A method for determining workers' exposure concentration to airborne nitrilotriacetic acid.

OBJECTIVES

This study aimed to establish a method to determine workers' exposure concentrations to airborne nitrilotriacetic acid (NTA).

METHODS

The sampler used an air sampling cassette containing a glass-fiber filter (GFF). After sampling, NTA extracted from the GFF using ultrapure water was derivatized using a boron trifluoride-methanol complex methanol solution and analyzed using a gas chromatograph-mass spectrometer. The developed method was validated for the following parameters: retention efficiency, storage stability, method quantitation limit, and reproducibility.

RESULTS

The retention efficiency for NTA on the GFF was 94%-101%, with the relative SD indicating the overall reproducibility (range 0.9%-2.4%). NTA on the GFF was stable at 4°C for at least 7 days. The method quantitation limit was 4.8 μg per sample.

CONCLUSIONS

The developed method will be useful for risk assessments because it can determine workers' exposure concentrations to NTA ranging from 0.02 to 4 mg/m3 in a 240 L sampling volume; the quantitation limit is 4.8 μg per sample.