基质稀释同位素质谱法测定微量富氘生物样品δD值

Research on measuring the 8D of the bio-samples enriched with deuterium by matrix dilution isotope ratio mass spectrometry

目的建立一种分析检测方法——基质稀释同位素质谱法，并测定微量富氘生物样品的6I）值。方法通过优化实验条件，如基质的选取、氧化燃烧的温度及时间、样品和氧化剂吸附水的脱除及氧化剂的用量等，建立基质稀释同位素质谱法，并用该法测定基质牛血清白蛋白（BSA）及两组微量富氘生物样品（A和B）的δDVSMOW值。结果本研究成功地构建了基质稀释同位素质谱法，最终选取BSA为基质，用量为5mg；氧化剂用量为CuO（500nag），V2O5（50mg）；100℃条件下脱吸附水20min；燃烧氧化温度为850℃，反应时间为30min。基质稀释同位素质谱法成功地测定了基质BSA及用A、B两种富氘生物样品制备的系列样本的δDVSMOW值。δDVSMOW值变化随生物样品A和B的加入量呈现良好的线性关系（R2〉0．99），两条直线的截距分别为-75和-74，与基质BSA的测定结果相吻合。结论基质稀释同位素质谱法能够用于测定微量富氘生物样品的δDVSMOW值。

Objective To measure the δD value of the bio-materials which are microgram and enriched deuterium by matrix dilution-isotope ratio mass spectrometry. Methods Matrix dilution-isotope ratio mass spectrometry was proposed and established by optimizing experimental condition, such as the selection of the matrix, the combusting temperature and reaction time. The time of removing adsorbed water from samples and the oxidants and the amounts of the oxidants were also studied. Then the δDVSMOW value of bovine serum albumin （BSA） as matrix was measured by matrix dilution-isotope ratio mass spectrometry, and also for the two kinds of bio-materials （A and B） which were microgram and enriched deuterium. Results Matrix dilution-isotope ratio mass spectrometry was proposed and established successfully in this research. BSA was matrix, and the amount of BSA was 5mg. The combustion temperature and time of the sample was 850℃ and 30min, respectively. The amount of oxidants were CUO（500 nag） and V205 （50 mg）. The time of removing ad- sorbed water from the samples and the oxidants was 20 min at 100℃ before the combustion of samples. The δDVSMOW value of the BSA and the series of samples prepared by enriched deuterium A and B were measured successfully by matrix dilution-isotope ratio mass spectrometry. The relatiouship of δDVSMOW value and the amount of deuterated A or B showed fine linearity （ R2 〉 0.99）. The intercept of curves were - 74 and - 75 respectively, which were in accordance with the δDVSMOW value of BSA as matrix. Conclusions The matrix dilution-isotope ratio mass spectrometry can be used to measure the δDVSMOW value of the bio-materials, which are microgram and enriched deuterium.