Trace analysis of benzalkonium chloride on skin by flow injection ionspray mass spectrometry-mass spectrometry.

A method for the analysis of trace-level benzalkonium chloride has been established using flow injection ionspray mass spectrometry-mass spectrometry with multiple reaction monitoring. Quantification was carried out using an external standard based on peak area summation of each benzalkonium ion (C8, C10, C12, C14, C16 and C18) in the mass spectra. The multiple reaction monitoring technique provides additional specificity for identification and quantification. The quantification linear dynamic range was found to be 5.0-100.0 ng ml-1, the correlation coefficient > 0.999, and the detection limit 1.2 ng ml-1. The method was applied to quantify benzalkonium chloride on skin, which was sampled with a D-SQUAME tape from skin surface and extracted from the tape with methanol.