Quantitation Limit Validation Methods and Implications for Chemical Permeation Testing of Personal Protective Equipment

摘要

Chemical permeation test methods are intended to ensure personal protective equipment (PPE) will protect users against hazardous chemical risk. ASTM F739-12e1, Standard Test Method for Permeation of Liquids and Gases through Protective Clothing Materials under Conditions of Continuous Contact, establishes the test procedure to determine the resistance of PPE to chemical permeation but does not detail analytical methods or quantitation limit validation. There is no industry-wide consensus on the determination of detection limits (LoD) or quantitation limits (LoQ) despite their importance in setting reporting limits and obtaining reliable data. Strictly defining analytical techniques in the standard has the potential to dismiss the use of suitable instrumentation but defining an LoQ validation procedure will exclude unreliable methods while allowing flexibility in the choice of analysis. In this study, data from two common detectors, mass spectrometry and flame ionization, are compared by their performance in measurement of carbon disulfide. Although detection characteristics of a flame ionization detector (FID) should preclude its use for quantitative analysis of carbon disulfide, it is used in the study to highlight variability in results that can be seen despite the application of current quality control parameters within the standard. The differences in values obtained demonstrate how additions to ASTM F739 are needed to ensure that testing laboratories are held to a more rigorous validation requirement. Although most laboratories have quality procedures in place, adherence to a chosen level of confidence would increase the assurance provided by chemical permeation testing.