Development of Microextraction by Packed Sorbent - Gas Chromatography-MassSpectrometry Method for Quantification of Nitro-Explosives in Aqueous andFluidic Biological Samples

A new method for quantification of twelve nitroaromatic compounds including 2,4,6-TNT, its metabolites and Tetryl with microextraction by packed sorbent (MEPS), followed by gas chromatography - mass spectrometric (GC-MS) detection in environmental and biological samples is developed. MEPS employ 4 mg of C18 silica sorbent inserted into a micro-volume syringe for sample preparation. Several parameters capable of influencing the microextraction procedure viz., number of extraction cycles, washing solvent, volume of washing solvent, elution solvent, elution solvent volume and pH of matrix etc., were optimized. Helium gas was used as mobile phase during GC operation. The developed method produced satisfactory results with excellent values of coefficient of determination (R2>0.9804) within the established calibration range. The extraction yields were satisfactory for all analytes (>89.32%) for aqueous samples and (>87.45%) for biological samples. The limits of detection values lie in the range 14 - 828 pg/mL. Due to procedural simplicity, high sensitivity and efficient resolution of all analytes, the developed method was applied successfully for quantification of nitro aromatic explosives in real aqueous and fluidic biological samples.