Ultrafast laser diode thermal desorption method for analysis of representative pharmaceuticals in soil leachate samples.
We developed and evaluated a novel analytical method combining ambient ionization technique laser diode thermal desorption with chemical ionization (LDTD APCI) and tandem mass spectrometry detection. The LDTD/APCI MS/MS method was developed for determination of representative pharmaceuticals from different classes (carbamazepine, sulfamethoxazole, irbesartan, fexofenadine) in leachate samples from soil sorption experimentation. We then optimized laser pattern, laser energy and spiked sample volume, which are crucial parameters for this LDTD/APCI MS/MS method. We further identified utility of a chelating agent (Na2 EDTA) to obtain the highest achievable and reproducible signal of target analytes. Achieved method performance parameters (LODs, LOQs, trueness and precision) were comparable with those obtained from LC MS/MS. However, application of this novel LDTD/APCI MS/MS method reduced analysis time by two orders of magnitude (to 12 s) compared to more conventional LC MS/MS approaches, without use of organic solvents. We expect this novel method will reduce costs and increase throughput for future analyses of pharmaceuticals in the environment while advancing a timely principle of green chemistry.
Talanta