A Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS)
pretreatment
technique combined with HPLC–MS/MS was established to detect
26 pesticides in traditional Chinese medicinal leeches. The sample
was extracted by acetonitrile solution with sodium acetate-0.1% (v/v)
acetic acid as a buffer system, then cleaned up by a mixture of 750
mg of MgSO4, 150 mg of C18, and 150 mg of PSA,
separated by an ACQUITY BEH C18 column, and determined
in the dynamic multiple reaction mode. Under the optimized conditions,
the peak areas of the 26 pesticides in leeches showed good linearity
(r > 0.99) between their mass concentrations from
1 to 100 μg/L. At the spike levels of 10, 20, and 100 μg/kg,
the recoveries of 26 pesticides in leeches were 72.9–101.6%
with an RSD of 1.1–12.8%, an LOQ of 10 μg/kg, and an
LOD of 0.1–5.4 μg/kg. This method is easy, rapid, sensitive,
and practical and meets the requirements of pesticide residue detection
standards.