Extraction of pesticides, dioxin-like PCBs and PAHs in water based commodities using liquid–liquid microextraction and analysis by gas chromatography–mass spectrometry

An analytical approach to determine the health benefits and health risks of consuming berry juices

Food products composition analysis is a prerequisite for verification of product quality, fulfillment of regulatory enforcements, checking compliance with national and international food standards, contracting specifications, and nutrient labeling requirements and providing quality assurance for use of the product for the supplementation of other foods. These aspects also apply to the berry fruit and berry juice. It also must be noted that even though fruit juices are generally considered healthy, there are many risks associated with mishandling both fruits and juices themselves. The review gathers information related with the health benefits and risk associated with the consumption of berry fruit juices. Moreover, the focus was paid to the quality assurance of berry fruit juice. Thus, the analytical methods used for determination of compounds influencing the sensory and nutritional characteristics of fruit juice as well as potential contaminants or adulterations.

Spatial and seasonal distribution of pesticides in the waters of Azagny area (Grand Lahou, Cote d'Ivoire)

This study provides comprehensive data on the seasonal variation and distribution of pesticides in the waters bordering Azagny National Park (ANP). Forty-six (46) samples of water from the Azagny area were analyzed using high-performance liquid chromatography (HPLC) coupled with a UV/visible detector to assess the level of thirty-one pesticide molecules divided into six families. These include triazines, phenylureas, organophosphates, carbamates, chloroacetanilides, dicarboximides, and crimidine, which are regularly used in this area. The respective average concentrations of pesticides are 54.54 µg//L, 20.93 µg/L, 18.24 µg/L, 3.06 µg/L, and 16.52 µg/L in the Bandama, Azagny Canal, ANP, mangroves, and estuarine environment. The analyses also showed that herbicides were the most abundant pesticides in the three waters, Bandama, Azagny Canal, and Azagny Park, with levels of 100%, 63%, and 59%, respectively, followed by insecticides with a levels of 0%, 37%, and 41%, respectively. However, rodenticides (76%) were more frequently detected than herbicides (24% in the mangroves). Regarding seasonal variation, high levels of pesticides were detected in the Bandama River, the Azagny Canal, and the mangroves during the dry season, while multiple pesticide residues were detected during the rainy season. The waters bordering Azagny National Park (ANP) are contaminated with pesticide residues (triazines, phenylureas, organophosphates, carbamates, and chloroacetanilides). As a result, policymakers should implement measures to regularly monitor pesticide levels in plantations surrounding the Azagny region's waters in order to better preserve biodiversity.

A sensitive microextraction by packed sorbent-gas chromatography-mass spectrometry method for the assessment of polycyclic aromatic hydrocarbons contamination in Antarctic surface snow

For the first time an eco-friendly method involving microextraction by packed sorbent (MEPS) coupled to gas chromatography-mass spectrometry (GC-MS) was developed for the determination of the 16 US-EPA priority pollutant polycyclic aromatic hydrocarbons (PAHs) as indicators of anthropogenic contamination in snow samples collected in polar regions. MEPS was carried out by using C8 sorbent material packed in a barrel insert and needle (BIN) and integrated in the eVol® semi-automatic device. For optimization purposes a Face Centred Design and the multicriteria method of the desirability functions were performed to investigate the effect of some parameters affecting the MEPS extraction efficiency, i.e. the number of loading cycles and the number of elution cycles. The developed MEPS-GC-MS method proved to be suitable for PAHs analysis at ultra-trace level by extracting small sample volumes achieving detection limits for 16 PAHs in the 0.3-5 ng L^-1 range, repeatability and intermediate precision below 11% and 15%, respectively, and good recovery rates in the 77.6 (±0.1)-120.8 (±0.1)% range for spiked blank snow samples. Enrichment factors in the 64 (±7)-129 (±18) range were calculated. Finally, the proposed method was successfully applied to the determination of PAHs in surface snow samples collected in 2020-2021 from four locations of Northern Victoria Land, Antarctica. Local emission sources such as ships and research stations were found to influence PAHs concentrations in the surface snow.

Simultaneous determination of forty-two parent and halogenated polycyclic aromatic hydrocarbons using solid-phase extraction combined with gas chromatography-mass spectrometry in drinking water

The coexistence of parent polycyclic aromatic hydrocarbons (PPAHs) and halogenated PAHs (HPAHs) in drinking water has generated much concern recently. However, a method to simultaneously determine these compounds has not been developed. In this study, a method using solid-phase extraction combined with gas chromatography-mass spectrometry for determination of PPAHs and HPAHs in drinking water was established. Forty-two target compounds including 16 PPAHs and 26 HPAHs (16 chlorinated PAHs (Cl-HPAHs) and 10 brominated PAHs (Br-PAHs)) were selected to evaluate the performance. Our results indicate enriching compounds with a LC18 cartridge and eluting with dichloromethane is optimal with recovery of 74.88-119.4%. Method detection limits ranged from 0.34 to 3.37 ng L^-1 when only using 1 L samples. The method accomplished the analysis of trace PPAHs and HPAHs. We found the coexistence of PPAHs and HPAHs including 12 PPAHs, 2 Cl-PAHs and 3 Br-PAHs in tap water samples. Maximum total concentration of PPAHs and HPAHs reached 33.69 ng L^-1 and 3.04 ng L^-1, respectively. Trace Br-PAHs were first detected in drinking water. 6-bromobenzene[a]pyrene was dominated among the HPAHs with a concentration from 2.30 to 2.69 ng L^-1. The simultaneous occurrence of PPAHs and HPAHs in drinking water should receive more attention, and their formation mechanism should be further explored.

