DETERMINATION OF TOTAL N-NITROSO COMPOUNDS IN BIOLOGICAL-FLUIDS BY PHOTOLYTIC DENITROSATION AND THERMAL-ENERGY ANALYSIS

Quantification of total N-nitroso compounds (NOC) in urine and gastric juice is achieved by combining photolytic denitrosation with thermal energy analysis. The minimum mass detection limit of the technique is about 10 pmole NO. Urine samples with NOC concentration as low as 200 nmolL-1 can be analyzed with a precision of approximately 5-10%. The m inimum concentration detection limit for gastric juice samples is abou t 1 mumolL-1. Except for nitrite, no interference is observed from nit rogenous compounds present in urine and gastric juice. The nitrite int erference is effectively eliminated with sulphamic acid.