Author Identifier
Date of Award
2026
Keywords
GC/MS/MS, hair, GHB, forensic science, method development
Document Type
Thesis
Publisher
Edith Cowan University
Degree Name
Master of Science by Research
School
School of Science
First Supervisor
Hayley Abbiss 
0000-0002-6821-5564
Second Supervisor
Armaghan Shafaei Darestani 0000-0002-5763-531X
Third Supervisor
Joel Gummer 0000-0002-3609-3398
Abstract
Gamma (γ)-hydroxybutyrate (GHB) is an endogenous short-chain fatty acid, and is of forensic importance due to its use in drug facilitated sexual assault (DFSA). Exogenous GHB has a limited window of detection in blood (1-hour) and urine (12-hours). Testing hair allows detection of drugs months after ingestion. This thesis contains a literature review which compares published methods which determine concentration of endogenous GHB in hair to determine which procedures are suitable for experimental comparison. The aims of this thesis were to develop a GC-MS-based method for the detection of GHB, test various methods to improve extraction, determine linearity, precision, accuracy, limit of detection, limit of quantification, and recovery for the developed method, and use the validated method to analyse GHB content of human hair samples. Three GC-MS gradient methods were tested to determine which produced the best peak shape and efficient chromatic separation. Salting and double extraction did not produce a significantly (p = 0.731) different result, the homogeniser did not produce a significant (p = 0.4824) result over hand mixing but was shown to be faster and have an improved throughput of 2 minutes instead of 20 minutes per batch (n=21). Linearity was determined using two external calibration curves performed on different days which had R2 values of 0.9621 and 0.9869 respectively. Precision was determined by calculating the %RSD of the response ratio for each concertation of a seven-point external calibration curve, which produced precision values (%RSD) in the range 7.03% – 102.11%. Accuracy was determined to be 2351.5%. by calculating the GHB concentration in hair using an external calibration method (12.45 ng/mg) compared to standard addition (0.508 ng/mg). Limit of detection and limit of quantification were estimated using an external calibration curve and were determined to be 0.10 and 0.33 ng/µL respectively. Recovery was calculated by spiking hair with GHB at multiple concentrations and was determined to be between 97.0% and 1022.3%. The method developed showed some promising results however, it will require future work to produce a method which meets the validation criteria. Further optimisations of this method may include, further clean-up of the sample with the use of solid phase extraction (SPE), and acquisition using a LC-MS/MS as this would remove the need for BSTFA which may reduce any coelution.
Recommended Citation
Keller, J. R. (2026). Development and evaluation of a GC-MSMS method for the quantification of gamma hydroxybutyrate in hair. Edith Cowan University. https://doi.org/10.25958/4qz3-0m60