An ultramicro method for analysis of lithium and other biologically important cations

A new method for Li+ analysis by flameless atomic absorption spectroscopy is several orders of magnitude more sensitive than previous methods. Li+ quantities as small as 1 - 10(-12) mol, or Li+ concentrattions as low as 1 - 10(-8) M, can determined with a coeffient of variation of 2--4%. The same technique can determine approx. 1 - 10(-14) mol of Ca2+ and Mg2+, and approx. 1 - 10(-13) mol of Na+ and K+.