| Summary: | 碩士 === 高雄醫學大學 === 公共衛生學系公共衛生學碩士班 === 105 === Ambient mass spectrometry using an interchangeable thermal desorption/electrospray ionization source (TD–ESI) is a relatively new technique that has had only a limited number of applications to date. Nevertheless, this direct-analysis technique has potential for wider use in analytical chemistry (e.g., in the rapid direct detection of contaminants, residues, and adulterants on and in food) when operated in dual-working mode (pretreatment-free qualitative screening and conventional quantitative confirmation) after switching to a TD–ESI source from a conventional ESI source. Herein, we describe the benefits and challenges associated with the use of a TD–ESI source to detect adulterants on traditional Chinese pastries (TCPs), as a proof-of-concept for the detection of illegal colorants. While TD–ESI can offer direct (i.e., without any sample preparation) qualitative screening analyses for colorants on TCPs with adequate reproducibilities (RSDs<10.0%)、detection capabilities (<0.2 ng/sample area) and detection threshold range (0.08-0.13 ng/sampling area) within 30 s; the use of TD–ESI for semi-quantification analyses is applicable for colorants in methanolic solutions with good linear range (0.5-10 mg L-1)、linearities (R2≧0.992) and detection limits (0.5 ppb) and for homogeneous solid matrices (e.g., tang yuan). Briefly, it is anticipated that in the future this type of technique could be employed in qualitative screening applications on solid samples for food safety control.
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