The impact of infrared radiation, solar radiation, and burial exposure on the efficacy of forensic immunoassay testing for blood, semen, and saliva.

Determining the biological source of a stain can be important information for both investigators and the judiciary in criminal cases. Immunochromatographic assays are commonly used in forensic science for the identification of human biological material. It has previously been demonstrated that various environmental, thermal and chemical insults can affect the efficacy of ABAcard® HemaTrace® in the detection of human blood. In this study, the efficacy of three tests - ABAcard® HemaTrace®, ABAcard® p30, and RSID™-Saliva - was determined for the detection of blood, semen, and saliva respectively, after the fluids had been exposed to adverse environmental conditions. Each biological fluid was deposited on cotton swatches and exposed to infrared (IR) light using a 100 W heat lamp emitting IR light between 620 and 750 nm and heat of 32° for 24, 36 and 48 h. Cotton swatches bearing biological fluids were also buried in outdoor soil for 3, 4 and 5 weeks. To test common forensic scenarios where biological material may be exposed to solar light, samples were placed on a car bonnet and left for 24, 36 and 48 h. ABAcard® HemaTrace® was able to detect haemoglobin in blood that had been exposed to IR and solar light up to 48 h. False negative ABAcard® HemaTrace® results were obtained from 60 % of blood samples buried for 3 and 4 weeks, and 80 % of blood samples buried for 5 weeks. ABAcard® p30 was able to detect p30 in semen that had been exposed to IR and solar light up to 48 h, except for one false negative after 48 h of IR exposure. False negative ABAcard® p30 results were obtained from all semen samples buried for 3, 4 and 5 weeks. RSID™-Saliva was able to detect α-amylase in saliva in all instances, with no false negative results observed. The findings from this study highlight the need to consider the context in which human blood, semen and saliva are found when reporting on negative immunoassay results.

The identification of synthetic cannabinoids surface coated on herbal substrates using solid-state nuclear magnetic resonance spectroscopy.

Solid-state 13C and 19F NMR spectroscopy offers a non-destructive, highly selective protocol for the identification of forensically relevant synthetic cannabinoids on herbal substrates. Using this technique, well resolved 13C spectra were obtained that readily enabled structural identification; in some instances complemented by 19F spectral data. The approach described has potential for related applications such as the direct detection of pesticides on plants.

Improving quantification using curtain flow chromatography columns in the analysis of labile compounds: a study on amino acids.

The performance of curtain flow chromatography column technology with MS detection was evaluated for the analysis of labile compounds. The curtain flow column design allows for separations that are faster and/or more sensitive than conventional columns, depending on how exactly the curtain flow column is configured. For example, when mass spectral detection is employed, the curtain flow column can yield separations that are 5-times faster than conventional columns when the curtain flow and the conventional columns have the same internal diameter. Or when the internal diameter of the conventional column is reduced in order to yield the same analytical through-put as the curtain flow column, the sensitivity on the curtain flow column can be as much as 66-fold higher than the conventional column. As a consequence of the higher analytical through-put less standardization is required in the analysis of labile compounds because less sample degradation is apparent. Consequently the sample integrity is preserved yielding data of a higher quality.

High through-put and highly sensitive liquid chromatography-tandem mass spectrometry separations of essential amino acids using active flow technology chromatography columns.

A preliminary investigation was undertaken to assess the performance of a new chromatography column technology in applications involving liquid chromatography coupled to mass spectrometry. The new column design allows mobile phase and solute to be extracted from the radial central region of the column, which reduces the solvent load to the mass spectrometer and improves separation efficiency. Effectively the column functions as a 'wall-less' column. The advantages of this design is that the analysis through-put can be increased by a factor of five, while at the same time there is a reduction in baseline noise, which results in an increase in the signal to noise response by up to 10-fold in comparison to standard columns with the same internal diameter and approaching 66-fold in comparison to standard columns with the same virtual internal diameter.

The concentration of oleocanthal in olive oil waste.

The aim of this study was to determine the concentration of oleocanthal in olive pomace waste and compare this to its concentration in extra-virgin olive oil (EVOO). The concentration of oleocanthal in freshly pressed EVOO and its subsequent waste was analysed at early, mid and late season harvests. Oleocanthal concentrations were quantified using high-performance liquid chromatography-mass spectrometry. In oil, oleocanthal concentration was as follows: 123.24 ± 6.48 mg kg(-1) in early harvest, 114.20 ± 17.42 mg kg(-1) in mid harvest and 152.22 ± 10.54 mg kg(-1) in late harvest. Its concentration in waste was determined to be: 128.25 ± 11.33 mg kg(-1) in early harvest, 112.15 ± 1.51 mg kg(-1) in mid harvest and 62.35 ± 8.00 mg kg(-1) in late harvest. Overall, olive pomace waste is a valuable source of oleocanthal.

Partial least squares and principal components analysis of wine vintage by high performance liquid chromatography with chemiluminescence detection.

HPLC with acidic potassium permanganate chemiluminescence detection was employed to analyse 17 Cabernet Sauvignon wines across a range of vintages (1971-2003). Partial least squares regression analysis and principal components analysis was used in order to investigate the relationship between wine composition and vintage. Tartaric acid, vanillic acid, catechin, sinapic acid, ethyl gallate, myricetin, procyanadin B and resveratrol were found to be important components in terms of differences between the vintages.

Geographical classification of some Australian wines by discriminant analysis using HPLC with UV and chemiluminescence detection.

HPLC with UV and acidified potassium permanganate chemiluminescence detection, combined with multivariate data analysis techniques, were used for the geographical classification of some Australian red (Cabernet Sauvignon) and white (Chardonnay) wines from two regions (Coonawarra and Geelong). Identification of the wine constituents prominent in the chromatography was performed by mass spectrometry. Principal components analysis and linear discriminant analysis were used to classify the wines according to region of production. Separation between regions was achieved with both detection systems and key components leading to discrimination of the wines were identified. Using two principal components, linear discriminant analysis with UV detection correctly classified 100% of the Chardonnay wines and, overall 91% of the Cabernet Sauvignon wines. With acidified potassium permanganate chemiluminescence detection, 75% of the Chardonnay wines and 94% of the Cabernet Sauvignon wines were correctly classified using two factors.