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Zhang L.,Hebei Medical University | Zhang F.,Air Force General Hospital | Wang Z.,Institute of Forensic Science of Supreme Peoples Procuratorate | Jiang Y.,Hebei Medical University | And 2 more authors.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui | Year: 2013

A rapid and sensitive method has been developed for the simultaneous determination of ephedrine and N-methylephedrine in urine samples by solid phase extraction-ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (SPE-UPLC-ESI MS/MS). The samples were extracted with Oasis MCX solid phase extraction cartridges and measured in the modes of electrospray positive ionization (ESI +) and multiple reaction monitoring (MRM). Good linearities were observed in the range of 0.025 0 - 2.50 microg/L with correlation coefficient over 0.999 0 for both analytes. The recoveries were above 80% with RSDs less than 5.0%. The limits of detection were 0.01 microg/L. The method proves to be rapid and sensitive for the trace determination of ephedrine and N-methylephedrine in urine samples.


Li Q.,Hebei Medical University | Jing S.,Hebei Medical University | Zhang J.,Hebei Medical University | Zhang L.,Institute of Forensic Science of Supreme Peoples Procuratorate | And 3 more authors.
Analytical Methods | Year: 2015

A sensitive and reliable method using a two-phase hollow fiber liquid-phase microextraction (HF-LPME) pretreatment technique was developed for simultaneously screening multiple β-blockers in environmental samples. In this study, heptanol was chosen as the optimal extraction solvent, and six β-blockers with a wide range of polarities were extracted across the porous walls of hollow fibers and into the acceptor phase (AP). The fundamental parameters affecting the extraction efficiency (EE) of analytes including extraction time, temperature, pH of the donor phase (DP) and AP, stirring speed, volume of the sample solution, ionic strength and the type of hollow fiber membrane were studied and optimized. Under optimal conditions, extracts were analyzed by HPLC with ultraviolet detection (UV). Finally, satisfactory results were obtained, good linearity was observed for all β-blockers in the range of 0.16-200 ng mL-1, limits of detection (LODs) were between 0.08 and 0.5 ng mL-1, the intra- and inter-day precision values of the six β-blockers were 1.0-2.2% and 1.4-2.7%, respectively. The recovery with RSDs was less than 2.2% for the pretreatment method. The proposed technique was successfully applied for screening multiple β-blockers in complex aqueous samples with the best specificity and provided a simple and reliable new means for the self-checking of laboratories at the basic level. This journal is © The Royal Society of Chemistry 2015.


Zhang P.,Hebei Medical University | Zhang P.,Hebei Key Laboratory of Forensic Medicine | Zhang F.,Air Force General Hospital | Wang Z.,Institute of Forensic Science of Supreme Peoples Procuratorate | And 3 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2013

A rapid, specific and sensitive ultra performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of four trace alkaloids, including aeonitine (AC), hypaconitine (HA), mesaconitine (MA) and yunaconitine (YA) in human urine samples. UPLC-MS-MS system coupled with an electrospray ionization (ESI) source wasrperformed in multiple reaction monitoring (MRM) mode. The sample preparation was performed with hollow fiber microextraction (HF-LPME) prior to the analysis^ The enrichment factors of the four alkaloids were 102 - 301. The separation was applied on a Waters ACQUITY UPLC BEH C18 column (50 mm x2. 1 mm, 1. 7 μm) with a gradient elution of acetonitrile and 10 mmol/L NH4HCO3 as mobile phase. The retention times were less than 3 min. This method significantly improved the detection sensitivity, and the limits of quantitation were from 0. 01 to 0. 1 ng/L. The calibration curves were linear over the ranges of 0. 01 - 10 ng/L for AC, MA and YA, 0. 1 - 100 ng/L for HA in human urine samples, and the correlation coefficients were 0. 998 1, 0. 998 4, 0. 999 5 and 0. 998 6, respectively. The method was proved to be rapid and sensitive for aconitum alkaloid analysis in urine samples.


Li Q.-L.,Hebei Medical University | Jing S.-J.,Hebei Medical University | Zhang J.-F.,Hebei Medical University | Zhang L.,Institute of Forensic Science of Supreme Peoples Procuratorate | And 3 more authors.
Journal of Separation Science | Year: 2015

The selectivity of a suitable organic solvent is key for extraction in liquid-phase microextraction experiments. Nevertheless, the screening process remains a daunting task. Our research aimed to study the relationship between extraction efficiency and extraction solvents, analytes, and finally select the appropriate extraction solvent. In the present article, β-blockers and six extraction solvents were chosen as the models and hollow-fiber liquid-phase microextraction was conducted. The relationship was built by statistical analysis on the data. Factors affecting extraction efficiency including the logarithms of the octanol/water partition coefficient (logPo/w) of analytes, acid dissociation constants, the logarithms of the octanol/water partition coefficient of solvents and pH of the sample solution were investigated. The results showed that a low water solubility of extraction solvent is the foundation to ensure higher extraction efficiency. Moreover, when ΔlogPo/w > 0, a higher extraction efficiency is observed at lower ΔlogPo/w, on the contrary, when ΔlogPo/w < 0, extraction efficiency is higher as the absolute value of ΔlogPo/w becomes greater. Finally, the relationship between enrichment factor and extraction solvents, analytes was established and a helpful guidance was provided for the selection of an optimal solvent to obtain the best extraction efficiency by liquid-phase microextraction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhang L.,Hebei Medical University | Zhang F.,Air Force General Hospital | Wang Z.,Institute of Forensic Science of Supreme Peoples Procuratorate | Jiang Y.,Hebei Medical University | And 2 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2013

