time and chromatographic resolution requirements. Results reveal that all the sampling points were greatly polluted with phthalate esters and tributyl phosphate (TBP). Apart from these, numerous long chain hydrocarbons, toxic phenols i.e. bisphenol A, analgesic i.e. ibuprofen and mefenamic acid, pesticides i.e. endosulfan, PCPIs, etc have significantly contaminated water bodies. In this screening analysis many compounds are identified that can be possible emerging contaminants and that are rarely documented. The identified contaminants are debated in accordance with their use, possible emission source and pathway. To the best of our knowledge this study holds first detailed screening of organic contaminants in river Indus and its tributaries. The information gathered in this analysis can be useful for future studies based on individual contamination in river Indus.