Articles by Pan Gu in JoVE
A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites Li Xie1, Liqin Chen3, Pan Gu4, Lanlan Wei1, Xuejun Kang2 1School of Public Health of Southeast University, Laboratory of Environment and Biosafety Research Institute of Southeast University in Suzhou, 2Key Laboratory of Child Development and Learning Science (Ministry of Education), School of Biological Science & Medical Engineering, Southeast University, 3School of Public Health, Tianjin Medical University, 4British Columbia Academy, Nanjing Foreign Language School We present a convenient solid-phase extraction coupled to high-pressure liquid chromatography (HPLC) with electrochemical detection (ECD) for simultaneous determination of three monoamine neurotransmitters and two of their metabolites in infants' urine. We also identify the metabolite MHPG as a potential biomarker for the early diagnosis of brain damage for infants.
Other articles by Pan Gu on PubMed
Simultaneous Quantification of Cortisol and Cortisone in Urines from Infants with Packed-fiber Solid-phase Extraction Coupled to HPLC-MS/MS Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences. | Pubmed ID: 28735224 Cortisol and cortisone are two important glucocorticoids in human body, their interconversion is controlled by two isotypes of 11β-hydroxy steroid dehydrogenase (11β-HSD1 and 11β-HSD2). The ratio of urinary cortisol to cortisone can be used to assess the activity of 11β-HSDs. An analytical method to quantify urinary cortisol and cortisone using high performance liquid chromatographic tandem mass spectrometry following a packed-fiber solid-phase extraction (PFSPE) was developed. The proposed method was validated and applied to determine the urinary cortisol and cortisone concentrations in infants. Linearity was observed in the range of 0.6-150ng/mL for cortisol and 0.8-200ng/mL for cortisone. The intra-day RSD was 2.4-4.5% for cortisol and 3.3-6.2% for cortisone. Inter-day RSD was 3.7-6.6% for cortisol and 4.3-8.2% for cortisone. The recovery was 97.8±4.6% for cortisol and 98.9±4.4% for cortisone. The established method is simple and efficient for the quantification of urinary cortisol and cortisone and for indirectly assessing the activity of 11β-hydroxy steroid dehydrogenase.