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Emerging Liquid Chromatographic Technologies for Environmental Monitoring
Oral Presentation
Prepared by M. Lee, S. Sharma, P. Farnsworth, H. Tolley
Department of Chemistry and Biochemistry and Department of Statistics - Brigham Young University, Brigham Young University, Provo, UT, 84602, United States
Contact Information: milton_lee@byu.edu; 801-422-2135
ABSTRACT
Liquid chromatography (LC) is increasingly used for the analysis of environmental pollutants. New developments in column technology (i.e., ultra-small particles, core-shell particles and monolithic columns), as well as improved sample concentration techniques and multidimensional arrangements, continue to improve separation power, speed of analysis and limits of detection that are essential for measuring current and emerging low-level target contaminants. However, taking LC instrumentation from a laboratory environment into the field for rapid on-site analysis opens a whole new set of challenges. LC has lagged behind gas chromatography (GC) in developments related to hand-portable instrumentation because of difficulties encountered in miniaturizing the high pressure pumping system and most common detectors (i.e., UV-absorption and mass spectrometry) to acceptable size, weight, robustness and power usage. Mobile phase transport and disposal in the field is an added concern associated with portable LC.
In an attempt to satisfy the requirements for field portable LC, a new battery-operated (24 V DC) LC system with nano-flow pumps, stop-flow injector and on-column UV-absorption detector (254 nm) is currently under development. This system provides greatly reduced consumption of solvents compared to conventional LC systems and superior performance compared to other miniaturized systems. Each pump weighs approximately 1.4 kg (3 lbs) and can generate up to 110 MPa (16,000 psi) pressure. A major advantage of the pumping system is that it does not employ a splitter, since it was specifically designed for capillary column use. Evaluation of a previous single-pump isocratic system yielded excellent results for flow rate calibration (>99.94% accuracy), percent injection carry-over (<0.31%) and retention time reproducibility (RSD values from 0.09 to 0.74%). The UV-absorption detector performance was found to be comparable to commercially available detectors. Systems such as this will allow unprecedented detection accuracy and speed at the source of contamination, which is essential for timely response necessary to protect human health and safety.
Oral Presentation
Prepared by M. Lee, S. Sharma, P. Farnsworth, H. Tolley
Department of Chemistry and Biochemistry and Department of Statistics - Brigham Young University, Brigham Young University, Provo, UT, 84602, United States
Contact Information: milton_lee@byu.edu; 801-422-2135
ABSTRACT
Liquid chromatography (LC) is increasingly used for the analysis of environmental pollutants. New developments in column technology (i.e., ultra-small particles, core-shell particles and monolithic columns), as well as improved sample concentration techniques and multidimensional arrangements, continue to improve separation power, speed of analysis and limits of detection that are essential for measuring current and emerging low-level target contaminants. However, taking LC instrumentation from a laboratory environment into the field for rapid on-site analysis opens a whole new set of challenges. LC has lagged behind gas chromatography (GC) in developments related to hand-portable instrumentation because of difficulties encountered in miniaturizing the high pressure pumping system and most common detectors (i.e., UV-absorption and mass spectrometry) to acceptable size, weight, robustness and power usage. Mobile phase transport and disposal in the field is an added concern associated with portable LC.
In an attempt to satisfy the requirements for field portable LC, a new battery-operated (24 V DC) LC system with nano-flow pumps, stop-flow injector and on-column UV-absorption detector (254 nm) is currently under development. This system provides greatly reduced consumption of solvents compared to conventional LC systems and superior performance compared to other miniaturized systems. Each pump weighs approximately 1.4 kg (3 lbs) and can generate up to 110 MPa (16,000 psi) pressure. A major advantage of the pumping system is that it does not employ a splitter, since it was specifically designed for capillary column use. Evaluation of a previous single-pump isocratic system yielded excellent results for flow rate calibration (>99.94% accuracy), percent injection carry-over (<0.31%) and retention time reproducibility (RSD values from 0.09 to 0.74%). The UV-absorption detector performance was found to be comparable to commercially available detectors. Systems such as this will allow unprecedented detection accuracy and speed at the source of contamination, which is essential for timely response necessary to protect human health and safety.