Inter-lab validation for the derivatization method by TFE/TFAA of acidic herbicides

A sensitive derivatization method by using the TFE/TFAA as derivative reagent is proposed for the determination of acidic herbicides in water, by using this method, method detection limits are improved by 10 times and sample volumes are decreased by 5 times compared with other methods such as U.S. EPA and SPEED 98. And also, in order to suggest higher creditable standard operating procedure (SOP), intra- and inter-lab validation test carried out by four laboratories include our lab. The results of intra and inter-lab validations in same experimental conditions show good linearity in given range of concentrations as a ng/ml, and range of accuracies and precisions show bias%, (for intra-lab validation) and bias%$, (for inter-lab validation), respectively.