1987 Volume 3 Issue 6 Pages 561-564
A simple, sensitive and accurate method for the determination of sodium mercaptoundecahydrododecaborate, Na210B12H11SH, which is one of the most useful agents for boron neutron-capture therapy of brain tumors, was developed by spectrophotometry with 5, 5′-dithiobis(2-nitrobenzoic acid) [DTNB]. The color development based on 2-nitro-5-mercaptobenzoic acid liberated from DTNB by an exchange reaction of the sulfhydryl group showed maximal absorbance at 398nm with 1.65×104dm3 mol-1 cm-1. Beer′s law was obeyed up to 6×10-4mol dm-3. The detection limit was 2×10-5mol dm-3.