title: Determination of total selenium in food samples by d-CPE and HG-AFS.
abstract: A dual-cloud point extraction (d-CPE) procedure was developed for the simultaneous preconcentration and determination of trace level Se in food samples by hydride generation-atomic fluorescence spectrometry (HG-AFS). The Se(IV) was complexed with ammonium pyrrolidinedithiocarbamate (APDC) in a Triton X-114 surfactant-rich phase, which was then treated with a mixture of 16% (v/v) HCl and 20% (v/v) H2O2. This converted the Se(IV)-APDC into free Se(IV), which was back extracted into an aqueous phase at the second cloud point extraction stage. This aqueous phase was analyzed directly by HG-AFS. Optimization of the experimental conditions gave a limit of detection of 0.023μgL-1with an enhancement factor of 11.8 when 50mL of sample solution was preconcentrated to 3mL. The relative standard deviation was 4.04% (c=6.0μgL-1, n=10). The proposed method was applied to determine the Se contents in twelve food samples with satisfactory recoveries of 95.6-105.2%.
authors.affiliation: School of Public Health, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510310, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.affiliation: School of Public Health, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510310, China.
authors.forename: Yizhou
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Shandong Jining No. 1 People's Hospital, Jining, Shandong 272011, China.
authors.forename: Jinpeng
authors.initials: J
authors.lastname: Qin
authors.affiliation: School of Public Health, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510310, China.
authors.forename: Zehua
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: School of Public Health, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510310, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Li
authors.affiliation: School of Public Health, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510310, China. Electronic address: 13640216006@163.com.
authors.forename: Bingyi
authors.initials: B
authors.lastname: Yang
mesh_terms: D005506:Food Contamination / Q000032:analysis*; D012643:Selenium / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013054:Spectrophotometry, Atomic / Q000379:methods*
chemical_list: D012643:Selenium
keywords: Box-Behnken design; Dual-cloud point extraction; Hydride generation-atomic fluorescence spectrometry; Response surface methodology; Selenium