液相色谱-质谱法测定孕妇尿液中3种残留的氯霉素类抗生素

Determination of 3 residual chloramphenicols in urine of pregnant women by liquid chromatography-mass spectrometry

目的建立液相色谱-质谱法测定孕妇尿液中3种残留的氯霉素类抗生素,并进行方法学验证。方法尿液利用Oasis HLB固相萃取小柱进行净化和富集,液相分离采用SHISEIDO MG-C_(18)(100 mm×3.0 mm,3.0μm)色谱柱,流动相为乙腈-水(含0.1%甲酸),梯度洗脱。质谱采用电喷雾离子源,选择离子监测模式检测[M-H]-:氯霉素m/z 320.8、氟苯尼考m/z 355.8、甲砜霉素m/z 353.8、甲苯磺丁脲(内标)m/z 268.9。结果尿液中3种残留的氯霉素类抗生素在5~500 ng/mL范围内呈良好的线性关系(均r>0.999);批内和批间的精密度及准确度良好(RSD<8.9%,∣相对误差(RE)∣<9.3%);提取回收率为71.4%~108.5%,稳定性良好(∣RE∣<11.8%);几乎没有残留;稀释不影响测定的精密度和准确度。共检测了18份不同孕期(孕早期、孕中期和孕晚期)孕妇的尿样,大部分样品能检测到氯霉素(但浓度低于最低定量限5 ng/mL),其中少量样品能测出氟苯尼考,完全没有检测到甲砜霉素残留。结论该方法操作简便、重现性好,适用于尿液中3种氯霉素类抗生素的测定,可为氯霉素类抗生素的残留与孕妇不良妊娠结局的相关性研究提供方法学基础。

Objective To establish and verify a liquid chromatography-mass spectrometry(LC-MS)method for the determination of 3 residual chloramphenicols in the urine of pregnant women.Methods Urine was purified and concentrated by Oasis HLB solid phase extraction column,and liquid phase separation was performed on a SHISEIDO MG-C_(18)(100 mm×3.0 mm,3.0μm)column with mobile phase of acetonitrile-water(containing 0.1%formic acid)for gradient elution.Electrospray ionization source was used for MS,and ion monitoring mode was selected for detection[M-H]-:chloramphenicol m/z 320.8,florfenicol m/z 355.8,thiamphnicol m/z 353.8,and sulfonamide(internal standard)m/z 268.9.Results The 3 residual chloramphenicols in urine showed a good linear relationship in the range of 5-500 ng/mL(all r>0.999);the precision and accuracy within and between batches were good(relative standard deviation<8.9%,∣relative error[RE]∣<9.3%);the extraction recoveries ranged from 71.4%to 108.5%,with good stability(∣RE∣<11.8%),almost with no residue;dilution did not affect the precision and accuracy of the determination.A total of 18 urine samples from pregnant women of different trimesters(first trimester,second trimester,and third trimester)were tested,chloramphenicol was detected in most of the samples(but the concentration was below the minimum quantitation limit of 5 ng/mL),florfenicol was detected in a few samples,and no thiamphnicol residue was detected at all.Conclusion The present method is simple,reproducible and suitable for the determination of 3 kinds of chloramphenicols in urine.It can provide a methodological basis for the study of the correlation between chloramphenicol residues and adverse pregnancy outcomes of pregnant women.