Skip to main content
Skip to main menu Skip to spotlight region Skip to secondary region Skip to UGA region Skip to Tertiary region Skip to Quaternary region Skip to unit footer


Ambient Ionization Mass Spectrometry Application in Therapeutic Drug Monitoring

Head shot of Ngan H Thai, Asian woman with long dark hair, wearing a black jacket and lace blouse
Ngan H Thai
Graduate Student, Department of Chemistry
University of Georgia
iSTEM-2 Building, Room 1218
Analytical Seminar

Therapeutic drug monitoring (TDM) is a quantitative test that measures drug dosage to prevent underdose or overdose in clinical practice [1]. Ultrahigh sensitivity and selectivity techniques such as mass spectrometry has superior advantages over traditional immunoassay technique in the diagnosis and quantification of therapeutic drug [2]. While liquid chromatography coupled with mass spectrometry has shown to be a "golden standard" for TDM [1,2], it requires complex sample preparation and chromatographic separation that may affect clinical demand time [2,9]. Therefore, the development of quick and simple direct sampling mass spectrometry method is essential [3]. Ambient ionization was introduced into the literature in the early 2000s as a method that allows ionization of unmodified or minimally modified sample [4]. More recently, researchers have been working on developing ambient ionization mass spectrometry (AIMS) method with little to no sample preparation that provides rapid results in a short time. In preliminary studies, AIMS has shown to effectively detect and quantify low concentration samples [5-10]. Studies have also shown how AIMS combined with ion mobility provides rapid diagnosis of complex or isomeric compounds without chromatographic separation [6,8,10]. The utilization of direct sampling technique such as desorption electrospray ionization (DESI), direct analysis in real time (DART), and paper spray (PS) coupled with mass spectrometry have advantageous for drug monitoring.


[1] Adaway, J. E.; Keevil, B. G. Therapeutic Drug Monitoring and LC–MS/MS. Journal of Chromatography B 2012, 883-884, 33–49.

[2] Banerjee, S. Empowering Clinical Diagnostics with Mass Spectrometry. ACS Omega 2020, 5 (5), 2041–2048.

[3] Pu, F.; Chiang, S.; Zhang, W.; Ouyang, Z. Direct Sampling Mass Spectrometry for Clinical Analysis. The Analyst 2019, 144 (4), 1034–1051.

[4] Feider, C. L.; Krieger, A.; DeHoog, R. J.; Eberlin, L. S. Ambient Ionization Mass Spectrometry: Recent Developments and Applications. Analytical Chemistry 2019, 91 (7), 4266–4290.

[5] Morato, N. M.; Cooks, R. G. Inter-Platform Assessment of Performance of High-Throughput Desorption Electrospray Ionization Mass Spectrometry. Talanta Open 2021, 4, 100046.

[6] Roscioli, K. M.; Tufariello, J. A.; Zhang, X.; Li, S. X.; Goetz, G. H.; Cheng, G.; Siems, W. F.; Hill, H. H. Desorption Electrospray Ionization (DESI) with Atmospheric Pressure Ion Mobility Spectrometry for Drug Detection. The Analyst 2014, 139 (7), 1740–1750.

Research Areas:

Support Us

We appreciate your financial support. Your gift is important to us and helps support critical opportunities for students and faculty alike, including lectures, travel support, and any number of educational events that augment the classroom experience. Click here to learn more about giving.

Every dollar given has a direct impact upon our students and faculty.

Got More Questions?

Undergraduate inquiries: 

Registration and credit

AP Credit, Section Changes, Overrides,

Graduate inquiries:

Contact Us!

Assistant to the Department Head: Donna Spotts, 706-542-1919 

Main office phone: 706-542-1919 

Main Email:

Head of Chemistry: Prof. Jason Locklin