牛奶中氯霉素的纳米纤维固相萃取快速前处理方法

将纳米纤维固相萃取柱应用于氯霉素检测的前处理，建立牛奶中氯霉素检测的快速前处理方法。在样液中加入高氯酸沉淀蛋白，离心后取上清液调节pH值至中性后直接过柱，100μL甲醇洗脱得洗脱液，取20μL注入高效液相色谱仪检测。流动相为甲醇:Na2HPO4-柠檬酸缓冲液(1:2，V/V，pH3.8)，流速1.0mL/min，紫外检测波长277nm。优化高氯酸体积分数、上清液的pH值、盐质量浓度、洗脱剂用量。在最优条件下，方法定量线性范围为0.05～10μg/mL。方法回收率为92.3%～105.3%，日内RSD为2.5%～8.9%，日间RSD为11.7%。与C18固相萃取柱相比，本方法操作简便，效率高，且精密度高，回收率好，是一种可靠并且相对高效环保的方法，可应用于牛奶中氯霉素的检测。

Packed-Nanofiber Solid Phase Extraction as Rapid Sample Pretreatment for HPLC Determination of Chloramphenicol in Milk

A rapid HPLC method was established for the determination of chloramphenicol based on packed-nanofiber solid phase extraction. Samples were added with HClO4 for protein precipitation. The centrifugal supernatant was collected, adjusted to pH 7 and directly loaded onto a packed-nanofiber solid phase extraction column; afterwards, 100 μL of methanol was used to elute the column and 20 μL of the pooled eluate was injected into an HPLC system. The mobile phased used was Na2HPO4-citirci acid buffer (1:2, V/V, pH 3.8) at a flow rate of 1.0 mL/min. The detection wavelength was set as 277 nm. Perchloric acid concentration, pH and ionic strength of centrifugal supernatant and eluent volume were optimized. Under optimized conditions, the linear quantification range of the HPLC method was 0.05–10 μg/mL. Average recovery rates of chloramphenicol from spiked blank milk samples across three spiking levels were in the range of 92.3%–105.3% with an intra-day assay RSD between 2.5% and 8.9% and an inter-day assay RSD of 11.7% (n = 5). This method was more simple and efficient and showed higher precision and recovery compared with C18 column extraction. Hence it can used to determine chloramphenicol residue in milk as a reliable, efficient and environment-friendly method.