Rapid Determination of Phenol in Drinking Water by 4-amino Antipyrine Method

Objectives To establish a method for rapid determination of phenol in drinking water.

Methods Adding 0.4 mL of phosphoric acid to 250 mL of water samples to eliminate the interference of sulfides in water.At pH=10.0±0.2 and under the effect of potassium ferricyanide as an oxidant, phenol in drinking water was reacted with 4-amino antipyrine to form a red dye antipyrine.After extracted with chloroform, the dye was quantified by colorimetric method.

Results Comparing with the national standard method for the determination of phenol in drinking water with 4-amino antipyrine chloroform extraction spectrophotometry, there was no statistically significant difference (P > 0.05) was observed between these two methods.The detection limit of the method in this study was 0.002 mg/L.The concentration of phenol in the range of 0.002~0.10 mg/L was in a good linearity, and the correlation coefficient was r=0.9998, the relative standard deviation was 3.0%~4.9%, the recovery of standard addition was 95.7%~98.3%.

Conclusions The determination of phenol in drinking water with a chloroform extracted antipyrine dye method was simple, sensitive, rapid and accurate.