建立了固相萃取-反相液相色谱-荧光检测法分析污水中壬基酚聚氧乙烯醚总量的方法。固相萃取采用Waters Oasis固HLB固相萃取柱(30μg×60mg×3mL),6mL二氯甲烷/甲醇(90/10,V/V)混合溶剂洗脱,洗脱液用氮吹仪浓缩至1mL,回收率为99.68%。采用ZORBAX Eclipse XDBC-18(4.6mm×150mm,5μm)反相色谱柱,甲醇/水为流动相,流速1.0mL/min,以每分钟增加2.5%的梯度陡度进行洗脱,流动相中甲醇比例由70%增加到100%,柱温23℃,进样量15μL。荧光检测器的激发波长230nm,发射波长313nm。采用外标法定量。该方法的空白加标和污水样品加标回收率均在90%以上,标准偏差小于10%,定量下限为0.97~1.90μg/L。利用该方法分别对污水处理厂进水水样、二级处理出水水样、再生水水样进行了测定,测定结果的准确度和精密度满足痕量分析的要求。
A new method based on solid phase extraction-reversed phase liquid chromatography-fluorescence detector (SPE-RPLC-FLD) is established for the quantitative determination of nonylphenol polyethoxylates (NPnEO) in sewage. The method is under the condition of Waters Oasis HLB solid phase extraction column (30μg ×60 mg ×3 mL), eluted by 6 mL dichloromethane/methanol(90/10,V/V), then vaporized to 1 mL by faint nitrogen gas. The recovery rate of pretreatment sample process is 99.68%. NPEO(n = 10) are detected by ZORBAX Eclipse XDBC-18(4.6 mm × 150 mm,5μm) column; methanol/water is adopted as mobile phase at a flow rate at 1.0 mL/min; gradient eluted is set at 2.5% per minute, the proportion of methanol in water is increased from 70% to 100% gradually; the oven temperature is 23 ℃ ; injection volume is 15μL. The excitation length is 230 nm and the emission length is 313 nm and for FLD. External standard calibration method is chosen as quantitative method. The recovery rate for NPnEO(n = 10) in sewage and blank sample is both above 90% , relative standard deviation is below 10% , the detection limit of NPnEO(n = 10) is 0.97 - 1.90μg/L. By this method, NPEO (n = 10) concentrations of some wastewater samples are analyzed. The accuracy and precision of the results are satisfactory.