Due to the proteomics revolution, multi-dimensional separation and detection instruments are required to evaluate biomolecule and complex natural samples. many HPLC detectors require analytes to have specific chemical properties (i.e., UV detectors require analytes to be chromophores) and do not offer additional component information besides HPLC retention times. Unlike many HPLC detection methods, IMS does not require specific analyte properties and provides a second dimension of information (ion mobilities). The coupling of HPLC with ESI-IMS would provide a selective and sensitive detector without the expensive and extensive requirements of MS. In this study, electrospray ionization (ESI) ion mobility spectrometry (IMS) was evaluated as an additional separation after HPLC separations. Due to differences in the two mobile phase flow rate, HPLC and ESI-IMS, a splitter was built to divide the flow rate of HPLC column with the ratio of (1/100). Furthermore, Coupling of HPLC to ESI-IMS was carried out by using a modified HPLC tube and directly was used as the needle of electrospray for the first time. Effect of electric field around the grid was investigated to enhance resolution of the ESI-IMS. Imaging system was designed for the first time for ESI-IMS. This system allows us to monitor any changes in electrospray. We could find conditions for producing a stable electrospray. A mixture of five pesticides were determined using (LC/ESI/IMS) to describe the response and analytical performance of an ion mobility spectrometer as a detector for liquid chromatography. Coelution of two peaks due to non-optimal HPLC conditions occurred and these two peaks could not be distinguished by HPLC with UV detection. In contrast, the single ion mobility spectrum provided separation of each pesticide as well as providing a second degree of analyte identification (HPLC retention time and IMS mobility). Detection limit for Carbaryl, Amitraz, Captafol, Folpet and Phosmet were about 0.03, 0.2, 4.4, 18.5 and 0.3 respectively. In spite of splitting detection limit for Carbaryl and Phosmet by ESI-IMS were lower than UV-Vis detector. In the second part of this project, the potential of HPLC-ESI-IMS for simultaneous determination of Antihistamines were investigated. Detection limit for Promethazin, Clemastin, Cyproheptadine, Ketotifen, Cinnarizine and diphenhydramine were about 2.6, 0.7, 0.9, 1.3, 0.9 and 0.8 respectively. Diphenhydramine and Promethazine that have similar drift time and ESI-IMS cahy;not separate them, analyze by HPLC-ESI-IMS by two dimension separation. The detection limits for some compounds were lower in HPLC-ESI-IMS than that in HPLC-UV-Vis in spite of splitting. However, the detection limits for other compounds could be reduced using a capillary colum instead of a traditional column.
