摘要
以1-(2-噻唑偶氮)-2-萘酚(TAN)为络合试剂,非离子表面活性剂Triton X-114为萃取剂,浊点萃取同时富集Cr(Ⅲ)和Cr(Ⅵ),并于RP-C18柱上,用含4.5 mmol/L十六烷基三甲基溴化铵(CTMAB)和0.03mol/L HAc-NaAc缓冲溶液(pH5.5)的甲醇-水(体积比69∶31)溶液为流动相,对富集的Cr(Ⅲ)和Cr(Ⅵ)进行高效液相色谱快速分离、测定。对浊点萃取时溶液的pH值、TAN和Triton X-114的用量等影响因素进行了考察。在优化实验条件下,对100μg/L的Cr(Ⅲ)和Cr(Ⅵ)进行7次平行测定,保留时间的相对标准偏差分别为1.2%和0.9%,峰面积的相对标准偏差分别为4.7%和2.7%。Cr(Ⅲ)和Cr(Ⅵ)的线性范围均为50~5 000μg/L,检出限分别为7.5、3.5μg/L。大部分离子不干扰测定,该方法具有较高的灵敏度,可用于湖泊表层沉积物中铬形态的分析。
A cloud point extraction(CPE) was applied for simultanous preconcentration of chromium speciation in lake sediments by using 1-(2-thiazdylazo)-2-napthol(TAN) as chelating agent and nonionic surfactant octylphenoxypolyethoxyethanol(Triton X-114) as the extractant.The separation of TAN chelates of Cr(Ⅲ) and Cr(Ⅵ) was performed by high-performance liquid chromatography(HPLC) with RP-C18 column using a mixture of methanol-water(69∶31,by volume) containing 4.5 mmol/L cetyltrimethylammonium-bromide(CTMAB) and 0.03 mmol/L NaAc-HAc buffer(pH 5.5) as the mobile phase at a flow rate of 0.8 mL·min-1.The experimental affecting factors,such as pH,Triton X-114 and TAN concentration,were investigated.Under the optimized conditions,the relative standard deviations(RSDs,n=7) for 100 μg/L of Cr(Ⅲ) and Cr(Ⅵ) mixture were 1.2% and 0.9% for the retention time,4.7% and 2.7% for the peak area,respectively.The linear ranges of Cr(Ⅲ) and Cr(Ⅵ) were in the range of 50-5 000 μg/L with detection limits of 7.5 and 3.5 μg/L,respectively.Most of common coexisting ions did not effect on the determination of Cr(Ⅲ) and Cr(Ⅵ).The proposed method was applied in the speciation analysis of chromium in lake surface sediment samples with satisfactory results.
出处
《分析测试学报》
CAS
CSCD
北大核心
2010年第12期1125-1129,共5页
Journal of Instrumental Analysis
基金
国家"水体污染控制与治理"重大专项资助项目(2008ZX07103-002-005&2008ZX07010-003-001)
国家科技部国际科技合作项目(2008DFA91310&2009DFA93030)
安徽省科技攻关计划项目(08010302110)
关键词
浊点萃取
铬形态
高效液相色谱
沉积物
巢湖
cloud point extraction
chromium speciation
high-performance liquid chromatography
sediment
Chaohu lake