INDUSTRIAL APPLICATIONS OF CAPILLARY ZONE ELECTROPHORESIS MASS-SPECTROMETRY

Capillary zone electrophoresis was coupled on-line via a tricoaxial sh eath flow interface with a benchtop quadrupole mass spectrometer (CZE- MS) equipped with a (pneumatically assisted) electrospray ionization s ource. Experimental parameters were optimized for operation in the neg ative-ion scan mode. The system was applied to the fingerprinting of a n alkylsulphate detergent, to the identification of an impurity in a c hloramine-T disinfectant, to the characterization of a complex polyeth oxylated alkylphosphate emulgator, to the analysis of phenoxy acid her bicides and to the impurity profiling of MCPP. The optimized system wa s found to fully maintain the CZE separation performance, showing up t o I million theoretical plates for the low-molecular-mass analytes stu died. The sensitivity in the full-scan mode was typically in the picog ram range and sufficient for the separation and identification of mino r impurities in these industrial chemicals, down to the 0.1% level. In addition, the feasibility of on-column transient isotachophoresis (IT P-CZE-MS) under high electroosmotic flow conditions has been demonstra ted for sample preconcentration and subsequent identification of trace impurities.