State Key Laboratory of Food Science and Technology, Nanchang University, 235 Nanjing East Road, Nanchang 330047, PR China.
Talanta. 2012 Aug 15;97:336-42. doi: 10.1016/j.talanta.2012.04.042. Epub 2012 May 4.
A proof-of-concept for the use of oleic acid coated magnetic nanobeads (OA-MNBs) for the magnetic solid phase extraction (MSPE) of trace amounts of leuco-malachite green (LMG) from fish samples was developed. The OA-MNBs were prepared by covalently conjugating oleic acid on amino-modified magnetic polystyrene beads. The OA-MNBs were characterized with transmission electron microscopy, Fourier transform infrared spectroscopy and zeta-potential analyzer. The optimized parameters for MSPE with OA-MNBs of LMG from fish muscle involved a combination of pH 10.0 in 10% acetonitrile, 1.5 M sodium chloride as an adsorption solution, and an extraction procedure involving 6 mg OA-MNBs in 18 mL LMG adsorption solution. This was optimized for 0.5 g fish muscles with an incubation period of 10 min using 200 μL acetonitrile for elution. Using the optimized parameters, the performance of MSPE with OA-MNBs was evaluated by analyzing LMG-spiked fish extracts with liquid chromatography-mass spectrometry (LC-MS/MS) method. The results indicated that recoveries of LMG (from 0.1 to 2 ng/g) ranged from 71.2%-112.6% with relative standard deviations as low as 0.6%. Out of 57 field fish samples, eight LMG positive samples were confirmed using MSPE with OA-MNBs. Compared with traditional liquid-liquid extraction methods, the results showed that MSPE with OA-MNBs had a higher sensitivity for samples with low LMG concentration. Furthermore, the MSPE with OA-MNB took only 40 min to perform without the need for time consuming sample-pretreatment process. Therefore, MSPE with OA-MNBs holds promise for rapid, sensitive, and cost effective screening for LMG in fish samples.
从鱼类样本中痕量的隐色孔雀石绿（LMG）的磁性固相萃取（MSPE）中使用油酸包覆的磁性纳米珠（OA-MNBs）的概念验证已经开发出来。OA-MNBs 通过将油酸共价偶联到氨基修饰的磁性聚苯乙烯珠上而制备。OA-MNBs 用透射电子显微镜、傅里叶变换红外光谱和zeta 电位分析仪进行了表征。从鱼肌肉中用 OA-MNBs 进行 MSPE 的最佳参数涉及在 10%乙腈中的 pH 值 10.0、1.5 M 氯化钠作为吸附溶液，以及涉及在 18 mL LMG 吸附溶液中使用 6 mg OA-MNBs 的提取程序。在 10 分钟的孵育时间内，使用 200 μL 乙腈对 0.5 g 鱼肌肉进行洗脱，对其进行了优化。使用优化的参数，通过使用液相色谱-质谱（LC-MS/MS）方法分析 LMG 加标鱼提取物，评估了用 OA-MNBs 进行 MSPE 的性能。结果表明，LMG（从 0.1 到 2 ng/g）的回收率范围为 71.2%-112.6%，相对标准偏差低至 0.6%。在 57 个现场鱼类样本中，有 8 个样本用 OA-MNBs 进行 MSPE 证实为 LMG 阳性。与传统的液液萃取方法相比，结果表明，用 OA-MNBs 进行 MSPE 对低浓度 LMG 的样品具有更高的灵敏度。此外，用 OA-MNBs 进行 MSPE 仅需 40 分钟，而无需耗时的样品预处理过程。因此，用 OA-MNBs 进行 MSPE 有望成为鱼类样本中 LMG 的快速、灵敏和具有成本效益的筛选方法。
