2,4-二硝基苯肼衍生-固相萃取-液相色谱法测定环境固体基质中15种醛酮类羰基化合物的含量

Determination of 15 Aldehyde and Ketone Carbonyl Compounds in Environmental Solid Matrix by Liquid Chromatography with 2,4-Dinitrophenylhydrazine Derivatization and Solid Phase Extraction

样品10.000g中加入200mL pH 5.0的乙酸-乙酸钠缓冲溶液,翻转振荡18h,离心。取100mL提取液,加入pH 3.0的柠檬酸-柠檬酸钠缓冲溶液4mL,3.00g·L-1 2,4-二硝基苯肼(DNPH)衍生溶液(介质为乙腈)6mL,于室温超声衍生30min。将衍生后的提取液用C18固相萃取柱萃取,乙腈洗脱并定容至10mL。萃取液采用液相色谱-二极管阵列检测器测定其中15种醛酮类羰基化合物的含量。15种醛酮类羰基化合物的质量浓度在30.0~1.50×103μg·L-1内与其对应的峰面积呈线性关系,检出限(3.143s)为0.016~0.045mg·kg-1。按标准加入法进行回收试验,丙酮的回收率为39.6%~43.3%,其他醛酮类化合物的回收率为69.0%~99.4%,测定值的相对标准偏差(n=6)为5.7%~18%。

Acetic acid-sodium acetate buffer solution （pH 5. 0, 200 mL） was added to 10. 000 g of the sample, and the mixture was oscillated for 18 h and then centrifuged. The extract of 100 mL was taken and citric acid-sodium citrate buffer solution （pH 3. 0, 4 mL） and 3. 00 g·L^-1 of 2,4-dinitrophenylhydrazine （DNPH） derivatized solution （acetonitrile as solvent, 6 mL） were added, and then the mixture was derivatized ultrasonically at room temperature for 30 min. The derivatives were further extracted by C18 solid phase extraction column, eluted with acetonitrile, and the eluant was diluted to 10 mL with acetonitrile. The 15 aldehyde and ketone carbonyl compounds were determined by liquid chromatography with diode array detector. Linear relationships between values of peak area and mass concentration of 15 aldehyde and ketone carbonyl compounds were found in the same range of 30.0-1. 50×10μg·L^-1 , with detection limits ranging from 0. 016 to 0. 045 mg·kg^-1. Tests for recovery were made by standard addition method, giving results in the range of 39. 6%- 43. 3% for actone and 69. 0%--99.4% for the other aldehydes and ketones, and RSDs （n=6） ranged from 5.7% to 18%.