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.

Monitoring of the presence of plasticizers and effect of temperature and storage time in bottled water using a green liquid-liquid microextraction method

In this work, a natural deep eutectic solvent was used for the liquid-liquid microextraction of fourteen phthalates and one adipate from bottled waters. The methodology was validated in terms of matrix effect, linearity, recovery, and limits of quantification (LOQs). Optimum extraction conditions (10 mL of water at pH 8.0 with 100 μL of thymol: menthol 2:1 (n/n) as solvent) provided satisfactory determination coefficients (≥ 0.9977), recovery values (82-127%), and LOQs (0.018-0.523 μg/L). The effects of temperature and storage time on plasticizer presence were studied for 36 different brands stored at 4 °C, room temperature, and 45 °C, and analyzed at 0, 24, 48, 72 h, and 1 week. Only diethyl-, dibutyl-, bis-(2-ethylhexyl) phthalates, and bis-(2-ethylhexyl) adipate were detected. The results showed that there is no relationship between the storage conditions, the bottle material or water carbonation, and the occurrence of these plasticizers, suggesting that residues are introduced during production or by the water supply. The estimated daily intake was lower than the total daily intake set by the European Food Safety Authority.

Quality assessment of environmental water by a simple and fast non-ionic hydrophobic natural deep eutectic solvent-based extraction procedure combined with liquid chromatography tandem mass spectrometry for the determination of plastic migrants

A non-ionic hydrophobic natural deep eutectic solvent (HNADES) based on thymol and menthol was proposed for the liquid-liquid microextraction of fourteen phthalates and one adipate from environmental water samples. Separation, identification, and quantification were achieved by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. The main factors affecting the extraction efficiency were thoroughly studied. Sample pH of 8 and 100 μL of thymol:menthol at molar ratio 2:1 were selected as the best conditions, while ionic strength and type of dispersant solvent were not relevant for the extraction of the target compounds. The whole methodology was validated for treated wastewater, runoff, and pond water matrices, using di-n-butyl phthalate-3,4,5,6-d₄ and dihexyl phthalate-3,4,5,6-d₄ as surrogates. Recovery ranged from 70 to 127% with relative standard deviation values lower than 14%. Limits of quantification of the method were in the range 0.042-0.425 μg/L for treated wastewater, 0.015-0.386 μg/L for runoff, and 0.013-0.376 μg/L for pond water. The methodology was applied for the analysis of real treated wastewater, runoff, and pond water samples from different places of Tenerife and Gran Canaria (Canary Islands) finding the presence of diethyl phthalate, diallyl phthalate, dipropyl phthalate, benzylbutyl phthalate, di-n-butyl phthalate, bis-(2-n-butoxyethyl) phthalate, di-n-pentyl phthalate, dicyclohexyl phthalate, and bis-(2-ethylhexyl) phthalate at concentrations between 105.2 and 3414 ng/L.

Comparison of Pesticide Residue Levels in Red Wines from Canary Islands, Iberian Peninsula, and Cape Verde

In this work, the QuEChERS method coupled to liquid chromatography-time-of flight-mass spectrometry and gas chromatography-triple quadrupole-mass spectrometry were applied for the evaluation of pesticide residues and risk assessment in red wines. The methodologies were successfully validated for 173 pesticides. Recovery values were in the range 75-100% for almost all pesticides and limits of quantification were between 2.60 and 21.39 µg/kg, which are in good agreement with the maximum residue limits (MRLs) established by the European Commission for pesticides in wine grapes. Finally, the analysis of 84 red wine samples from the Canary Islands, the Iberian Peninsula, and Cape Verde was carried out, which found the presence of 31 pesticide residues. However, the risk assessment disclosed that despite the large number of pesticides and the concentrations found, which in some cases exceeded the MRLs, the consumption of these wines, without considering a possible cumulative effect, does not entail a risk to the consumers.

Critical review and re-assessment of analyte protectants in gas chromatography

Despite nearly 80 years of advancements in gas chromatography (GC), indirect chemical matrix effects (MEs), known as the matrix-induced response enhancement effect, still occur to cause a high bias in the GC analysis of susceptible analytes, unless precautions are taken. Matrix-matched calibration is one common option used in GC to compensate for the MEs, but this approach is usually inconvenient, imprecise, and inefficient. Other options, such as the method of standard additions, surface deactivation techniques, chemical derivatizations, priming the GC, and/or use of internal standards, also have flaws in practice. When methods are accommodating, the use of analyte protectants (APs) can provide the best practical solution to not only overcome MEs, but also to maximize analyte signal by increasing chromatographic and detection efficiencies for the analytes. APs address the source of MEs in every injection by filling active sites in the GC inlet, column, and detector, particularly in GC-MS, rather than the analytes that would otherwise undergo degradation, peak tailing, and/or diminished response due to interactions with the active sites. The addition of an adequate amount of APs (e.g. sugar derivatives) to all calibration standards and final extracts alike often leads to lower detection limits, better accuracy, narrower peaks, and greater robustness than the other options to compensate for MEs in GC. This article consists of a critical review of the scientific literature, proposal of mechanisms and theory, and re-evaluation studies involving APs for the first time in GC-orbitrap and GC-MS/MS with a high-efficiency ion source design. The findings showed that 1 µg each of co-injected shikimic acid and sorbitol in the former case, and 1 µg shikimic acid alone in the latter case, led to high quality results in multi-residue analysis of pesticides and environmental contaminants.

