正丙醇/硫酸铵双水相萃取-高效液相色谱-串联质谱法测定印染废水中的7种分散染料的含量

取含分散染料的废水样品5.00mL,用由正丙醇200μL和硫酸铵2.75g组成的萃取剂体系进行双水相超声提取21min。离心5min后,分取上层有机相50μL,吹氮蒸干。用CH_3CN-H_2O(7+3)混合液100μL溶解残渣。此溶液引入作为固定相的Zorbax Eclipse XDB-CN色谱柱,并用0.1%(体积分数)甲酸溶液和乙腈(3+7)混合液为流动相进行梯度洗脱。用MS/MS测定其中7种分散染料的含量。质谱分析中采用电喷雾离子源及多反应监测模式。所测定的7种分散染料的质量浓度在一定范围内与其峰面积呈线性关系,7种染料的检出限(3S/N)在3.3～57ng·L^-1之间。以印染废水样品为基质,按标准加入法进行回收试验,测得回收率在80.0%～116%之间,测定值的相对标准偏差(n=5)在1.2%～10%之间。

HPLC-MS/MS Determination of 7 Disperse Dyes in Printing and Dyeing Wastewater with Separation by Bi-Aqueous Phase Extraction Using n-Propanol and Ammonium Sulfate as Extraction System

5.00 mL of the wastewater sample were taken and extracted ultrasonically for 21 min by biaqueous phase extraction with extractant system composed of 200μL of n-propanol and 2.75 g of(NH4)2SO4.After centrifuging for 5 min,50μL of the upper organic phase was taken and evaporated to dryness by N2-blowing.The residue was dissolved with 100μL of CH3CN-H2O(7+3)mixture,and the solution was then separated by HPLC using Zorbax Eclipse XDB-CN column as stationary phase and a mixture of 0.1%(φ)formic acid solution and acetonitrile(3+7)was used as mobile phase for elution.MS/MS with ESI,MRM was adopted for determination of the 7 disperse dyes.As shown by the results,linear relationships between values of peak area and mass concentration of the 7 disperse dyes were found in definite ranges,with detection limits(3 S/N)in the range of 3.3-57 ng·L^-1.Test for recovery by standard addition method was made using wastewater from printing and dyeing process as matrix,giving results in the range of 80.0%-116%,and RSDs(n=5)ranged from 1.2% to10%.