Application Of Isotope Dilution Mass Spectrometry In The Development Of Serum Uric Acid Reference Material And Determination Of Urea In Milk Powder

With the development of society, the level and the requirement in analytical chemistry field become more and more important. The method of isotope dilution mass Spectrometry has been applied widely in clinical chemistry, food safety, standard reference material, environment and international comparison because of its advanced characteristic.The standard reference material of uric acid in frozen serum was determined by high performance liquid chromatography isotope dilution mass Spectrometry (HPLC/IDMS). According to criterion of the national first class standard reference material research technology, the uniformity, stability and uncertainty were studied respectively. The results showed that the uniformity of the reference material of uric acid in frozen serum was satisfactory. The one-year stability inspection of the reference material of uric acid in frozen serum was suitable for the technical requirement of the national first class standard reference material. This standard reference material can also provide a technical support and value traceability assurance for the measurement and research of clinical test, medicine, dietetics and sanitation quarantine. The urea in milk powder was determined by gas chromatography isotope dilution mass Spectrometry (GC/IDMS) using the [¹³C, ¹⁵N₂]urea labeled material as the internal standard material. The conditions of pretreatment, derivation temperature and time, gas chromatography and mass Spectrometry were studied. The results was satifactory with a linear range of 10mg/kg～1600mg/kg and recoveries from 97.30% to 99.17%, respectively. The established method provided a strong technique support for the food safety and quality control.