Elimination of boron memory effect in inductively coupled plasma-mass spectrometry by ammonia gas injection into the spray chamber during analysis

Injection of 10–20 ml/min of ammonia gas into an inductively coupled plasma-mass spectrometry (ICP-MS) spray chamber during boron determination eliminates the memory effect of a 1 μg/ml B solution within a 2-min washing time. Ammonia gas injection also reduces the boron blank by a factor of four and enhances the sensitivity by 33–90%. Boron detection limits are improved from 12 and 14 to 3 and 4 ng/ml, respectively, for two ICP-MS instruments. Trace boron concentrations in certified reference materials agree well using ammonia gas injection.