Validation of geosmin and 2-methyl-i-borneol analysis by CLSA-GC-FID method to obtain ISO-17025 accreditation

Abstract

A study of the accreditation process using closed loop stripping analysis (CLSA)-gas chromatography (GC)-flame ionization detection (FID) methodology for the analysis of geosmin and 2-methyl-i-borneol (MIB) is performed, completing the instrumental validation process. Quality parameters, such as the linearity ranges, repeatability and reproducibility, efficiencies, matrix effects, and interference, are presented. The experimental work is completed with a study of the associated uncertainty using a "Bottom-up Approach Method" and a short description of a control-protocol for preserving the validation conditions as a method of quality assurance protocol. The results show that CLSA-GC-FID-MS is a very good tool for the analysis of geosmin and MIB at a low level threshold, and the working range obtained is 10-400 ppt (ng/L) for geosmin and 15-400 ppt for MIB, respectively, in both drinking and natural waters. Uncertainty was approximately 16% for both compounds; good reproducibility with precision below 10% and bias between 85-90% for the three matrices considered are obtained.