Residual determination of anesthetic menthol in fishes by SDME/GC–MS

Efficacy of essential oil from ginger (Zingiber officinale) for anesthesia and transport sedation of pacu (Piaractus mesopotamicus)

This study evaluated the anesthetic and sedative effects of the essential oil of Zingiber officinale (EOZO) on juvenile pacu (Piaractus mesopotamicus). Experiment 1 evaluated concentrations of 0, 50, 100, 200 and 400 mg L-1 EOZO for times of induction and recovery from anesthesia. Furthermore, hematological responses and residual components of EOZO in plasma were determined immediately after anesthesia. Experiment 2 evaluated the effect of 0, 10, 20 and 30 mg L-1 EOZO on water quality, blood variables and residual components of EOZO in plasma and tissues (muscle and liver) immediately after 2 h of transport. Survival was 100%. The three main compounds of EOZO [zingiberene (32.27%), β-sesquiphellandrene (18.42%) and β-bisabolene (13.93%)] were observed in animal plasma and tissues (muscle and liver) after anesthesia and transport, demonstrating a direct linear effect among the evaluated concentrations. The concentration of 200 mg L-1 EOZO promoted surgical anesthesia of pacu and prevented an increase in monocyte and neutrophil levels, yet did not alter other hematological parameters. The use of 30 mg L-1 EOZO has a sedative effect on juvenile pacu, thereby reducing oxygen consumption during transport. Furthermore, the use of 30 mg L-1 EOZO in transport water prevented an increase in hemoglobin and hematocrit, with minimal influences on other blood variables.

Ocimum basilicum essential oil in pacu Piaractus mesopotamicus: anesthetic efficacy, distribution, and depletion in different tissues

This study aimed to evaluate the anesthetic activity of Ocimum basilicum essential oil and the distribution and depletion of its major compounds in different tissues of the pacu, Piaractus mesopotamicus. Juveniles (319.08 ± 9.14 g) were individually anesthetized with six concentrations of essential oil from O. basilicum (150, 180, 210, 240, 270, and 300 mg L-1), while in a second experiment, fish (492.39 ± 51.51 g) were subjected to a 10 min immersion bath with essential oil from O. basilicum (300 mg L-1). After anesthetic recovery, blood and tissue samples of the brain, gills, liver, spleen, and white muscle were collected at 0, 0.5, 1.0, 3.0, 6.0, 12.0, and 24 h. A 300 mg L-1 concentration induced anesthesia in the shortest time (193.11 ± 9.31), while at 270 and 300 mg L-1 concentrations, the anesthetic recovery period was the longest (244.33 ± 12.44) Methyl chavicol and linalool were quantified in all tissue samples. The plasma concentrations of methyl chavicol differed (p < 0.05) at all evaluated times. Linalool decreased (p < 0.05) from 0 to 1 h and decreased again only after 12 h. Reduction percentages in 24 h were 92.9% for methyl chavicol, and 97.2% for linalool. Elimination of the compounds methyl chavicol and linalool is slower in the gills, where lower elimination constants (0.03 and 0.15 per h) and longer half-lives (25.84 and 4.53 h), respectively, are noted. In general, essential oil from O. basilicum compounds was readily eliminated, showing promising potential for use as an anesthetic in aquaculture.

Headspace single drop microextraction based visual colorimetry for highly sensitive, selective and matrix interference-resistant determination of sulfur dioxide in food samples

Excessive intake of SO₂, a widely-used food additive, is able to cause respiratory, cardiovascular and neurological disease. For effectively monitoring SO₂ level, we have developed a headspace single drop microextraction based visual colorimetry for highly sensitive and selective sensing of SO₂ with TMB (3,3',5,5'-tetramethylbenzidine) as a classic chromogenic reagent. A combination of single drop and headspace microextraction integrated merits of high extraction efficiency, low consumption of reagents and excellent matrix interference-resistant ability. The colorimetric principle was based on oxidation of TMB, and SO₂ could compete with TMB to preferentially react with ·OH, resulting in the fading of color blue that could be easily read out by naked eye. LOD was calculated to be 0.53 μM and 5 μM by UV-vis and naked eye, respectively. The method was successfully utilized to analysis of food samples, and the experimental device was miniaturized and easy to construct, thus showing a promising potential in field analysis.

