Solid-phase Microextraction Gas Chromatography-tandem Mass Research Articles

Assessment of genetic diversity and volatile content of commercially grown banana (Musa spp.) cultivars

Banana is an important fruit crop in the tropics and subtropics; however, limited information on biomarkers and signature volatiles is available for selecting commercial cultivars. Clonal fidelity is a major contributor to banana yield and aroma; however, there are no useful biomarkers available to validate clonal fidelity. In this study, we performed the molecular profiling of 20 banana cultivars consisting of diploid (AA or AB) and triploid (AAA or AAB or ABB) genomic groups. We screened 200 molecular markers, of which 34 markers (11 RAPD, 11 ISSR, and 12 SSR) yielded unequivocally scorable biomarker profiles. About 75, 69, and 24 allelic loci per marker were detected for RAPD, ISSR, and SSR markers, respectively. The statistical analysis of molecular variance (AMOVA) exhibited a high genetic difference of 77% with a significant FST value of 0.23 (p < 0.001). Interestingly, the UBC-858 and SSR CNMPF-13 markers were unique to Grand Nain and Ardhapuri cultivars, respectively, which could be used for clonal fidelity analysis. Furthermore, the analysis of banana fruit volatilome using headspace solid-phase microextraction-gas chromatography-tandem mass spectrometry (HS-SPME-GCMS) revealed a total of fifty-four volatile compounds in nine banana cultivars with 56% of the total volatile compounds belonging to the ester group as the significant contributor of aroma. The study assumes significance with informative biomarkers and signature volatiles which could be helpful in breeding and for the authentic identification of commercial banana cultivars.

Quantification of seven microbial volatile organic compounds in human serum by solid-phase microextraction gas chromatography-tandem mass spectrometry

Microbial volatile organic compounds (MVOCs) are primary and secondary metabolites of fungal and bacterial growth. Changes in environmental conditions (e.g., humidity, light, oxygen, and carbon dioxide) influence microbial growth in indoor environments. Prolonged human exposure to MVOCs has been directly associated with sick building syndrome (SBS), respiratory irritation, and asthma-like symptoms. However, no method exists for assessing MVOC exposure by quantifying them in human serum. We developed a novel, high-throughput automated method for quantifying seven MVOCs (3-methylfuran, 2-hexanone, 2-heptanone, 3-octanone, 1-octen-3-ol, 2-ethyl-1-hexanol, and geosmin) in human serum. The method quantifies the target analytes using solid-phase microextraction gas chromatography-tandem mass spectrometry at low parts-per-billion levels. Limits of detection ranged from 0.076 to 2.77 μg/L. This method provides excellent linearity over the concentration range for the analytes, with coefficients of determination >0.992. Recovery in human serum was between 84.5% and 113%, and analyte precision ranged from 0.38% to 8.78%. The intra-day and inter-day reproducibility showed coefficients of variation ≤11% and ≤8%, respectively. Accurate and precise quantification of MVOCs is necessary for detecting and quantifying harmful human exposures in environments with active microbial growth. The method is well suited for high-throughput analysis to aid investigations of unhealthy exposures to microbial emissions.

Suppression of Rhizopus fruit rot by volatile organic compounds produced by Paenibacillus polymyxa CF05

ABSTRACT Volatile organic compounds (VOCs) from a biocontrol bacterium Paenibacillus polymyxa CF05 were evaluated for antifungal effects against Rhizopus stolonifer, an important pathogen causing postharvest fruit rot. The aerial mycelial growth and sporangia production of R. stolonifer was inhibited after exposure to the bacterial VOCs. Moreover, bacterial VOCs exhibited effective inhibition on Rhizopus rots of cherry, mango and nectarine, resulting 75.88%, 60.64% and 73.13% of suppression ratios at 96 h postinoculation (hpi), respectively. However, the suppression ratios were lower than chemical fungicide imazalil. The main volatile compounds from CF05 were analysed by solid-phase microextraction-gas chromatography tandem mass spectrometry (SPME-GC-MS) and 14 compounds were predominately identified. Among them, the volatile compounds benzothiazole and butylated hydroxytoluene exhibited the highest inhibitory effects on R. stolonifer, resulting 0.03 μL mL −1 headspace and 0.04 μL mL −1 headspace of 50% effective concentrations (EC50), respectively. Furthermore, the antagonistic effects of bacterial VOCs were dependent on the cultivation medium, which might be attributed to their various amounts and compositions. In conclusion, the antifungal VOCs from strain CF05 could be a promising agent in the integrated management of Rhizopus fruit rot.

Characterization of Volatile Profiles and Marker Substances by HS-SPME/GC-MS during the Concentration of Coconut Jam.

