“…Ang II in biological samples has been commonly measured by immunoassays, which are notoriously susceptible to interference (Lawrence et al, 1990; Nussberger et al, 1985; Templ & Templ, 1991; Voelker et al, 1994; Volland et al, 1999; Yasunaga et al, 1992). Direct measurement of Ang II by LCMS methods can overcome the specificity problem and was originally reported in 2007 (Ali et al, 2014; Bernstone et al, 2021; Boccardo et al, 2015; Cui et al, 2007; Hildebrand et al, 2013; Lee et al, 2013; Nicola et al, 1995; Schulz et al, 2014; Shen et al, 2019; van Rooyen et al, 2016).…”