A proper and systematic qualitative method validation procedure and its application to gas chromatography-mass spectrometry analysis of Chemical Weapons Convention related chemicals

•A proper and systematic qualitative method validation procedure was proposed.•The application was shown on the analysis of CWC-related compounds.•The use of accordance and concordance is not very common in forensic applications.•The novel aspects of validation may be of wider interest to the forensic community. [Display omitted] Performing a detailed qualitative validation, which is carried out by many laboratories in the forensic community, has been the main goal of this study. In this study, a proper and systematic qualitative method validation procedure was proposed, and its application was shown on the analysis of Chemical Weapon Convention (CWC) related compounds in organic samples. All validation steps were described in detail. The study was carried out in pump oil and dichloromethane (DCM). The limit of detection values were determined for each compound and were found in the range of 0.5–2.0 µg mL−1 in pump oil and 0.08–1.5 µg mL−1 in DCM. The validation parameters were calculated, such as the rates of sensitivity, selectivity, false-negative, false-positive, also accordance and concordance. The predicted and obtained results were compared by using Cohen's Kappa Coefficient Test, and the compatibility of the results was found as "very good". After the validation procedure, all of the validation results were evaluated, and the proposed method was confirmed as appropriate for the analysis of CWC-related compounds in organic samples. The applicability of the validated method was proved by determining the CWC-related compounds in organic samples provided by the Organization for the Prohibition of Chemical Weapons during proficiency tests.