Analysis of perchlorate in dried blood spots using ion chromatography and tandem mass spectrometry.

Because of health concerns surrounding in utero and neonatal exposure to perchlorate, we developed a method for analyzing perchlorate in the dried blood spots (DBS) of newborns. Ion chromatography was interfaced with electrospray ionization tandem mass spectrometry to measure blood perchlorate levels in DBS samples as low as 0.10 ng/mL. Measurement of perchlorate in DBS indicated good precision (relative standard deviations ranging from 5.8% to 16.2%) and accuracy (% difference values ranging from -11.3% to -12.1%). Perchlorate was detectable in 100% of the DBS collected from 100 newborns. These samples had a median blank-adjusted concentration of 1.88 ng/mL. Such data support the utility of this method to quantify perchlorate levels in DBS samples. Applying this method to analyze neonatal DBS will improve perchlorate exposure assessments of this susceptible population.