高效液相色谱-串联质谱法同时测定牛奶和奶粉中的青霉素类药物及其主要酶解代谢产物

Simultaneous determination of penicillin and their major enzymatic metabolites in milk and milk powder by high performance liquid chromatographytandem mass spectrometry

建立了液用色谱-串联质谱法同时测定牛奶和奶粉中4种青霉素（青霉素G、青霉素V、阿莫西林、氨苄西林）及其4种β-内酰胺酶酶解产物（青霉素G脱羧咪唑酸、青霉素V脱羧噻哗酸、阿莫西林脱羧噻唑酸、铤苄州林脱羧噻唑酸）残留的方法.样品采用乙腈-水提取，浓缩后经HLB柱净化，用液相色谱-串联质谱检测，外标法定量。结果表明，青霉素原药在4～200μg／L，酶解产物在10～500μg／L范围呈良好线性，线性相关系数均大于0．99；样品检出限为5～50μg／kg（S／N≥3），定量限为8～100μg／kg（S／N≥10）；对牛奶和奶粉样品分别进行3个水平的加标回收实验（n=6），牛奶中青霉素及其酶解产物的平均回收率为83.48％～96．97％，相对标准偏差为3．86％～10．87％；奶粉中青霉素及其酶解产物的平均回收率为82.70％-95．14％，相对标准偏差为3．02％～9．81％。该方法稳定、可靠，通用于牛奶和奶粉中青霉素类药物及其酶解代谢产物的测定.

A high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/ MS） method has been developed for the determination of eight compounds in milk and milk powder. They are four penicillins （penicillin G, penicillin V, amoxicillin and ampicillin） and four major β-laetamase enzymatic metabolites of them （penilloic acid G, penilloic acid V, amoxiilloic acid and ampilloic acid）. The compounds were extracted from the samples with acetonitrile and water, cleaned-up by HLB solid-phase extraction cartridges, and then detected by HPLC-MS/MS and quantified by external standard method. The linearities were satisfactory with the correlation coefficients 〉 0.99 at the mass concentrations ranging from 4 μg/L to 200 μg/L for penicillins and from 10 μg/L to 500 μg/L for enzymatic metabolites. The limits of detection and the limits of quantification were 5 -50μg/kg （S/N≥ 3 ） and 8 - 100 μg/kg （S/N ≥ 10） , respectively. The average recoveries of the eight compounds were 83.48% -96.97% in milk and 82.70% - 95. 14% in milk powder. The relative standard deviations （RSDs） in milk and milk powder were 3.86% - 10.87% and 3.02% - 9.81%, respectively. In conclusion, the established method is convenient, accurate and sensitive so that it can be applied to the deterruination of penicillin residues and enzymatic metabolites in milk and milk powder.