Miniaturized sample preparation techniques and ambient mass spectrometry as approaches for food residue analysis

Analytical methods such as liquid chromatography (LC) and mass spectrometry (MS) are widely used techniques for the analyses of different classes of compounds. This is due to their highlighted capacity for separating and identifying components in complex matrices such food samples. However, in most cases, effective analysis of the target analyte becomes challenging due to the complexity of the sample, especially for quantification of trace concentrations. In this case, miniaturized sample preparation methods have been used as a strategy for analysis of complex matrices. This involves removing the interferents and concentrating the analytes in a sample. These methods combine simplicity and effectiveness and given their miniaturized scale, they are in accordance with green chemistry precepts. Besides, ambient mass spectrometry represents a new trend in fast and rapid analyses, especially for qualitative and screening analysis. However, for complex matrix analyses, sample preparation is still a difficult step and the miniaturized sample preparation techniques show great potential for an improved and widespread use of ambient mass spectrometry techniques. . This review aims to contribute as an overview of current miniaturized sample preparation techniques and ambient mass spectrometry methods as different approaches for selective and sensitive analysis of residues in food samples.

Nanoliter-Scale Droplet-Droplet Microfluidic Microextraction Coupled with MALDI-TOF Mass Spectrometry for Metabolite Analysis of Cell Droplets

The further miniaturization of liquid-phase microextraction (LPME) systems has important significance and major challenges for microscale sample analysis. Herein, we developed a rapid and flexible droplet-droplet microfluidic microextraction approach to perform nanoliter-scale miniaturized sample pretreatment, by combining droplet-based microfluidics, robotic liquid handling, and LPME techniques. Differing from the previous microextraction methods, both the extractant and sample volumes were decreased from the microliter scale or even milliliter scale to the nanoliter scale. We utilized the ability of a liquid-handling robot to manipulate nanoliter-scale droplets and micrometer-scale positioning to overcome the scaling effect difficulties in performing liquid-liquid extraction of nanoliter-volume samples in microsystems. Two microextraction modes, droplet-in-droplet microfluidic microextraction and droplet-on-droplet microfluidic microextraction, were developed according to the different solubility properties of the extractants. Various factors affecting the microextraction process were investigated, including the extraction time, recovery method of the extractant droplet, static and dynamic extraction mode, and cross-contamination. To demonstrate the validity and adaptability of the pretreatment and analysis of droplet samples with complex matrices, the present microextraction system coupled with MALDI-TOF mass spectrometry (MS) detection was applied to the quantitative determination of 7-ethyl-10-hydroxylcamptothecin (SN-38), an active metabolite of the anticancer drug irinotecan, in 800-nL droplets containing HepG2 cells. A linear relationship (y = 0.0305x + 0.376, R² = 0.984) was obtained in the range of 4-100 ng/mL, with the limits of detection and quantitation being 2.2 and 4.5 ng/mL for SN-38, respectively.

Direct immersion single-drop microextraction of semi-volatile organic compounds in environmental samples: A review

Single-drop microextraction (SDME) techniques are efficient approaches to pretreatment of aqueous samples. The main advantage of SDME lies in the miniaturization of the solvent extraction process, minimizing the hazards associated with the use of toxic organic solvents. Thus, SDME techniques are cost-effective, and represent less harm to the environment, subscribing to green analytical chemistry principles. In practice, two main approaches can be used to perform SDME - direct immersion (DI)-SDME and headspace (HS)-SDME. Even though the DI-SDME has been shown to be quite effective for extraction and enrichment of various organic compounds, applications of DI-SDME are normally more suitable for moderately polar and non-polar semi-volatile organic compounds (SVOCs) using organic solvents which are immiscible with water. In this review, we present a historical overview and current advances in DI-SDME, including the common analytical tools which are usually coupled with DI-SDME. The review also focuses on applications concerning SVOCs in environmental samples. Currents trends in DI-SDME and possible future direction of the procedure are discussed.

