Abstract

A NEW CHEMILUMINESCENCE METHOD FOR DETERMINATION OF CYROMAZINE USING LUMINOL– Ag(III) COMPLEX REACTION IN ALKALINE MEDIUM

Ting Wang, Yajuan Dong, Peiyun Chen, Ming Su, and Hanwen Sun*

ABSTRACT

A new chemiluminescence (CL) method for the determination of pesticide cyromazine is developed. The mechanism for enhancing effect of cetyl trimethyl ammonium bromide and inhibiting effect of cyromazine to the CL of Ag(III) complex–luminol in alkaline solution was proposed. The inhibition degree of CL emission was proportional to the logarithm of cyromazine concentration from 2×10–5 to 7×10–2 g/kg. The effects of the reaction conditions on CL emission and inhibition were examined. Under the optimized conditions, the detection limit (s/n=3) was 6×10–6 g/kg. Recoveries of cyromazine at spiked levels of 5×10–4, 7×10–3, and 1.05 ×10–2 g/kg ranged from 90.1 to 109%, with relative standard deviation of 1.2–2.7%. The proposed method was used for the determination of cyromazine in spiked milk and milk powder samples. Cyromazine was found in a milk powder sample, which is lower the maximum residue limit (MRL).

Keywords: Chemiluminescence; Ag(III) complex; Enhancing; Inhibition; Cyromazine; Milk.