A rapid and sensitive method has been developed for the simultaneous determination of ephedrine and iV-methylephedrine in urine samples by solid phase extraction-ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (SPE-UPLC-ESI MS/MS). The samples were extracted with Oasis MCX solid phase extraction cartridges and measured in the modes of electrospray positive ionization (ESI+) and multiple reaction monitoring (MRM). Good linearities were observed in the range of 0. 025 0-2.50 μg/L with correlation coefficient over 0.999 0 for both analytes. The recoveries were above 80% with RSDs less than 5. 0%. The limits of detection were 0. 01 μg/L. The method proves to be rapid and sensitive for the trace determination of ephedrine and iV-methylephedrine in urine samples.


Zhang P.-P.,Hebei Medical University | Zhang J.-Z.,Hebei Medical University | Wang Z.-H.,Institute of Forensic Science of Supreme Peoples Procuratorate | Lu Y.-J.,Juxian County Hospital of Traditional Chinese Medicine | Jiang Y.,Hebei Medical University
Zhongguo Zhongyao Zazhi | Year: 2013

To establish a method for the content determination of indexes for measuring aconitic compounds contained in Shenfu injection, in order to provide basis for the evaluation of the curative effect of monkshood in Shenfu injection. The sample were purified and enriched with HF-LPME. ACQUITY UPLC BEH C18 column (2.1 mm×50 mm, 1.7 μm) was adopted and eluted with a gradient program, with acetonitrile-10 mmol·L-1NH4HCO3(pH 10) as the mobile phases. The flow rate was 0.45 mL·min-1. The content was determined with ESI and MRM. The results showed that aconitine, hypaconitine and mesaconitine showed a good linear relationship, with r>0.999, within the range of 0.1-100 ng·L-1. The recoveries were detected to be 100.1%, 97.4%, 97.5%, with RSD being 1.2%, 1.1%, 1.5%, respectively. This method was used to prove the safety of Shenfu injection, and provide scientific basis for correct evaluation of curative effect of monkshood, as well as a reliable, simple and practical means for quality control of monkshood-containing Chinese materia medica preparations.


PubMed | Institute of Forensic Science of Supreme Peoples Procuratorate and Hebei Medical University
Type: Journal Article | Journal: Journal of separation science | Year: 2015

The selectivity of a suitable organic solvent is key for extraction in liquid-phase microextraction experiments. Nevertheless, the screening process remains a daunting task. Our research aimed to study the relationship between extraction efficiency and extraction solvents, analytes, and finally select the appropriate extraction solvent. In the present article, -blockers and six extraction solvents were chosen as the models and hollow-fiber liquid-phase microextraction was conducted. The relationship was built by statistical analysis on the data. Factors affecting extraction efficiency including the logarithms of the octanol/water partition coefficient (logPo/w ) of analytes, aciddissociation constants, the logarithms of the octanol/water partition coefficient of solvents and pH of the sample solution were investigated. The results showed that a low water solubility of extraction solvent is the foundation to ensure higher extraction efficiency. Moreover, when logPo/w > 0, a higher extraction efficiency is observed at lower logPo/w , on the contrary, when logPo/w < 0, extraction efficiency is higher as the absolute value of logPo/w becomes greater. Finally, the relationship between enrichment factor and extraction solvents, analytes was established and a helpful guidance was provided for the selection of an optimal solvent to obtain the best extraction efficiency by liquid-phase microextraction.


PubMed | Institute of Forensic Science of Supreme Peoples Procuratorate, Interpol Corps of Yunnan Public Security Bureau, Hebei Medical University and Air Force General Hospital
Type: Journal Article | Journal: Se pu = Chinese journal of chromatography | Year: 2014

A rapid and sensitive method has been developed for the simultaneous determination of ephedrine and N-methylephedrine in urine samples by solid phase extraction-ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (SPE-UPLC-ESI MS/MS). The samples were extracted with Oasis MCX solid phase extraction cartridges and measured in the modes of electrospray positive ionization (ESI +) and multiple reaction monitoring (MRM). Good linearities were observed in the range of 0.025 0 - 2.50 microg/L with correlation coefficient over 0.999 0 for both analytes. The recoveries were above 80% with RSDs less than 5.0%. The limits of detection were 0.01 microg/L. The method proves to be rapid and sensitive for the trace determination of ephedrine and N-methylephedrine in urine samples.

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