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ABSTRACT: A simple and efficient method based on a novel solid phase extraction (SPE) cartridge and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) was developed for the determination of clenbuterol residue in pork. The minced pork sample was ultrasonically extracted by 5% (v/v) perchloric acid and centrifuged at 10 000 r/min for 15 min, then the supernatant was purified by an SMCX cartridge, which is a novel SPE column based on homemade silica matrix with two mixed modes of reversed-phase and strong cation exchange, for the selective enrichment and purification of the analyte. The linear range of the method was 0.25 - 50 microg/kg with a correlation coefficient of 0.998 2. The average recoveries ranged from 62.2% to 72.0% at the three spiked levels of 1.25, 12.5 and 50 microg/kg with the relative standard deviations (RSDs) between 4.2% and 6.1%. The limit of detection (S/N = 3) was 0.05 microg/kg. The method is simple, fast and can be extended to enrich and determine beta-agonist drugs.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 02/2012; 30(2):141-5.
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ABSTRACT: Two different offline 2-D hydrophilic interaction chromatography (2D-HILIC/HILIC) systems have been developed. In the two systems, a click maltose column was used in the first dimension, an amide column or a click beta-CD column was used in the second dimension, respectively. Both of the systems were used for the analysis of very polar components in Carthamus tinctorius Linn., which is a traditional Chinese medicine. Excellent orthogonality and separation results were obtained in both 2D-HILIC/HILIC systems, while the peak capacity of the system based on click maltose and amide column was higher for its adoption of stationary phase with smaller particle size in the second dimension.
Journal of Separation Science 09/2009; 32(17):2871-6. · 2.73 Impact Factor
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ABSTRACT: A novel two-dimensional reversed-phase liquid chromatography/hydrophilic interaction chromatography (2D-RPLC/HILIC) system is developed with the introduction of the click beta-cyclodextrin (beta-CD) stationary phase. The offline system shows excellent abilities for the separation of polar and medium-polarity components in traditional Chinese medicine (TCM). It facilitates us not only to separate components that cannot be resolved by uni-dimensional chromatography, but also to achieve much more efficient detection of components with low abundance. The orthogonality of this new system is excellent. A simple geometric approach is developed to characterize the practical orthogonality of 2D-LC in the analysis of complex unknown samples. The mathematical characterization results are in good accordance with the experimental findings, and both demonstrate that the proposed 2D-RPLC/HILIC system is a powerful tool for the separation of polar and medium-polarity complex samples. This system may have a great potential for the separation of peptides and metabolomic compounds with similar polarity.
Journal of Chromatography 09/2008; 1208(1-2):133-40. · 4.53 Impact Factor
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ABSTRACT: An off-line 2-D-LC approach was developed for the separation and identification of components in extracts of Swertia franchetiana Smith, which is a traditional Chinese medicine. An octadecylsilica column was used for further separation of fractions from a cyano column with UV and MS detection. In this method, a longer column was used in the second dimension to improve the separation ability, and "on-column focusing" was adopted to reduce sample loss and pollution on concentrating the fractions from the first dimension. More than 118 and 575 components were detected in the chloroform and n-butanol extracts by this method, respectively. In contrast, only 20 and 95 peaks were detected by the one-dimensional method. Most of the additionally detected compounds were of low-abundance components. Many compounds can be preliminarily identified according to their UV and mass spectra in the two-dimensional method. The obtained results not only demonstrated the powerful resolution of 2-D-LC, but also led to in-depth comprehension of the UV and mass spectra of complex samples.
Journal of Separation Science 05/2008; 31(6-7):935-44. · 2.73 Impact Factor
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ABSTRACT: A novel click oligo(ethylene glycol) (Click OEG) stationary phase was proposed for constructing two-dimensional reversed-phase/reversed-phase liquid chromatography system (2D-RP/RPLC) combined with C18. The new stationary phase was prepared by immobilization of oligo(ethylene glycol) on silica support via click chemistry. And the resulting material was characterized by FT-IR, solid state CP/MAS 13C NMR and elemental analysis. The investigation on orthogonality between Click OEG and C18 was performed by geometric approach with a set of test solutes. The orthogonality reached 68.94%, which is much higher than other combinations. An offline 2DLC system consisted of Click OEG and C18 was constructed and applied to the analysis of a kind of traditional Chinese medicine Lignum Dalbergiae Odoriferae. Excellent separation results validated the high orthogonality between the Click OEG and C18 in the practical separation of complex samples.
Journal of Chromatography A.