Nano-liquid chromatography combined with a sustainable microextraction based on natural deep eutectic solvents for analysis of phthalate esters

The separation of 11 phthalic acid ester (PAEs) was carried out by nano-liquid chromatography coupled to ultraviolet and MS detection. Preliminary experiments were achieved in order to select suitable stationary phases and chromatographic conditions. The baseline separation was obtained, for all compounds, with an XBridge^TM C₁₈ column in less than 15 min, working in step gradient mode. The sensitivity of the method was improved by on-column focusing. PAEs were extracted from alcoholic and nonalcoholic beverages using vortex-assisted emulsification dispersive liquid-liquid microextration and natural deep eutectic solvents. The whole method was validated in terms of linearity, sensitivity, precision, recovery, and repeatability. Combination of both off-line sample preparation preconcentration and large injection volume led to obtain LOQs in the range 5-47 ng/mL. The developed nano-LC-UV method was extended to MS detection to confirm the presence of PAEs in some beverages commercialized in different types of packaging.

A green and simple procedure based on deep eutectic solvents for the extraction of phthalates from beverages

In this work, a green, inexpensive, simple and fast deep eutectic solvent (DES)-based dispersive liquid-liquid microextraction was evaluated, for the first time, for the extraction of phthalates (i.e. benzylbutyl phthalate, diisobutyl phthalate, diisopentyl phthalate, di-n-pentyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate) from different beverages. Separation and determination were achieved by high performance liquid chromatography-diode-array detection while confirmation was carried out by tandem mass spectrometry. The main factors affecting the extraction such as type and volume of DES and emulsifier, pH and ionic strength, were optimised. Choline chloride:phenol-based DES showed the best results. The methodology was validated for tea, apple-based beverage and pineapple juice. Recovery values ranged from 84 to 120% with relative standard deviation values lower than 11%. Limits of detection of the method were in the range 5.1-14.2 µg L^-1 for tea, 5.3-17.8 µg L^-1 for apple beverages and 5.9-15.6 µg L^-1 for pineapple juices.

Nanomaterials as alternative dispersants for the multiresidue analysis of phthalates in soil samples using matrix solid phase dispersion prior to ultra-high performance liquid chromatography tandem mass spectrometry

In this study, the application of different nanomaterials as dispersants in matrix solid phase dispersion has been evaluated for the extraction of fifteen phthalates from different environmental samples prior to their separation and quantification by ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry. Within the evaluated nanomaterials, including graphene oxide, multi-walled carbon nanotubes and iron 1,3,5-benzenetricarboxylate metal-organic framework, the last one showed the best results in terms of extraction capacity and sample clean-up. The effects of the different parameters affecting the sample pretreatment efficiency were exhaustively evaluated. The whole methodology was validated for agricultural soil and sand, using dibutyl phthalate-3,4,5,6-d₄ as surrogate. Recovery values ranged from 70 to 120% for both matrices with RSD values lower than 20% and the limits of quantification of the method achieved were in the range 0.14-2.7 μg/kg dry weight. Finally, the analysis of soil samples from different locations of Tenerife (Canary Islands, Spain) was carried out finding the presence of BBP, DIBP and DBP in the range 5-52 μg/kg dry weight in agricultural soils, and DIPP, DNOP and DINP in the range 2-101 μg/kg dry weight in sand samples.

[The use of suprarenal scintigraphy in the differential diagnosis of suprarenal incidentaloma]

OBJECTIVES

To assess the usefulness of adrenal scintigraphy for clinical evaluation of adrenal incidentalomas, and its relation with pathological diagnosis and follow-up.

PATIENTS AND METHODS

We have studied 46 patients with unilateral adrenal incidentaloma of size between 10 and 100 mm (average 30.5 +/- 19 mm). The lesions were discovered with abdominal computerized tomography in the study of a primary tumor (22%) or in the evaluation of benign pathology (78%). Adrenal scintigraphy assessed uptake in adrenal incidentaloma. Hormonal study included urinary catecholamines, plasma cortisol after dexamethasone, adrenal androgens, and renin and aldosterone in hypertensive patients. Five patients were operated, FNAB was carried out in three patients, and in the rest average follow-up was 29 +/- 21 months. Adrenal incidentaloma was considered nonfunctional if the lesion did not modified its size nor showed analytical alterations along a follow-up higher than 8 months.

RESULTS

Of 46 adrenal lesions, seven didn't show uptake (three metastases, one cyst, one adrenal carcinoma, one pheochromocytoma, and one angiomyolipoma), 34 showed excessive uptake (29 nonfunctional adrenal nodules and 5 hyperfunctional adrenal nodules), and five had normal uptake (nonfunctional adrenal nodules). Adrenal scintigraphy was compatible in all cases with cytological study or the response to chemotherapy. Along the follow-up, growth of the lesion was demonstrated in 23%, and reduction or disappearance of the lesion in 11%, with no hormonal significant changes.

CONCLUSIONS

Detection of a lesion with no uptake in adrenal scintigraphy forces to carry out complementary explorations in order to rule out malignant pathology. A lesion with excessive uptake is indicative of a benign process and should be assessed with hormonal determinations.