| Summary: | 碩士 === 國立嘉義大學 === 應用化學系研究所 === 106 === In this study, a new ambient ionization by using screen-printed carbon plate (SPCP) as a spray plate, named as SPCP-spray has been developed. In comparison with the paper spray (PS), this method resulted in better reproducibility and signal intensity, whereas the time consumed in each analysis was cut down to half. When analyzing tea extracts, signal intensities of catechins obtained by SPCP-spray were ten times higher than those by PS. Signal intensities increased up to one hundred times for amino acids. In addition, the influence of SPCP surface polarity indicated that compounds with lower polarity adsorbed better toward less polar surface of carbon gel, leading to higher sensitivity when analyzing polar compounds. Furthermore, SPCP can be modified simply. The modified SPCP will expand the applicability of this method. SPCP-spray was successfully used to analyze tea extract and with high sensitivity and reproducibility. The detection limit for valine is 0.32 ng/L. To increase the sensitivity in the detection of less polar compounds, the surface of SPCP was preanodized. The surface of SPCP became less loar in the presence of carbonyl group generated during the preanodized process. The signal intensity of less polar standards was two times higher when the preanodized screen-printed carbon plate was used. When analyzing tea extracts by preanodized SPCP, the signal intensities of catechins increased one and a half times.
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