Castegnaro M, Massey R C, Walters C L
Food Addit Contam. 1987 Jan-Mar;4(1):37-43. doi: 10.1080/02652038709373612.
Two collaborative studies have been made of the method devized for the determination of N-nitroso compounds as a group, which involves their selective denitrosation with hydrogen bromide in glacial acetic acid, followed by the measurement of the nitric oxide liberated using a chemiluminescence analyzer, such as the TEA. Considerable variation was evident between the results in the first study, most of the values reported being low. This situation undoubtedly arose from the carry-over of traces of hydrogen bromide from one determination to the next, which resulted in premature denitrosation. The precision and consistency of the results were greatly improved in the second study, for which additional precautions had been recommended. All of the six participating laboratories reported reasonably consistent values, the coefficients of variation being 27.9% and 21.1% respectively, at the levels of spiking of N-nitrososarcosine equivalent to 32.9 ng and 146.4 ng of nitric oxide.
针对用于测定N-亚硝基化合物总量的方法开展了两项合作研究，该方法包括在冰醋酸中用溴化氢对其进行选择性脱亚硝化，然后使用化学发光分析仪（如TEA）测量释放出的一氧化氮。在第一项研究中，结果之间存在明显差异，报告的大多数值都偏低。这种情况无疑是由于痕量溴化氢从一次测定带入下一次测定，导致过早脱亚硝化。在第二项研究中，由于采取了额外的预防措施，结果的精密度和一致性有了很大提高。所有六个参与实验室报告的值都相当一致，在相当于32.9纳克和146.4纳克一氧化氮的N-亚硝基肌氨酸加标水平下，变异系数分别为27.9%和21.1%。
