高效液相色谱-荧光检测法同时分析沼液中4种喹诺酮类抗生素

通过对沼液样品预处理过程优化、提取剂与洗脱剂的筛选和检测色谱条件优化,建立了固相萃取-高效液相色谱-荧光检测法分析沼液中4种喹诺酮类抗生素(FQs)的检测方法。该方法选用Na2EDTA溶液作为提取剂,调节样品pH=4,漩涡混匀后经HLB固相萃取柱净化,选用6 m L甲醇为洗脱剂,浓缩后用高效液相色谱-荧光分析法(HPLC-FLD)检测,采用乙腈/0.01 mol·L~(-1)四丁基溴化铵作为流动相,外标法定量。4种FQs在0.002~5.0 mg·L~(-1)浓度范围内呈现良好线性关系,R~2均大于0.990。样品在0.1、0.2、0.5、1.0、2.0、5.0 mg·L~(-1)6个添加水平下的平均回收率在80.4%~105.7%,相对标准偏差为1.0%~5.1%,方法的检出限为0.004~0.01 mg·L~(-1)。应用该方法对南京地区分别以鸡粪、猪粪、牛粪为发酵原料的3个大中型沼气工程的沼液样品进行分析,4种喹诺酮类抗生素均被检出,检测浓度为5~204μg·L~(-1),表明沼液中抗生素污染问题值得关注。

Simultaneous determination of four fluoroquinolones in biogas slurry by high performance liquid chromatography with fluorescence detection

An analytical method for simultaneous determination of four fluoroquinolones(FQs)in biogas slurry based on solid-phase extrac-tion and high performance liquid chromatography with a fluorescence detection(HPLC/FLD)was developed in this study. The homogenized sample adjusted to pH=4 was extracted with Na2EDTA solution, purified by Oasis HLB solid phase extraction after vortexing, and eluted with 6 mL methanol solvent. The FQs in the extract were determined by HPLC/FLD with acetonitrile and 0.01 mol·L-1 tetrabutylammonium bro-mide as mobile phases. Quantitation was carried out using an external standard method. The standard curves for all the compounds were lin-ear over the concentration ranges of 0.002 mg·L-1 to 5.0 mg·L-1 with all correlation coefficients above 0.990. The spiked recoveries at six levels of 0.1, 0.2, 0.5, 1.0, 2.0 mg·L-1 and 5.0 mg·L-1 were ranged from 80.4%to 105.7%, and the relatives standard deviations(RSD)were in the ranges of 1.0%to 5.1%. The limits of detection were from 0.004 mg·L-1 to 0.01 mg·L-1. This method was used to analyze four FQs in biogas slurry samples fermented with chicken dung, pig dung, and cow dung collected from 3 large and medium-sized biogas projects in Nanjing. Four FQs were detected in all samples, with concentrations ranging from 5μg·L-1 to 204μg·L-1, four kinds of FQs were detected. Therefore, antibiotic pollution problems in biogas slurry deserve attention.