The degree of pesticides accumulation in tap water in Taejon from June 1995 to Apr 1996 was measured by Ellman's coupled enzyme assay. Since organic phosphate and carbamate pesticides specifically inhibit the neurotransmitter modulating enzyme acetylcholinesterase(AChE), the enzyme activity can be used as a diagnosis for the pesticides accumulation in water and various samples.
During the period of this study, the enzyme activity was changed almost every week. The lowest enzyme activity was 64 % of that of the control reaction and there are several days showing about 100 % enzyme activity. In general, the enzyme activity is higher in summer than other seasons especially early spring times. The pH value of tap water was very close to neutral(pH 7.0) and it seems that the enzyme activity was not affected by the small pH changes.
Either boiling of tap water or addition of NaOH solution decomposed the pesticide components.
These results show that AChE assay is a convenient, sensitive, and reliable method for detection of pesticides in water samples.

• 이봉호(대전산업대학교 공업화학과) | Bong Ho Lee
• 전종한(대전산업대학교 공업화학과) | Jong Han Chun
• 이영순(서울산업대학교 안전공학과) | Young Soon Lee