Development of an enzyme-linked immunosorbent assay for the detection of pentachlorophenol residues in water samples

An indirect competitive enzyme-linked immunosorbent assay (ELISA) for pentachlorophenol (PCP) was developed with a polyclonal antiserum produced against a hapten, 4-(2,3,5,6-tetrachloro-4-hydroxyphenoxy)-butyric acid, conjugated to bovine serum albumin (BSA). The ELISA of PCP showed an IC50 of 18 ng/ml and a limit of detection (LOD) of 0.9 ng/ml at the optimal concentration of NaCl (0.2 M) in the assay buffer. This assay was slightly affected by up to 10% (v/v) methanol or acetone. The IC50 and A(max) values showed little change in a pH range of 5 and 7. Very low cross reactivities (<= 2.5%) were observed for some structurally-related compounds, except for 2,3,4,6-tetrachlorophenol (5.6%) and 2,3,5,6-tetrachlorophenol (9.2%). The average recoveries of PCP from fortified water were in the range of 71-118%. The results by GC and ELISA for the same fortified water samples showed non-significant difference (p > 0.05). Finally, this ELISA was applied to monitor PCP in 100 river water samples and no PCP was detected. This ELISA is a good alternative tool for monitoring PCP residues in water samples.