Evaluation of pre-concentration techniques for gas chromatographic determination of low amounts of volatile contaminants and degradation products
Examensarbete för masterexamen
Biotechnology (MPBIO), MSc
The project investigated the compared two pre-concentration methods, Thermal Desorption System (TDS) coupled to a Thermal Extractor (TE) and Multiple Headspace Injection (MHI) using a Multiple Purpose Sampler (MPS) for detecting volatile amines in solid pharmaceutical products and synthesis precursor chemicals samples. The TDS-TE and MHI extractions are directly injected into a Cold Injection System (CIS). The CIS captures the analytes using cold temperatures to condense the vapours. The sample is then injected into a gas chromatograph-mass spectrometer system. The resulting mass spectrum extracted from the chromatogram can then be used in coordination with a mass spectral library with search program to identify amines present in the samples. The two pre-concentration methods were compared based on sensitivity to detect odorous amines, overall analyses time and general ease of use. The TE-TDS method was more labour intensive and required longer analyses times but resulted in higher sensitivity, ability to detect most amines and ability to adapt to smaller sample sizes and lower concentrations in the sample. MHI by contrast is easier to use as the MPS is largely automated and faster but the sensitivity might not be sufficient for detecting volatile amines in solid pharmaceutical products. The TDS-TE method is preferable due to greater sensitivity, and further work should be done to increase the automation of this pre-concentration method.
Analytisk kemi , Miljövetenskap , Analytical Chemistry , Environmental Sciences