Exploring the Use of Switchable Hydrophilicity Solvents as Extraction Phase for the Determination of Food-Packaging Contaminants in Coconut Water Samples by Gas Chromatography-Mass Spectrometry

Eco-friendly approach developed for the microextraction of xenobiotic contaminants from tropical beverages using a camphor-based natural hydrophobic deep eutectic solvent

In this work, an innovative green strategy has been developed for the analysis of twenty-seven endocrine disruptors, including bisphenols, alkylphenols and alkylphenol ethoxylates, phthalic acid esters and one adipate in tropical beverages. For this purpose, nine natural hydrophobic deep eutectic solvents based on the terpenoids camphor, thymol and menthol at different molar ratios were investigated for the first time as extractants for the liquid-liquid microextraction of the target analytes from coconut waters and Aloe Vera drinks. A mixture of camphor:thymol at molar ratio 1:2 (n/n) was selected as extraction solvent. Determination of the target analytes was carried out by ultra-high performance liquid chromatography coupled to tandem mass spectrometry. After optimisation of the determination and extraction conditions, the methodology was validated achieving good results in terms of linearity, as well as recovery values in the range 75-111% and limits of quantification from 0.137 to 10.08 μg/L. Finally, the developed methodology was applied to the analysis of commercially available samples, finding the presence of diethyl phthalate.

The environmental sources of benzophenones: Distribution, pretreatment, analysis and removal techniques

Benzophenones (BPs) have wide practical applications in real human life due to its presence in personal care products, UV-filters, drugs, food packaging bags, etc. It enters the wastewater by daily routine activities such as showering, impacting the whole aquatic system, then posing a threat to human health. Due to this fact, the monitoring and removal of BPs in the environment is quite important. In the past decade, various novel analytical and removal techniques have been developed for the determination of BPs in environmental samples including wastewater, municipal landfill leachate, sewage sludge, and aquatic plants. This review provides a critical summary and comparison of the available cutting-edge pretreatment, determination and removal techniques of BPs in environment. It also focuses on novel materials and techniques in keeping with the concept of "green chemistry", and describes on challenges associated with the analysis of BPs, removal technologies, suggesting future development strategies.

A new application of the switchable hydrophilicity solvent-based homogenous liquid-liquid microextraction to analyze synthetic cannabinoids in plasma by LC-MS/MS

Synthetic cannabinoids are still a growing trend among drug users and consist of a group of hundreds of highly potent compounds. To investigate the use of such substances, sample preparation of biological matrices is a crucial step prior to instrumental analysis. Although different efficient extraction techniques have been proposed for that aim, they usually do not fit eco-friendly guidelines that have been gaining popularity in recent years, such as Green Analytical Toxicology. This work uses describes for the first time the use of switchable hydrophilicity solvent-based homogenous liquid-liquid microextraction (SHS-HLLME) for synthetic cannabinoids. This is a green technique that replaces highly toxic organic reagents for switchable hydrophilicity solvents (SHS), substances that can be either water-miscible or immiscible depending on their protonation. Thus, by simply adjusting the pH of the system, these SHS can be used as extraction solvents. A full optimization study including type of SHS, volume of protonated SHS, volume of NaOH, salting-out effect, and extraction time was performed. The optimized procedure consisted of precipitating the proteins of 300 µL of plasma with 300 µL of acetonitrile followed by centrifugation; evaporation of the organic solvent under N2 stream; addition of 500 µL of the protonated DPA, DPA-HCl (6 M) (1:1, v/v); addition of 500 µL of NaOH (10 M); and finally centrifugation and evaporation. Validation results showed determination coefficients ≥ 0.99 for the 0.1-10 ng/mL linear range; 0.01-0.08 ng/mL as limit of detection; 0.1 ng/mL as limit of quantitation; accuracy and imprecision were within acceptable ranges; matrix effect, recovery, and process efficiency ranged from -55.6 to 185.9%, 36-56.7%, and 18.5-148.4%, respectively. The SHS-HLLME herein described was fully optimized providing satisfactory recoveries of 31 synthetic cannabinoids at low concentrations requiring only 300 µL of plasma. In addition, the validation results showed that the technique is a reliable eco-friendly alternative for clinical and toxicological analysis.

A Review of the Analysis of Phthalates by Gas Chromatography in Aqueous and Food Matrices

As a commonly well-known industrial chemical, phthalates are produced in high volumes to be used in various consumer products (e.g., plasticizers, medical devices, construction materials, and toys) to enhance softness, durability, transparency, and flexibility. Phthalates are generally not chemically bonded to the polymer chain of the plastic in which they are mixed. Thus, they may leach, migrate, or evaporate into indoor/outdoor air, and foodstuffs. In this review, a comprehensive overview of several sample preparation methods coupled with gas chromatography for the analysis of phthalates in various kinds of complex matrices, with a focus on the last 20 years' worth of papers. The review begins by highlighting the environmental significance of phthalate pollution along with the various routes to their exposure to general population. Then, the discussion is extended to cover the pretreatment and extraction techniques for phthalates for their quantitation based on gas chromatographic approach. Finally, the present and future challenges for the detection of phthalates in aqueous and food matrices are discussed.

Application of Homogeneous Liquid-Liquid Microextraction with Switchable Hydrophilicity Solvents to the Determination of MDMA, MDA and NBOMes in Postmortem Blood Samples

Synthetic drugs for recreational purposes are in constant evolution and their consumption promote a significant increase in intoxication cases, resulting in damaging public health. The development of analytical methodologies to confirm the consumption of illicit drugs in biological matrices are required for control of these substances. This work exploited the development of an extraction method based on homogenous liquid-liquid microextraction with switchable hydrophilicity solvent as extraction phase (SHS-HLLME) for the determination of the synthetic drugs MDMA, MDA and NBOMes (25B, 25C and 25I) in postmortem blood, followed by liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS). The optimized sample preparation conditions consisted of using 250 µL of ZnSO4 10% and 50 µL of NaOH 1 mol/L in the protein precipitation step; N,N-dimethylcyclohexylamine (DMCHA) was used as switchable hydrophilicity solvent (SHS), 650 μL of a mixture of SHS:HCl 6 mol/L (1:1 v/v), 500 μL of whole blood, 500 μL of NaOH 10 mol/L and 1 min of extraction time. The proposed method was validated, providing determination coefficients higher than 0.99 for all analytes; LOD and LOQ ranged from 0.1 to 10 ng/mL; intra-run precision from 2.16 to 9.19%; inter-run precision from 2.39 to 9.59%; bias from 93.57 to 115.71%; and matrix effects from 28.94 to 51.54%. The developed method was successfully applied to four authentic postmortem blood samples from synthetic drugs users, and it was found to be reliable with good selectivity.