scholarly journals Validation of a new screening, determinative, and confirmatory multi-residue method for nitroimidazoles and their hydroxy metabolites in turkey muscle tissue by liquid chromatography-tandem mass spectrometry

2012 ◽  
Vol 4 ◽  
pp. 130-138 ◽  
Author(s):  
Joe O. Boison ◽  
Philip A. Asea ◽  
Johanna L. Matus
2005 ◽  
Vol 51 (9) ◽  
pp. 1683-1690 ◽  
Author(s):  
Zoë Maunsell ◽  
Dennis J Wright ◽  
Sandra J Rainbow

Abstract Background: Measurement of 25-hydroxyvitamin D2 and D3 (25-OH D2 and D3) is essential for investigating vitamin D deficiency. Competitive binding techniques are unable to distinguish between the 2 metabolites and suffer from interference from other hydroxy metabolites of vitamin D. Methods: We used isotope-dilution liquid chromatography–tandem mass spectrometry (ID-LC-MS/MS) for routine determination of 25-OH D2 and D3 with a stable-isotope–labeled internal standard (IS). Serum samples (100 μL) were denatured with methanol–propanol containing IS, vortex-mixed, extracted into hexane, and dried under nitrogen. The reconstituted extract was chromatographed on a BDS C8 HPLC column, and the metabolites and IS were detected by electrospray ionization MS/MS in multiple-reaction monitoring mode. Results: 25-OH D2 and D3 and the IS nearly coeluted, whereas 1α-hydroxyvitamin D3 was separated; total run time was 8 min. The interassay CVs for 25-OH D2 were 9.5% and 8.4% at 52 and 76 nmol/L, respectively, and for 25-OH D3 were 5.1% and 5.6% at 55 and 87 nmol/L, respectively. The detection limit of the present method was <4 nmol/L for both metabolites. Method comparison with a commercial RIA measuring total 25-hydroxyvitamin D showed good correlation: y = 0.97x − 2.7 nmol/L (r = 0.91). The analytical system can assay 100 samples in 12.5 h. Conclusions: This simple robust interference-free LC-MS/MS assay is suitable for routine measurement of the 25-hydroxy metabolites of vitamins D2 and D3 in human serum. The assay has been in use for 9 months and has been used to assay more than 6000 routine samples.


2007 ◽  
Vol 21 (24) ◽  
pp. 4027-4032 ◽  
Author(s):  
Michael S. Filigenzi ◽  
Elizabeth R. Tor ◽  
Robert H. Poppenga ◽  
Linda A. Aston ◽  
Birgit Puschner

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