title: Comparative study of hollow-fiber liquid-phase micro-extraction and an aqueous two-phase system for determination of phytohormones in soil.
abstract: Two methods, hollow-fiber liquid-phase micro-extraction (HF-LPME) and an aqueous two-phase system (ATPS), have been systematically optimized and compared for extraction and determination of phytohormones in soil by high-performance liquid chromatography (HPLC). The effects on extraction of conditions including solvent type and volume, extraction time, temperature, and amount of salt were evaluated. It was shown that ATPS was superior to HF-LPME for determination of paclobutrazol and uniconazole under the optimum conditions. The limits of detection (LODs) of ATPS were 0.002 μg g(-1) for uniconazole and 0.01 μg g(-1) for paclobutrazol, whereas LODs of HF-LPME were 0.005 μg g(-1) and 0.03 μg g(-1), respectively. Relative standard deviations (RSDs, n=5) and recovery were in the range 1.7-5.3 % and 86-102 %, respectively, for ATPS and 6.7-7.9 % and 40-60 % for HF-LPME. In addition, the advantages of ATPS were shorter extraction time, suitable for simultaneous pretreatment of batches of samples, and higher extraction capacity. ATPS was therefore applied to the determination of paclobutrazol and uniconazole in real soil samples. Uniconazole was detected in all the samples analyzed whereas paclobutrazol was not found.
authors.affiliation: College of Sciences, Xi'an University of Architecture and Technology, Xi'an 710055, China. dshiney2004@yahoo.com.cn
authors.forename: She Ying
authors.initials: SY
authors.lastname: Dong
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
authors.forename: Penghui H
authors.initials: PH
authors.lastname: Zhang
authors.forename: Qing
authors.initials: Q
authors.lastname: Hu
authors.forename: Ting Lin
authors.initials: TL
authors.lastname: Huang
mesh_terms: D002851:Chromatography, High Pressure Liquid; D057230:Limit of Detection; D059627:Liquid Phase Microextraction; D010937:Plant Growth Regulators / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010937:Plant Growth Regulators; D012989:Soil Pollutants