A high-throughput sample introduction system for chip-based microfluidic analysis was developed. The sampling system was composed of a capillary sampling probe attached to the microchip channel and an array of horizon...A high-throughput sample introduction system for chip-based microfluidic analysis was developed. The sampling system was composed of a capillary sampling probe attached to the microchip channel and an array of horizontally positioned micro-sample vials with slits fabricated on the bottom of each vial for pass-through of the sampling probe. The micro-sample vials array was fixed on a homebuilt platform capable of moving linearly under computer control. Sample introduction was performed by linearly moving the array of vials,allowing the probe inlet to sequentially enter the solutions in the vials through the slits. The use of a slotted vial array in the sample introduction system allowed convenient and rapid sample change with low sample volume in 10\+\{-9\} L range and high sampling frequency without requiring mechanical valves and pumps. The system was applied to achieve continuously automated sample change in a chip-based flow injection analysis system with absorption detection by using a liquid-core waveguide capillary flow-cell. High sampling throughput of 600 h -1 was obtained in this system with a sample consumption of only 4.3 nL for each cycle.展开更多
The analytical performance of two sample introduction systems, a low microwave powered thermospray nebulizer and a pneumatic nebulizer, coupled to an inductively coupled plasma atomic emission spectrometer, was compar...The analytical performance of two sample introduction systems, a low microwave powered thermospray nebulizer and a pneumatic nebulizer, coupled to an inductively coupled plasma atomic emission spectrometer, was compared. Several parameters including the sample uptake rate, the carrier gas flow rate and the observation height(above the load coil) were optimized and compared. Under the optimized conditions, the background equivalent concentration of Mn 257 610 nm, memory effect, HCl concentration effect on emission intensity of some selected elements, detection limits(DLs) and relative standard deviation(RSD) for Cd, Co, Cr, Mn, La with either nebulizer were studied. The DLs obtained with MWTN are lower than those with PN, but the RSDs are worse with MWTN than with PN.展开更多
文摘A high-throughput sample introduction system for chip-based microfluidic analysis was developed. The sampling system was composed of a capillary sampling probe attached to the microchip channel and an array of horizontally positioned micro-sample vials with slits fabricated on the bottom of each vial for pass-through of the sampling probe. The micro-sample vials array was fixed on a homebuilt platform capable of moving linearly under computer control. Sample introduction was performed by linearly moving the array of vials,allowing the probe inlet to sequentially enter the solutions in the vials through the slits. The use of a slotted vial array in the sample introduction system allowed convenient and rapid sample change with low sample volume in 10\+\{-9\} L range and high sampling frequency without requiring mechanical valves and pumps. The system was applied to achieve continuously automated sample change in a chip-based flow injection analysis system with absorption detection by using a liquid-core waveguide capillary flow-cell. High sampling throughput of 600 h -1 was obtained in this system with a sample consumption of only 4.3 nL for each cycle.
文摘The analytical performance of two sample introduction systems, a low microwave powered thermospray nebulizer and a pneumatic nebulizer, coupled to an inductively coupled plasma atomic emission spectrometer, was compared. Several parameters including the sample uptake rate, the carrier gas flow rate and the observation height(above the load coil) were optimized and compared. Under the optimized conditions, the background equivalent concentration of Mn 257 610 nm, memory effect, HCl concentration effect on emission intensity of some selected elements, detection limits(DLs) and relative standard deviation(RSD) for Cd, Co, Cr, Mn, La with either nebulizer were studied. The DLs obtained with MWTN are lower than those with PN, but the RSDs are worse with MWTN than with PN.
