Determination of nortriptyline in aqueous sample by dispersive liquid phase microextraction followed by ion mobility spectrometry

Nortriptyline is a tricyclic antidepressant which is frequently used for treating clinical depression. Determination of nortriptyline in the different real samples can be very important, particularly in pharmacokinetic and environmental studies [1,2]. Therefore a fast and sensitive analytical method can be very helpful. Ion mobility spectrometry (IMS) has almost all features for this purpose [3]. On the other hand, a fast and efficient microextraction method can obtain the lower detection limit and better clean-up for real sample analysis. Consequently, in this study, a dispersive liquid phase microextraction (assisted by a homogenizer) combined with ion mobility spectrometry has been applied for determination of nortriptyline. Figure 1 reveals the ion mobility spectrum of nortriptyline. Effective factors such as solvent type, salt addition, stirring rate and extraction time have been investigated and optimized. Analytical features of the method were evaluated under optimized conditions. Limit of detection was achieved 7 μg/L and relative standard deviations were less than 11%. The calibration curve was obtained in the range of 20–500 μg/L with a good linearity (R2 > 0.9946). Human urine, plasma and river water samples were studied as real samples for the evaluation of the method and average relative recoveries were found 87%, 74% and 103% respectively.