高效液相色谱-荧光检测法测定环境样品中的过氧化物

对高效液相色谱-荧光检测法测定过氧化氢和有机过氧化物的方法进行了改进,从而提高了方法的检测灵敏度。以氯化血红素(hemin)作催化剂进行柱后衍生反应,过氧化物将对羟基苯乙酸氧化生成能吸收荧光的二聚物，然后用荧光检测器检测。实验确定了最佳反应管温度和荧光检测波长。应用该法测定了大气和雨水样品中过氧化物的浓度。

Determination of Peroxides in Environmental Samples by High Performance Liquid Chromatography

A high performance liquid chromatographic (HPLC) method with fluorescence detection was developed for the determination of hydrogen peroxide and organic peroxides in environmental samples, and the method has been applied to peroxides detection in urban air and rain samples. The analytical sensitivity was improved. Post-column derivatization involved the oxidation of peroxides to a fluorescent dimer using p-hydroxyphenylacetic acid, a reaction catalyzed by hemin. The optimal excitation wavelength was 315 nm, while the emission wavelength was 400 nm. The temperature of the reaction coil was controlled at about 30 degrees C. Based on the ratio of signal to noise of 3, the detection limits were 4.0 x 10(-9) mol/L for hydroperoxide (H2O2), 4.1 x 10(-8) mol/L for methylhydroperoxide (MHP) and 6.7 x 10(-8) mol/L for ethylhydroperoxide (EHP) for aqueous samples. While the corresponding detection limits were 2.4 ng/m3 for H2O2, 35.2 ng/m3 for MHP, and 74.4 ng/m3 for EHP for air samples. Air samples were collected by Horibe cold trap at the temperature of about -90 degrees C. The results show that H2O2, hydroxymethyl hydroperoxide (HMHP), MHP, and EHP were the major peroxides in air, and that peroxyacetic acid (PAA) was occasionally detected. In rain samples, the two major peroxides were H2O2 and HMHP.