Date of Award

Summer 8-2021

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)


Mathematics and Natural Sciences

Committee Chair

Dr. Xuyang He

Committee Chair School

Criminal Justice, Forensic Science, and Security

Committee Member 2

Dr. Song Guo

Committee Member 2 School

Mathematics and Natural Sciences

Committee Member 3

Dr. Wujian Miao

Committee Member 3 School

Mathematics and Natural Sciences


Applications of SLE (supported liquid extraction) is a relatively new extraction technique that is not widely used in forensic toxicology. SLE is also easier and less time consuming than traditional LLE (liquid-liquid extraction) and SPE (Solid phase extraction). This work will compare the extraction efficiencies between SLE and SPE for methamphetamine from urine with detection and quantitation using GC-MS (gas chromatography- mass spectrometry). The SLE cartridges provide better analyte recoveries, eliminate emulsion formation, and allow for shorter processing time than other extraction techniques. The SPE cartridges used have a mixed-mode non-polar/strong cation exchange retention mechanism to extract basic analytes like MA from urine and other aqueous samples. Optimal retention for SLE was obtained by modifying the urine samples two pH units below the pKa of MA by ensuring the amine groups are properly charged to adhere to the SPE sorbent.

Both SPE and SLE calibration range was determined to be 0.5 mg/L to 15 mg/L. MA recovery from urine was better from SPE than SLE with higher accuracy, precision, and extraction efficiency. SPE also demonstrated better linearity. The LOD and LOQ were determined to be 0.25 mg/L for both SLE and SPE. For the extraction of MA from urine, SPE was found to be the preferred method.