Sampling cartridge cases

In the case of residue analysis in air, a known amount of air is passed through a sampling cartridge. The adsorbed alanycarb is extracted with acetonitrile. The acetonitrile in the extract is removed by rotary evaporation, the residue is dissolved in acetonitrile and the solution is subjected to HPLC analysis. 

Weigh and record the amount of powder in each cartridge case, blend carefully and spread on a clean cloth for examination. If no signs of deterioration are noted, take a sufficient sample for all the stability tests and destroy the rest... 

The interior of spent cartridge cases were sampled by dry swabbing with 0.25 g of acrilan fiber for FAAS analysis (dry swabbing) or by double-sided adhesive tape (Scotch pressure sensitive tape) on the end of a suitable diameter... 

In previous casework in which the majority of the FDR particles contained potassium and sulfur, frequently at high levels, it was thought that the ammunition responsible probably contained black powder. In most of the cases the type of ammunition was not known, whereas in others the sampling and analysis of the residue from the interior of the spent cartridge cases confirmed the presence of black powder. 

Oily crops such as soybeans and canola (oilseed rape) cannot be extracted with aqueous buffers, because the extraction solvent cannot permeate the hydrophobic plant tissue matrix. In these cases, homogenization in acetonitrile-hexane is recommended. This solvent mixture is able to extract sulfonylureas from these samples with a minimum of co-extracted oil. After extraction, the sulfonylureas partition into the acetonitrile phase while most of the oil stays in the hexane phase. Further cleanup is accomplished using a silica SPE cartridge and normal-phase conditions. 

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