固相萃取-高效液相色谱法测定尿液中敌鼠和氯敌鼠

HPLC Determination of Diphacinone and Chlorophacinone in Urine with Solid Phase Extraction

样品经Waters Oasis HLB C_(18)固相萃取小柱富集,并先后用乙酸-甲醇和氨水-甲醇的混合液洗去杂质,用甲醇-水(90+10)混合液从柱上洗脱敌鼠和氯敌鼠使净化。洗脱液在40℃氮气吹干,残渣用1.0 mL甲醇溶解,取10.0μL注入高效液相色谱仪分析测定。采用ZorbaxExtend C_(18)柱(250 mm×4.6 mm,5 μm),以乙酸铵-乙酸缓冲溶液(0.02 mol·L^(-1),pH 5.5)-甲醇(30+70)为流动相,紫外285 nm检测。结果表明:尿液中敌鼠和氯敌鼠的质量浓度在0.02～5.0 mg·L^(-1)范围内呈线性关系,回收率分别在96.0%～100.0%和92.0%～96.0%范围,日内相对标准偏差(n=6)分别小于6.2%和4.9%,日间相对标准偏差(n=18)分别小于9.8%和8.9 %。

Diphacinone （DPCN） and/or chlorophacinone （CPCN） in samples of urine were separated, enriched and purified by solid phase extraction （SPE） on Oasis HLB C18 column. The SPE procedure micro column was rinsed successively with mixtures of HOAc-CH3OH and NH3 （aq.）-CH3OH to remove impurities, and eluted with mixture of CH3OH-HzO （90＋10） to transfer DPCN and CPCN into the eluate from the column. The eluate was evaporated to dryness by N2-blowing at 40 ℃, and the residue was taken up with 1.0 mL of CH2 OH. An aliquot of 10. 0 μL was used for HPLC determination. Zorbax Extend C18 column was used as the stationary phase and a mixture of 0. 02 mol · L^-1 NH4 OAc-HOAc buffer solution （pH 5. 5） and methanol （30＋70） was used as the mobile phase. UV detection at 285 nm was adopted. Linear relationship was found in the range of 0. 02- 5. 0 mg · L^-1 for both compounds. Test for recovery was made, giving values of recovery in the range of 96. 0%-- 100. 0% （for DPCN） and in the range of 92. 0%--96.0% （for CPCN）. Values of intraday RSD/s （n=6） found were less than 6. 2% and 4.9%, interday RSD＇s （n=18） were less than 9. 8%and 8. 9% for DPCN and CPCN respectively.