Measurement uncertainty assessment of magnesium trisilicate column for determination of Sudan colorants in food by HPLC using C8 column

This study aimed to conduct measurement uncertainty assessment of a new method for determination of Sudan colorants (Sudan I, II, III and IV) in food by high performance liquid chromatography (HPLC). Samples were extracted with organic solvents (hexane, 20% acetone) and first purified by magnesium trisilicate (2MgO·3SiO2). The Sudan colorants (Sudan I-IV) were also initially separated on C8 by gradient elution using acetonitrile and 0.1% (v/v) formic acid aqueous solution as the mobile phases and detected with diode-array detector (DAD). The uncertainty of mathematical model of Sudan I, II, III and IV is based on EURACHEM guidelines. The sources and components of uncertainty were calculated. The experiment gave a good linear relationship over the concentration from 0.4 to 4.0 μg/mL and spiked recoveries were from 74.0% to 97.5%. The limits of determination (LOD) were 48, 61, 36, 58 μg/kg for the four analytes, respectively. The total uncertainty of Sudan colorants (Sudan I, II, III and IV) was 810±30.8, 790±28.4, 750±27.0, 730±50.0 μg/kg, respectively. The recovery uncertainty was the most significant factor contributing to the total uncertainty. The developed method is simple, rapid, and highly sensitive. It can be used for the determination of trace Sudan dyes in food samples. The sources of uncertainty have been identified and uncertainty components have been simplified and considered.

Ultrasonic nebulisation extraction: extraction column coupled with liquid phase microextraction for analysis of the volatile organic compounds in Foeniculum vulgare Mill. as a model

INTRODUCTION

As the concentrations of the volatile organic compounds are always low and their matrix is complex, it is necessary to pre-concentrate the volatile organic compounds before analysis. Ultrasonic nebulisation extraction with a self-made extraction column coupled with liquid phase microextraction is developed for the extraction of active constituents from spices.

OBJECTIVE

To develop an environmentally compatible extraction technique for the preparation and analysis of the volatile organic compounds from spices.

METHOD

The sample is placed into the nebulisation vessel of a nebulisation humidifier and a purging gas is blown through the vessel continuously. When the nebuliser is switched on, a ultrasonic fountain is formed by ultrasonic vibration and the target analytes are transferred from the sample solution to the vapour phase and then concentrated on the extraction solvent in the extraction column. After extraction for 3 min and allowed to stand upright for 5 min, the extract is analysed by GC and GC-MS. Different methods of comparison can then be carried out.

RESULTS

Optimum conditions were found to be: 30 μL of n-tetradecane as the extraction solvent, a flow rate for the purging gas of 40 mL/min, a purging time of 3 min and a standing time was 5 min. The contents of constituents in the extract obtained by the proposed method were close to those obtained by hydrodistillation (HD). Moreover, the proposed method achieves higher enrichment efficiency.

CONCLUSION

A method was developed for the extraction of volatile organic compounds from spices. The study has shown that it is a fast and environmentally sustainable technique.

Simultaneous determination of polycyclic aromatic hydrocarbons and benzene, toluene, ethylbenzene and xylene in water samples using a new sampling strategy combining different extraction modes and temperatures in a single extraction solid-phase microextraction-gas chromatography-mass spectrometry procedure

This study proposes a new optimization approach for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and xylene isomers (BTEX) from water samples using the solid-phase microextraction technique followed by gas chromatography-mass spectrometry (GC-MS) separation and detection. The objective of the study was to achieve compromise extraction conditions, suitable for all semi-volatile and volatile compounds, under which the amount extracted is maximized for all analytes. This was achieved by careful optimization of the fiber coating, salting-out effect, extraction time and temperature and extraction mode (headspace or direct immersion). With the optimized fiber coating - PDMS/DVB 65 μm - the other selected factors were optimized using a response surface methodology through central composite designs. As expected, the optimized results for each class of analytes varied significantly, probably due to the differences in their volatility and the equilibrium constants for the analyte/fiber coating. In order to overcome this issue, a new optimization approach was proposed based on a combination of extraction modes and extraction temperatures in a single extraction procedure. The final optimized procedure was: 48 min of extraction in direct immersion mode with the sample maintained at 80 °C followed by a further 32 min of headspace extraction with the sample temperature kept at 10 °C. The proposed procedure was compared with conventional methods based on the use of a single extraction mode and temperature (80 min of headspace extraction at 60 °C or 80 min of direct immersion extraction at 50 °C). The newly proposed method was shown to be more attractive as it extracted higher amounts of both semi-volatile and volatile compounds in a single extraction procedure compared to the conventional approaches. The optimized method was validated and excellent results were obtained.