喷涂废水中邻苯二甲酸酯测定的优化研究

选取固相萃取GC-MS法定量检测喷涂废水中四种邻苯二甲酸酯类(PAEs),运用正交设计法,研究了pH、洗脱剂、洗脱体积、洗脱速率和水样流速对废水中PAEs回收率的影响。结果表明,pH为2.5时回收率最佳(均100%);在该pH下,洗脱剂对4种PAEs的回收率影响最大,水样流速次之,洗脱速率与洗脱体积对4种PAEs的回收率影响相对较小。样品前处理最优参数为:水样流速8mL/min、洗脱剂为乙酸乙酯、洗脱体积4mL、洗脱速率2mL/min;该条件下4种PAEs的线性范围为0.2～8.0μg/mL,相关系数均0.99,喷漆废水中平均加标回收率为61.1%～103%,相对标准偏差为3.1%～14.6%,均可满足试验要求。

Optimization of Conditions to Determine Phthalate Esters in Spray Coating Wastewater

GC-MS with solid phase extraction was selected for quantitative determination of 4 kinds of phthalates( PAEs) in spray coating wastewater, and effect of pH, eluting solvent, volume of elution, elution rate and flow rate of wastewater on recovery of PAEs in wastewater by orthogonal design were studied. Results indicated that the best recovery was obtained at pH value of 2.5. At the optimum pH conditions, orthogonal experiment results showed that eluting solvent had the greatest impact on recovery of PAEs, followed by flow rate of wastewater, volume of eluting while eluting rate had relatively small impact. The optimized conditions for sample pretreatment were flow rate of wastewater 8mL/min, eluting solvent as ethyl acetate, volume of eluting 4mL and eluting rate 2mL/min. Linear ranges of the calibration curves for 4 kinds of PAEs were from 0.2 to 8.0μg/mL, with correlation coefficient above 0.99, average recovery of spray coating wastewater samples 61.1%～103% and RSD 3.1%～14.6%, which all met the test requirement.