Microchip-based CEC of nitroaromatic and nitramine explosives using silica-based sol-gel stationary phases from methyl- and ethyl-trimethoxysilane precursors.
Microchip-based CEC of nitroaromatic and nitramine explosives with UV absorbance detection is described. The stationary phase was deposited in the microchip using the sol-gel process. Unique to this work, is the exclusive use of alkylated-trimethoxysilane precursors in the gel solution. Using alkylated precursors allows for the synthesis of a hydrophobic stationary phase in a single step. Three sol-gel formulations of increasing hydrophobicity and suitable for the separation of explosives are established from methyl- and ethyl-trimethoxysilane precursors. Increasing the alkyl-chain length improved the resolution significantly, allowing for the separation of up to seven analytes. Direct injection onto the head of the stationary phase for long injection times, results in sub-mg/L detection limits with little effect on separation efficiency.
Giordano
Braden C
BC
Naval Research Laboratory, Chemistry Division, Washington, DC 20375-5342, USA.
Terray
Alex
A
Collins
Greg E
GE
D000814:Aniline Compounds / Q000032:analysis*; D053801:Capillary Electrochromatography / Q000379:methods*; D046209:Electrophoresis, Microchip / Q000379:methods*; D053834:Explosive Agents / Q000032:analysis*; D005782:Gels; D006841:Hydrocarbons, Aromatic / Q000032:analysis*; D009578:Nitrobenzenes / Q000032:analysis*; D012680:Sensitivity and Specificity; D012821:Silanes / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D000814:Aniline Compounds; D053834:Explosive Agents; D005782:Gels; D006841:Hydrocarbons, Aromatic; D009578:Nitrobenzenes; D012821:Silanes; C071718:methyltrimethoxysilane; C015384:nitramine