Validation of chlordecone analysis for native and remediated French West Indies soils with high organic matter content
Abstract
An analytic method was developed and validated for the analysis of chlordecone in the three main types of FrenchWest Indies soils: Ferralsol, Andosol and Nitisol with and without the addition of Daramend® and compost amendment used in a remediation process. The method consists in analysis by gas chromatography coupled with triple quadrupole mass spectrometry after pressurised liquid extraction. The high natural content of organic matter in the soils coupled with the additional exogenous organic matter from the amendments tested lead to a complex extract. Transnonachlor was used as surrogate to correct the results for extraction efficiency, and 13C chlordecone was added as internal standard to mimic as closely as possible the behaviour of chlordecone and suppress possible side effects during its analysis. The key parameters of the method (linearity, repeatability, interday precision, specificity, extraction efficiency and limit of quantification) were validated in accordance with the NF T 90-210 standard method. The limit of quantification is 0.03 mg/kg. Uncertainty (k=2) was 40 % for concentrations lower than or equal to 1 mg/kg, and 30 % for concentrations greater than 1 mg/kg.