U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania 19038, USA.
J Agric Food Chem. 2010 Jun 23;58(12):7109-14. doi: 10.1021/jf9043925.
Residues of malachite green (MG), gentian violet (GV), and their leuco metabolites in channel catfish muscle were individually determined by HPLC using diode array and fluorescence detectors and confirmed by tandem mass spectrometry. This detection scheme obviates a PbO(2) reactor that converts leuco forms to chromatic forms for absorbance detection, therefore eliminating uncertainties in oxidant depletion and data integrity. Extraction was performed once in pH 3 McIlvaine buffer and acetonitrile, followed by cleanup using a polymeric strong cation-exchange column. Liquid-liquid extraction was excluded to provide an environmentally responsible and relatively rapid protocol. Spectrometric limits of detection (LOD; S/N = 3) for MG (lambda = 620 nm) and GV (lambda = 588 nm) were 0.38 and 0.26 ng/g with 44.5-49.2% and 92.2-101.4% recoveries (1-10 ng/g, n = 6), respectively. Fluorometric LOD (S/N = 3) for LMG and LGV (lambda(ex) = 266 nm, lambda(em) = 360 nm) were 0.10 and 0.09 ng/g with 74.3-84.5% and 80.6-86.5% recoveries (1-10 ng/g, n = 6), respectively. This simplified protocol saves costs and meets the sensitivity requirements set by the Food and Drug Administration and the European Union.
孔雀石绿（MG）、结晶紫（GV）及其无色代谢物在斑点叉尾鮰肌肉中的残留量分别采用二极管阵列和荧光检测器的 HPLC 法进行测定，并通过串联质谱法进行确证。该检测方案省去了将无色形式转化为显色形式进行吸光度检测的 PbO(2) 反应器，从而消除了氧化剂消耗和数据完整性方面的不确定性。提取方法为一次在 pH 3 的 McIlvaine 缓冲液和乙腈中进行，然后使用聚合型强阳离子交换柱进行净化。排除了液液萃取，以提供一种对环境负责且相对快速的方案。MG（λ=620nm）和 GV（λ=588nm）的光谱检测限（LOD；S/N=3）分别为 0.38 和 0.26ng/g，回收率为 44.5-49.2%和 92.2-101.4%（1-10ng/g，n=6）。LMG 和 LGV（λ(ex)=266nm，λ(em)=360nm）的荧光检测限（LOD；S/N=3）分别为 0.10 和 0.09ng/g，回收率为 74.3-84.5%和 80.6-86.5%（1-10ng/g，n=6）。该简化方案节省了成本，并满足了美国食品和药物管理局和欧盟设定的灵敏度要求。