Methodology development based on "dilute and shoot" and QuEChERS for determination of multiple mycotoxins in cocoa by LC-MS/MS

This work proposes an extraction method based on the "dilute and shoot" approach and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) for the simultaneous determination of 42 mycotoxins (34 quantified and 8 qualitatively studied) in dried cocoa bean samples. The purpose of the developed methodology was the reduction of co-extractives from the matrix and an efficient extraction without a cleanup step, and subsequent analysis by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). In order to obtain the best extraction conditions, gravimetric tests were performed and parameters that influenced the extraction efficiency were evaluated, such as the proportion of extraction phases, amount of salt, acidification, and extraction time. The performance of the developed method was evaluated to ensure its reliability. Considering the recovery range of 70-120% as an accuracy parameter, four of the mycotoxins under study (acetyl T-2, tenuazonic acid, wortmannin, and zearalenone) showed undesirable values at one of the levels evaluated. The repeatability of the method was assessed for 34 mycotoxins by the relative standard deviation (RSD%) of the responses, and all presented satisfactory values. The quantification limits ranged from 1.0 to 33.0 μg kg^-1. Modification of the extraction methods made it possible to simultaneously analyze multiple mycotoxins, eliminating the need for the cleanup step, which led to analyte losses. The proposed methodology has a low cost, which makes it advantageous in routine analysis. It also has the potential for scope extension to cocoa-based foods, which are naturally exposed to a greater variety of mycotoxins. Graphical abstract.

Simultaneous detection of five flavoring agents in chewing gum by ultrasound-microwave synergistic extraction coupled with gas chromatography

So far, the identification and determination of flavor additives in food has gained extensive attention in the area of food safety. However, it remains a big challenge for simultaneous detection of diverse flavor agents. In this work, a novel gas chromatography method coupled with ultrasound-microwave synergistic extraction was developed for simultaneous detection of five flavor compounds, including butyl butyrate, menthol, methyl salicylate, eugenol and vanilline. In this strategy, ultrasound-microwave synergistic extraction was used to extract the five flavoring agents from chewing gum. The effects of extractants, solid-liquid ratio, extraction time and microwave power on extraction yield were researched by using orthogonal test. After the optimization of programme temperature and splitless injection, the five flavoring agents were well separated and simultaneously detected with wide linear ranges, low limits of detection, high accuracy and good repeatability. Therefore, this proposed method would hold great promise for assay application on the food safety.

Current direction and advances in analytical sample extraction techniques for drugs with special emphasis on bioanalysis

Analytical techniques may not be compatible or sufficiently sensitive to the analytes, unless it undergoes a specific sample extraction procedure. Sample extraction can be considered as one of the key steps in analysis. Analysis of a poorly treated sample may produce inferior quality of analytical data. Continuous advancement and development of newer sample extraction techniques such as solid phase microextraction, ultrasound, magnetically and microwave assisted magnetic extraction; electro-membrane extraction and dried blood spotting are to address the shortcomings of the existing techniques and to provide more automation, minimizing preparation time and make them high throughput. This review summarizes the suitability of application of the advanced sample preparation techniques available for chemical and bioanalysis in a comprehensive manner. This review also provides a scientific guidance for selecting the appropriate sample extraction technique based on sample type.

Current trends on microextraction by packed sorbent – fundamentals, application fields, innovative improvements and future applications

MEPS, the acronym of microextraction by packed sorbent, is a simple, fast and user- and environmentally-friendly miniaturization of the popular solid-phase extraction technique (SPE).