Enantioseparation of Imazalil and Monitoring of Its
Enantioselective Degradation in Apples and Soils Using Ultrahigh-Performance
Liquid Chromatography–Tandem Mass Spectrometry
posted on 2017-04-06, 00:00authored byRunan Li, Fengshou Dong, Jun Xu, Xingang Liu, Xiaohu Wu, Xinglu Pan, Yan Tao, Zenglong Chen, Yongquan Zheng
Imazalil
is a widely used systemic chiral fungicide that is still
being employed as a racemic mixture without distinguishing the difference
between enantiomers, which often leads to its inaccurate risk assessment.
In this study, a robust and highly sensitive chiral separation method
was developed for imazalil enantiomers by ultrahigh-performance liquid
chromatography–tandem mass spectrometry and was further applied
to study the degradation dynamics of imazalil enantiomers in apples
and field soils at three sites in China. The baseline enantioseparation
for imazalil was achieved within 3.5 min on a Lux Cellulose-2 (CCMPC)
column with acetonitrile (ACN)/water (65:35, v/v) with a mobile phase
at 0.5 mL/min flow rate and a column temperature of 20 °C. The
limit of quantitation (LOQ) for each enantiomer was <0.60 μg/kg,
with a baseline resolution of approximately 1.75. The research showed
that (S)-(+)-imazalil degraded more rapidly than
(R)-(−)-imazalil in Gala apples, whereas (R)-(−)-imazalil preferentially degraded in Golden
Delicious apples. No significant enantioselectivity was observed in
OBIR-2T-47 apples and field soils from the three sites. Results of
this study provide useful references for risk assessment and the rational
use of imazalil in further agricultural produce practice.