Supplement to: Granger, Julie; Boshers, Danielle S; Böhlke, John Karl; Yu, Dan; Chen, Nengwang; Tobias, Craig R (2020): The influence of sample matrix on the accuracy of nitrite N and O isotope ratio analyses with the azide method. Rapid Communications in Mass Spectrometry, 34(1), https://doi.org/10.1002/rcm.8569