HF-LLLME-CE法测定偶氮染料氧化降解生成的有机酸  

Determination of Organic Acids Generated from Degraded Azo Dyes by Three Phase Liquid Phase Microextraction with Capillary Chromatography

作　　者：李海燕[1,2] 龚丹[1] 刘红玉[1] 

机构地区：[1]武汉纺织大学化学与化工学院 [2]纺织印染清洁生产教育部工程研究中心,湖北武汉430073

出　　处：《环境科学与技术》2012年第7期142-146,共5页Environmental Science & Technology

基　　金：国家自然科学基金项目资助(50978208)

摘　　要：采用纤维膜三相液相微萃取(HF-LLLME)和毛细管电泳技术,对偶氮染料氧化降解过程中可能产生的小分子羧酸甲酸、乙酸、草酸、乳酸、丁二酸、柠檬酸、苹果酸进行了测定。以pH值为7.2的230 mmol/L磷酸二氢钠、115 mmol/L四硼酸钠和0.5 mmol/L十六烷基三甲基溴化铵(CTAB)溶液为缓冲液,分离电压-12 kV,检测波长200 nm的条件下,10 min内达到基线分离。三相液相微萃取以磷酸三丁酯(TBP)为有机相,供体相pH为2.5,接收相pH为12.0,萃取时间为45 min,将萃取接收相直接进行毛细管电泳(CE)测定,富集倍数在7~67之间。样品相中7种有机酸的质量浓度在5 mg/L^1 000 mg/L的范围内与电泳峰面积呈良好线性(r2>0.999 1),方法的检出限为0.09 mg/L^0.54 mg/L。运用该法对TiO2光催化降解偶氮染料过程中产生的有机酸进行测定,检测到的4种羧酸的投加回收率在93%~110%之间。A noval method of capillary electrophoresis（CE）coupled with hollow fiber three phase liquid phase microextraction（HF-LLLME）was developed for determination of 7 low molecular mass organic acids including formic acid,acetic acid,oxalate,succinic acid,citric acid,malic acid,tartaric acid and lactic acid which may be the degradation products of Reactive Brilliant Red X-3B.Baseline separation of 7 organic acids was achieved within 10 min by using 230 mmol/L NaH2PO4,115 mmol/L Na2B4O7 and 0.5 mmol/L CTAB at pH 7.2 with a constant temperature of 25 ℃,detection wavelength 200 nm and separation voltage-12 kV.Under the optimized LPME condition,tri-butyl-phosphate（TBP）as organic phase,donor phase pH 2.5,acceptor phase pH 12.0,without addition of salt,an enrichment factors ranged from 7 to 67 could be achieved within 45 min extraction.The receiving phase could be used for capillary electrophoresis analysis without any further treatment.Calibration curves for 7 organic acids were well correlated within the range of 5 mg/L^1 000 mg/L,and detection limits were in the range of 0.09 mg/L^0.54 mg/L.This proposed method was validated in analyzing organic acids produced from TiO2/UV degradation of azo dye Reactive Brilliant Red X-3B,and the spiked recoveries ranged from 93% to 110%.

关 键 词：三相液相微萃取 毛细管电泳 有机酸 偶氮染料 降解 

分 类 号：X830.2[环境科学与工程—环境工程]