1. ® February 2013 Page 1 of 1 RR-108-B-0.00 ChemDAQ Inc. • 300 Business Center Drive • Pittsburgh, PA • 15205 phone 412.787.0202 • fax 412.788.2526 Validation of Peracetic Acid Test Gas Titrations Background: ChemDAQ Inc manufactures and sells a gas monitor for peracetic acid (PAA) for occupational safety. To calibrate this gas monitor ChemDAQ generates peracetic acid test gas. The gas flow is typically 1 lpm, controlled by a mass flow controller but can be varied as needed. Validation Method: The PAA test gas concentration is analyzed by titration approximately weekly. There are no standard methods for the analysis of PAA vapor, and so this analysis was validated by the method of Effkemann et al 1 , based on the oxidation of ABTS (2,2’-azino-bis(3- ethylbenzothiazoline)-6-sulfonate) by PAA with formation of a radical cation which is characterized by four strong absorption maxima between 405 nm and 810 nm. ChemDAQ has established an accuracy specification for the PAA test gas of 5% total error. Validation Results: The repeatability test comprised 15 separate runs comparing PAA concentration by the titration compared to Effkemann. The mean of the validation data was 0.531ppm and the standard deviation was 0.0116ppm, compared with the titration value of 0.53PPM give the following results: Gas Error Specification: <5% Accuracy measured: 0.15% Precision measured: 2.2 % Total Gas Concentration Error: <2.4% These results indicate that the titration is validated within acceptable limits. 1 S. Effkemann, S. Brødsgaard, P Mortensen, S.A. Linde, Karst; “Spectrophotometric and direct- reading methods for the analysis of gas phase peroxyacetic acid;” Fresenius J Anal Chem (2000) 366 :361–364