| Summary: | 碩士 === 國立臺灣師範大學 === 化學系 === 99 === A novel nano-controlled sample injection device for use in Hadamard transform/capillary electrophoresis (HT/CE) was successfully developed. Instead of commercial Tee products, an acrylic-Tee connector was well designed and made in-house. Three pieces of capillaries (used for sample solution and buffer solutions, respectively) can be tightly connected together with very low dead-volume. The sample solution was placed in a syringe injector (size, 10 µL) and was pushed out by a stepping motor which was controlled by a personal computer through a NI (National Instruments) PCI-6221 device. The volume of sample injection can be well controlled and calculated based on the steps (750- ~ 20,000-steps) of the stepping motor, corresponding to the injected volume of 1.3 nL ~ 49.4 nL. A riboflavin solution and a blue diode laser (wavelength, 473 nm; 100 mW) were selected as a model compound and the light source, respectively. Compared with a conventional single injection method, the S/N ratios were substantially improved after inverse Hadamard transformation of the encoded chromatogram. Under optimized conditions, when Hadamard matrices of 127 and 255 were used, the S/N ratios of the signals for riboflavin (concentration level, 0.03 ppm) were substantially improved to 5.3- and 7.9-fold, respectively, and those improvements are in good agreement with those obtained by theory (5.6- and 8.0-fold).
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