A new rapid method for quantification of nitrogen in human serum employing the 14N(p,p' gamma)14N reaction: application to human pregnancy.
The total nitrogen concentrations in dried serum from 54 pregnant women and 17 newborn babies were determined by a new application of the 14N(p,p' gamma)14N reaction resonance at 3.9 MeV. The samples were bombarded in a He atmosphere by 4.1 MeV protons from a tandem Van de Graaff accelerator. The mean dry-weight nitrogen concentration in serum sampled during early pregnancy (6-12 weeks; 13.9 g per 100 g +/- 5.4%) was significantly higher than that in serum sampled during late pregnancy (38-42 weeks: 13.0 g per 100 g +/- 3.9%, p less than 0.001) and than that in serum taken from the umbilical cord (13.3 g per 100 g +/- 4.6%, p less than 0.01). The nitrogen levels measured using this rapid nuclear technique, applied for the first time to human serum analysis, agree well with parallel Kjeldahl analyses.
D005260:Female; D005312:Fetal Blood / Q000032:analysis; D006801:Humans; D007231:Infant, Newborn; D009584:Nitrogen / Q000097:blood*; D009590:Nitrogen Radioisotopes; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011263:Pregnancy Trimester, Third; D011865:Radioisotope Dilution Technique / Q000295:instrumentation
D009590:Nitrogen Radioisotopes; D009584:Nitrogen