English to French Tech/Engineering Chemistry; Chem Sci/Eng chemical analyses

To effectively eliminate all possible sources of hydrocarbon contamination from the analysis the following precautionary measures were taken prior to sample work-up:
All solvents were purchased as high purity grade.
Each batch was checked for purity by concentrating approximately 400 mL down to a small volume (< 1 mL) and analysing by GC;
All water used was distilled through an all glass still and dichloromethane extracted to minimise contamination from plasticisers;