This project contents two sections: In first section, for the first time, simultaneous analysis of caffeine and theophylline was done by ion mobility spectrometry (IMS) only, without a powerful separation technique (e.g. HPLC). Ion mobility spectrometry with low cost, inexpensive maintenance and very fast analysis makes an attractive technique for the simultaneous determination of the caffeine and theophylline in foodstuff samples and biological matrices. In this study, the extraction protocol using molecular imprinted polymer-solid phase extraction (MIP-SPE) was successfully used to directly extract caffeine and theophylline from real samples. The results obtained provided the detection limits of 0.2 and 0.3 µg/mL for caffeine and theophylline, respectively. The linear dynamic range of about 2 orders of magnitude was obtained for these compounds. Also, the proposed method was used to analyze various real samples of green tea and spiked human plasma, and the obtained results confirmed the capability of ESI-IMS for simultaneous detection of caffeine and theophylline. In second section, a new application of negative ESI-IMS has been introduced for determination of thiocyanate present in various environmental, industrial and biological real samples. The methodology reported here is very simple and rapid in addition to inexpensive for direct analysis of SCN - in human saliva without any separation and extraction methods, helping us to distinguish smokers from non-smokers. Analyze time required for this method was about 15 minutes. The limit of detection 0.003 µg/mL and the linear dynamic range 0.01- 1.00µg/mL was obtained. Also, the proposed method was used to analyze various real samples of human saliva, and the obtained results confirmed the capability of ESI-IMS for direct determination of salivary thiocyanate.
