Rapid screening of clenbuterol in urine samples by desorption electrospray ionization tandem mass spectrometry

2008 ◽  
Vol 22 (12) ◽  
pp. 1882-1888 ◽  
Author(s):  
Ziqing Lin ◽  
Sichun Zhang ◽  
Mengxia Zhao ◽  
Chengdui Yang ◽  
Depu Chen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Electrospray Ionization ◽  
Desorption Electrospray Ionization ◽  
Urine Samples ◽  
Rapid Screening ◽  
Tandem Mass ◽  
Ionization Tandem Mass Spectrometry

scholarly journals Comprehensive Detection of Disorders of Purine and Pyrimidine Metabolism by HPLC with Electrospray Ionization Tandem Mass Spectrometry

2006 ◽  
Vol 52 (6) ◽  
pp. 1127-1137 ◽  
Author(s):  
Susen Hartmann ◽  
Jürgen G Okun ◽  
Christiane Schmidt ◽  
Claus-Dieter Langhans ◽  
Sven F Garbade ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Electrospray Ionization ◽  
Multiple Reaction Monitoring ◽  
Dihydropyrimidine Dehydrogenase ◽  
Urine Samples ◽  
Tandem Mass ◽  
Pyrimidine Metabolism ◽  
Phosphoribosyl Transferase ◽  
Ionization Tandem Mass Spectrometry

Abstract Background: Clinical presentation and disease severity in disorders of purine and pyrimidine metabolism vary considerably. We present a method that allows comprehensive, sensitive, and specific diagnosis of the entire spectrum of abnormalities in purine and pyrimidine metabolism in 1 analytical run. Methods: We used reversed-phase HPLC electrospray ionization tandem mass spectrometry to investigate 24 metabolites of purine and pyrimidine metabolism in urine samples from healthy persons and from patients with confirmed diagnoses of inherited metabolic disorders. Urine samples were filtered and diluted to a creatinine concentration of 0.5 mmol/L. Stable-isotope–labeled internal standards were used for quantification. The metabolites were analyzed by multiple-reaction monitoring in positive and negative ionization modes. Results: Total time of analysis was 20 min. Recovery (n = 8) of a compound after addition of a known concentration was 85%–133%. The mean intraday variation (n = 10) was 12%. The interday variation (n = 7) was ≤17%. Age-related reference intervals were established for each compound. Analysis of patient urine samples revealed major differences in tandem mass spectrometry profiles compared with those of control samples. Twelve deficiencies were reliably detected: hypoxanthine guanine phosphoribosyl transferase, xanthine dehydrogenase, purine nucleoside phosphorylase, adenylosuccinate lyase, uridine monophosphate synthase, adenosine deaminase, adenine phosphoribosyl transferase, molybdenum cofactor, thymidine phosphorylase, dihydropyrimidine dehydrogenase, dihydropyrimidinase, and β-ureidopropionase. Conclusion: This method enables reliable detection of 13 defects in purine and pyrimidine metabolism in a single analytical run.

scholarly journals Defects in Pyrimidine Degradation Identified by HPLC-Electrospray Tandem Mass Spectrometry of Urine Specimens or Urine-soaked Filter Paper Strips

2000 ◽  
Vol 46 (12) ◽  
pp. 1916-1922 ◽  
Author(s):  
Henk van Lenthe ◽  
André B P van Kuilenburg ◽  
Tetsuya Ito ◽  
Albert H Bootsma ◽  
Arno van Cruchten ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Electrospray Ionization ◽  
Filter Paper ◽  
Degradation Products ◽  
Degradation Pathway ◽  
Urine Samples ◽  
Tandem Mass ◽  
Pyrimidine Degradation ◽  
Ionization Tandem Mass Spectrometry

Abstract Background: Urinary concentrations of thymine, uracil, and their degradation products are useful indicators of deficiencies of enzymes of the pyrimidine degradation pathway. We describe a rapid, specific method to measure these concentrations to detect inborn errors of pyrimidine metabolism. Methods: We used urine or urine-soaked filter-paper strips as samples and measured thymine, uracil, and their degradation products dihydrothymine, dihydrouracil, N-carbamyl-β-aminoisobutyric acid, and N-carbamyl-β-alanine. Reversed-phase HPLC was combined with electrospray ionization tandem mass spectrometry, and detection was performed by multiple-reaction monitoring. Stable-isotope-labeled reference compounds were used as internal standards. Results: All pyrimidine degradation products could be measured in one analytical run of 15 min. Detection limits were 0.4–4 μmol/L. The intraassay imprecision (CV) of urine samples with added compounds was 1.3–12% for liquid urines and 1.0–10% for filter-paper extracts of the urines. The interassay imprecision (CV) was 3–11% (100–200 μmol/L). Recoveries were 89–99% at 100–200 μmol/L and 95–106% at 1 mmol/L in liquid urines, and 93–103% at 100–200 μmol/L and 100–106% at 1 mmol/L in filter-paper samples. Correct identifications of deficiencies of the pyrimidine-degrading enzymes were readily made with urine samples from patients with known defects. Conclusions: HPLC with electrospray ionization tandem mass spectrometry allows rapid testing for disorders of the pyrimidine degradation pathway, and filter-paper samples allow easy collection, transport, and storage of urine samples.

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