title: A rapid method for estimating nitrate in biological samples using gas chromatography with a flame-ionization detector or a thermal energy analyzer.
abstract: A simple, rapid method for estimating the nitrate content of biological samples was developed and tested. The method was based on the nitration of benzene under acidic conditions. The resulting nitrobenzene was analysed by gas chromatography with either a flame ionization detector (FID) or a Thermal Energy Analyzer (TEA) for detection. Recovery of nitrate added to urine, blood, saliva or faeces was 96, 97, 96 and 98%, respectively. Coefficients of variation for repeated analyses ranged from 2.2% for saliva to 12% for blood. Sensitivity was of the order of 0.5-1.5 mg/kg for the FID and 0.02-0.05 mg/kg for the TEA.
mesh_terms: D002849:Chromatography, Gas / Q000295:instrumentation; D005243:Feces / Q000032:analysis; D005410:Flame Ionization; D006801:Humans; D009566:Nitrates / Q000032:analysis* / Q000097:blood / Q000652:urine; D012463:Saliva / Q000032:analysis; D013696:Temperature
chemical_list: D009566:Nitrates