Wei-Chih Cheng |
------>authors3_c= ------>paper_class1=1 ------>Impact_Factor=2.772 ------>paper_class3=2 ------>paper_class2=1 ------>vol=23 ------>confirm_bywho=shtsai ------>insert_bywho=m513092005 ------>Jurnal_Rank=22.9 ------>authors4_c= ------>comm_author= ------>patent_EDate=None ------>authors5_c= ------>publish_day=1 ------>paper_class2Letter=None ------>page2=1782 ------>medlineContent= ------>unit=J0600 ------>insert_date=20091018 ------>iam=3 ------>update_date=None ------>author=??? ------>change_event=4 ------>ISSN= ------>authors_c= ------>score=368 ------>journal_name=Rapid Communications in Mass Spectrometry ------>paper_name=Determination of Urine Melamine by Validated Isotopic Ultra Performance Liquid Chromatography/ Tandem Mass Spectrometry. Rapid Communications in Mass Spectrometry ------>confirm_date=20091020 ------>tch_id=098038 ------>pmid=19437442 ------>page1=1776 ------>fullAbstract=Little is known about melamine (MEL) analysis in children~s urine. In this study, an isotopic ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method was developed and systematically validated for the analysis of MEL in urine. The method is easily performed and comprises acidification, solid-phase extraction (SPE) and UPLC/MS/MS analysis. (13)C(3)N(3)((15)NH(2))(3) was used as the internal standard (IS) for calibration. Transition ions m/z 127 > 85 of MEL and m/z 133 > 89 of the IS were used for quantification and m/z 127 > 68 of MEL was used for quantitative confirmation. Recovery and precision were assessed to guarantee the applicability of the method. The limit of quantification (LOQ) was 0.01 microg/mL while the calculated method detection limit was 0.006 microg/mL. The mean recoveries ranged from 96-99%. The method was then applied to analyze urine samples from children who had potentially consumed MEL-tainted dairy products during screening in Taiwan. Ten nephrolithiasis cases and 20 age- and gender-matched controls were selected for this study. Three out of the 10 nephrolithiasis cases had elevated levels of MEL. Comparatively, twenty age- and gender-matched non-nephrolithiasis controls consuming Taiwan brand milk powder all showed MEL levels lower than the detection limit except for two children with background levels of 0.02 microg/mL. The background level in these children urine samples was established by UPLC/MS/MS analysis. Positive results of urine MEL tests might be associated with nephrolithiasis in these candidates. Measurement of urine MEL concentration can be helpful in confirming MEL-related nephrolithiasis, but its clinical application needs further clarification. ------>tmu_sno=None ------>sno=22770 ------>authors2= ------>authors3=Tien-Jen Lin ------>authors4= ------>authors5= ------>authors6= ------>authors6_c= ------>authors=Wei-Chih Cheng ------>delete_flag=0 ------>SCI_JNo=None ------>authors2_c= ------>publish_area=0 ------>updateTitle=Determination of urine melamine by validated isotopic ultra-performance liquid chromatography/tandem mass spectrometry. ------>language=2 ------>check_flag=None ------>submit_date=None ------>country=None ------>no=12 ------>patent_SDate=None ------>update_bywho=None ------>publish_year=2009 ------>submit_flag=None ------>publish_month=6 |