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Wu Y.,Shanghai JiaoTong University | Wang Y.,Shanghai JiaoTong University | Gu X.,Shanghai JiaoTong University | Zhang L.,Shanghai JiaoTong University | And 2 more authors.
Journal of Separation Science | Year: 2011

A 2-D separation platform was constructed using micro strong cation-exchange liquid chromatography (μ-SCXLC) and reversed-phase pressurized capillary electrochromatography (RP-pCEC) for the analysis of complex samples. Samples were fractionated by the first-dimension μ-SCXLC with a linear solvent gradient and then injected into the second-dimension RP-pCEC for further separation. The μ-SCXLC/RP-pCEC 2-D system with three separation mechanisms, namely strong cation-exchange, reversed-phase chromatography and electrophoresis, provided high selectivity, high resolution and high peak capacity compared to one-dimensional chromatographic approaches. Separation effectiveness of this 2-D system was demonstrated by the analysis of different kinds of complex samples, such as traditional Chinese medicine Cortex Phellodendri, bovine serum albumin (BSA) tryptic digest and real serum tryptic digest. A theoretical peak capacity of approximately 1200 was achieved, which proves its promising potential for the separation and analysis of complex samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Zhou J.,Shanghai JiaoTong University | Zhang L.,Shanghai JiaoTong University | Zhang L.,Unimicro Shanghai Technologies Co. | Wang Y.,Shanghai JiaoTong University | Yan C.,Shanghai JiaoTong University
Journal of Separation Science | Year: 2011

A simple, rapid and reliable reversed-phase ion-pair chromatography method by HPLC coupled to an evaporative light scattering detector (ELSD) has been developed to simultaneously determine chloride, spectinomycin and its related substances in a sample. The column was a TSKgel ODS-100V. The mobile phase was ACN/aqueous solution of 15 mM ammonium acetate adjusted with TFA to pH 3.0 (2:98 v/v), in an isocratic mode. The drift tube temperature was set at 50°C and the nebulizing gas flow rate of air was 3.5 L/min for ELSD detection. Almost all of the reported degradation compounds of spectinomycin such as actinamine, actinospectinoic acid and biosynthesis intermediates such as dihydrospectinomycin diastereoisomers were baseline separated. MS was utilized for the identification of spectinomycin and its seven related substances. The method for the assay of spectinomycin was successfully validated with respect to accuracy, precision (RSD less than 2%), linearity (throughout the linear range 0.025-3 mg/mL, r=0.9993), sensitivity (LOD: 100 ng on column) and robustness. The experimental results demonstrated that the simultaneous determination of chloride, spectinomycin and related substances is feasible in a single run, which suggests applicability in routine assays. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Liu F.,Shanghai JiaoTong University | Wang Y.,Shanghai JiaoTong University | Wang Y.,Unimicro Shanghai Technologies Co. | Wang Y.,East China Normal University | And 2 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2012

A high performance liquid chromatographic method with evaporative light scattering detection (HPLC-ELSD) was developed for the simultaneous determination of five synthetic sweeteners (acesulfame-K, saccharin sodium, sodium cyclamate, sucralose and aspartame in food. The sweeteners were extracted by 0. 1% (v/v/) formic acid buffer solution. The extract of sample was cleaned up and concentrated with solid phase extraction (SPE) cartridge. Then the sweeteners were separated on a C18 column (3 μm) using 0. 1% (v/v) formic acid buffer (adjusted to pH =3.5 with aqueous ammonia solution) -methanol (61: 39, v/v) as mobile phase, and finally detfected, by ELSD. The results showed that the reasonable linearity was achieved for all the analytes over the range of 30-1000 mg/L with the correlation coefficients (r) greater than 0.997. The recoveries for the five sweeteners ranged from 85.6% to 109.0% at three spiked concentrations with the relative standard deviations (RSDs) lower than 4. 0%. The limits of detection (LODs, S/N=3) were 2. 5 mg/L for both acesulfame-K and sucralose, 3 mg/L for saccharin sodium, 10 mg/L for sodium cyclamate, and 5 mg/L for aspartame. The method is simple, sensitive and low cost, and has been successfully applied to the simultaneous determination of the five synthetic sweeteners in food. © 2010 Editorial Office of Chinese Journal of Chromatography, Dalian Institute of Chemical Physics, CAS. Source

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