Characteristic aromas are usually key labels for food products. In this study, the volatile profiles and marker substances of coconut jam during concentration were characterized via sensory evaluation combined with headspace solid phase microextraction-gas chromatography-tandem mass spectrometry (HSPME/GC-MS). A total of 33 aroma compounds were detected by HSPME/GC-MS. Principal component analysis revealed the concentration process of coconut jam can be divided into three stages. In the first stage, esters and alcohols were the two main contributors to the aroma of the coconut jam. Next, a caramel smell was gradually formed during the second stage, which was mainly derived from aldehydes, ketones and alcohols. The concentration of aldehydes increased gradually at this stage, which may be the result of a combination of the Maillard reaction and the caramelization reaction. In the final sterilization stage, the ‘odor intensity’ of caramel reached the maximum level and a variety of aroma compounds were produced, thereby forming a unique flavor for the coconut jam. Finally, furfural fit a logistic model with a regression coefficient (r2) of 0.97034. Therefore, furfural can be used as a marker substance for monitoring the concentration of coconut jam.

A green approach for organophosphate ester determination in airborne particulate matter: Microwave-assisted extraction using hydroalcoholic mixture coupled with solid-phase microextraction gas chromatography-tandem mass spectrometry

Particulate matter (PM) is among the most dangerous air pollutants, and there is a growing concern related to the effects of airborne particles on human health. Their harmful effects can be derived are directly linked to the size of particles themselves and the associated pollutants after they have been taken up by inhalation. In this work was developed a new analytical method for the quantification of organophosphorus esters (OPE) bound to airborne PM. The proposed protocol provides for the microwave-assisted extraction (MAE) of the analytes from the PM followed by solid-phase microextraction gas chromatography-tandem mass spectrometry determination (SPME-GC-MS/MS). Unlike to the traditional protocol, which provides for the use of tedious Soxhlet extraction with environmentally damaging organic solvents, the proposed method allows for a reliable quantification by using an eco-friendly hydroalcoholic mixture (water/ethanol; 50:50, v/v). The method was developed using as target compounds ten organophosphate esters, namely tripropyl phosphate (TPP), tri-n-butyl phosphate (TBP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), tributoxyethyl phosphate (TBEP), triphenyl phosphate (TPhP), 2-ethylhexyl-diphenyl phosphate (EHDPP), tris(2-ethylhexyl) phosphate (TEHP) and tricresyl phosphate (TCP). The extraction performance of five SPME fibers was evaluated and the DVB/CAR/PDMS coating demonstrated to be the most suitable for the extraction of the target analytes. Experimental Design was used for the multivariate optimization of the parameters affecting the MAE process as well as the SPME extraction, and the optimal working conditions were determined by using Derringer's desirability function. The developed method was validated in terms of linearity, sensitivity (LLOQ values of 0.5 ng/mL for TDCPP and 0.1 ng/mL for the other analytes), matrix effect (81–117%), intra and inter day accuracy (83–115% and 80–115%, respectively), and precision (repeatability and reproducibility in the range 1.0–12.4% and 2.3–15.2%, respectively). The satisfactory performances reached make the proposed protocol a green and high-throughput alternative for OPE quantification in particulate matter.

Development and optimization of a solid-phase microextraction gas chromatography–tandem mass spectrometry methodology to analyse ultraviolet filters in beach sand

A methodology based on solid-phase microextraction (SPME) followed by gas chromatography–tandem mass spectrometry (GC–MS/MS) has been developed for the simultaneous analysis of eleven multiclass ultraviolet (UV) filters in beach sand. To the best of our knowledge, this is the first time that this extraction technique is applied to the analysis of UV filters in sand samples, and in other kind of environmental solid samples. Main extraction parameters such as the fibre coating, the amount of sample, the addition of salt, the volume of water added to the sand, and the temperature were optimized. An experimental design approach was implemented in order to find out the most favourable conditions. The final conditions consisted of adding 1 mL of water to 1 g of sample followed by the headspace SPME for 20 min at 100 °C, using PDMS/DVB as fibre coating. The SPME-GC–MS/MS method was validated in terms of linearity, accuracy, limits of detection and quantification, and precision. Recovery studies were also performed at three concentration levels in real Atlantic and Mediterranean sand samples. The recoveries were generally above 85% and relative standard deviations below 11%. The limits of detection were in the pg g−1 level. The validated methodology was successfully applied to the analysis of real sand samples collected from Atlantic Ocean beaches in the Northwest coast of Spain and Portugal, Canary Islands (Spain), and from Mediterranean Sea beaches in Mallorca Island (Spain). The most frequently found UV filters were ethylhexyl salicylate (EHS), homosalate (HMS), 4-methylbenzylidene camphor (4MBC), 2-ethylhexyl methoxycinnamate (2EHMC) and octocrylene (OCR), with concentrations up to 670 ng g−1.