A novel honeycomb-like 3D-printed device for rotating-disk sorptive extraction of organochlorine and organophosphorus pesticides from environmental water samples.

In this study, 3D-printing based on fused-deposition modeling (FDM) was employed as simple and cost-effective strategy to fabricate a novel format of rotating-disk sorptive devices. As proof-of-concept, twenty organochlorine and organophosphorus pesticides were determined in water samples through rotating-disk sorptive extraction (RDSE) using honeycomb-like 3D-printed disks followed by gas chromatography coupled to mass spectrometry (GC-MS). The devices that exhibited the best performance were comprised of polyamide + 15 % carbon fiber (PA + 15 % C) with the morphology being evaluated through X-ray microtomography. The optimized extraction conditions consisted of 120 min of extraction using 20 mL of sample at stirring speed of 1100 rpm. Additionally, liquid desorption using 800 µL of acetonitrile for 25 min at stirring speed of 1100 rpm provided the best response. Importantly, the methodology also exhibited high throughput since an extraction/desorption platform that permitted up to fifteen simultaneous extractions was employed. The method was validated, providing coefficients of determination higher than 0.9706 for all analytes; limits of detection (LODs) and limits of quantification (LOQs) ranged from 0.15 to 3.03 µg L-1 and from 0.5 to 10.0 µg L-1, respectively. Intraday precision ranged from 4.01 to 18.73 %, and interday precision varied from 4.83 to 20.00 %. Accuracy was examined through relative recoveries and ranged from 73.29 to 121.51 %. This method was successfully applied to analyze nine groundwater samples from monitoring wells of gas stations in São Paulo. Moreover, the greenness was assessed through AGREEprep metrics, and an overall score of 0.69 was obtained indicating that the method proposed can be considered sustainable.

Cannabidiol improves maternal obesity-induced behavioral, neuroinflammatory and neurochemical dysfunctions in the juvenile offspring.

Maternal obesity is associated with an increased risk of psychiatric disorders such as anxiety, depression, schizophrenia and autism spectrum disorder in the offspring. While numerous studies focus on preventive measures targeting the mothers, only a limited number provide practical approaches for addressing the damages once they are already established. We have recently demonstrated the interplay between maternal obesity and treatment with cannabidiol (CBD) on hypothalamic inflammation and metabolic disturbances, however, little is known about this relationship on behavioral manifestations and neurochemical imbalances in other brain regions. Therefore, here we tested whether CBD treatment could mitigate anxiety-like and social behavioral alterations, as well as neurochemical disruptions in both male and female offspring of obese dams. Female Wistar rats were fed a cafeteria diet for 12 weeks prior to mating, and during gestation and lactation. Offspring received CBD (50 mg/kg) from weaning for 3 weeks. Behavioral tests assessed anxiety-like manifestations and social behavior, while neuroinflammatory and neurochemical markers were evaluated in the prefrontal cortex (PFC) and hippocampus. CBD treatment attenuated maternal obesity-induced anxiety-like and social behavioral alterations, followed by rescuing effects on imbalanced neurotransmitter and endocannabinoid concentrations and altered expression of glial markers, CB1, oxytocin and dopamine receptors, with important differences between sexes. Overall, the findings of this study provide insight into the signaling pathways for the therapeutic benefits of CBD on neuroinflammation and neurochemical imbalances caused by perinatal maternal obesity in the PFC and the hippocampus, which translates into the behavioral manifestations, highlighting the sexual dimorphism encompassing both the transgenerational effect of obesity and the endocannabinoid system.

Effects on gene expression during maize-Azospirillum interaction in the presence of a plant-specific inhibitor of indole-3-acetic acid production.

Amongst the sustainable alternatives to increase maize production is the use of plant growth-promoting bacteria (PGPB). Azospirillum brasilense is one of the most well-known PGPB being able to fix nitrogen and produce phytohormones, especially indole-3-acetic acid - IAA. This work investigated if there is any contribution of the bacterium to the plant's IAA levels, and how it affects the plant. To inhibit plant IAA production, yucasin, an inhibitor of the TAM/YUC pathway, was applied. Plantlets' IAA concentration was evaluated through HPLC and dual RNA-Seq was used to analyze gene expression. Statistical differences between the group treated with yucasin and the other groups showed that A. brasilense inoculation was able to prevent the phenotype caused by yucasin concerning the number of lateral roots. Genes involved in the auxin and ABA response pathways, auxin efflux transport, and the cell cycle were regulated by the presence of the bacterium, yucasin, or both. Genes involved in the response to biotic/abiotic stress, plant disease resistance, and a D-type cellulose synthase changed their expression pattern among two sets of comparisons in which A. brasilense acted as treatment. The results suggest that A. brasilense interferes with the expression of many maize genes through an IAA-independent pathway.

An affordable and semiautomated approach as a novel strategy for the extraction of DNA using magnetic ionic liquids followed by real time-polymerase chain reaction.

This technical note describes a novel and straightforward experimental strategy for the extraction/capture of DNA using magnetic ionic liquid (MIL) followed by real time-polymerase chain reaction (qPCR) analysis. An affordable and low-cost magneto-based multiwell platform was first examined for capturing DNA allowing for simultaneous extractions that increased the analysis throughput of the experimental workflow. This configuration was composed of a series of neodymium rod magnets attached to a multiwell device in which a magneto-active extraction phase (MIL) was suspended for a single drop microextraction (SDME) approach. In this configuration, up to 32 extractions were able to be performed simultaneously, and DNA was successfully extracted from aqueous samples. Furthermore, as a proof-of-concept, this affordable and simple experimental strategy proved to be efficient for the extraction/capture of DNA from challenging samples such as whole blood without any pretreatment. This fact also consists of important feature compared to previous methodologies that required additional steps of sample preparation.

Development and validation of a dried plasma spot LC-MS/MS method for therapeutic monitoring of vancomycin and comparison with enzyme-multiplied immunoassay.

Vancomycin is used as an antimicrobial agent for the treatment of severe gram-positive infections. The importance of therapeutic monitoring of antimicrobials has led to the development of more specific sample preparation techniques capable of identifying with accuracy the concentration of this substance in the organism. An aliquot of 10 µl of plasma was transferred to Whatman 903 paper and dried at room temperature. The extraction method was performed by cutting and transferring the paper to a microtube and adding sodium phosphate buffer and internal standard. The mixture was shaken and centrifuged, and a 5-µl aliquot was injected into the analytical system. The optimization of the main parameters that can influence the extraction efficiency was performed using multivariate approaches to obtain the best conditions. The method developed was validated, providing coefficients of determination higher than 0.994 and a lower limit of quantification of 1 mg/L. Within- and between-run precision ranged from 11.4 to 17.30% and from 6.65 to 13.51%, respectively. This method was successfully applied to 75 samples of patients undergoing vancomycin therapy. The method was rapid, simple, and environmentally friendly with satisfactory analytical performance and was advantageous over the laborious and time-consuming methodologies used in therapeutic drug monitoring routine analyses.

High-throughput platforms for microextraction techniques.

The proposal of high-throughput platforms in microextraction-based approaches is important to offer sustainable and efficient tools in analytical chemistry. Particularly, automated configurations exhibit enormous potential because they provide accurate and precise results in addition to less analyst intervention. Recently, significant achievements have been obtained in proposing affordable platforms for microextraction techniques capable of being integrated with different analytical instrumentations. Considering the evolution of these approaches, this article describes innovative high-throughput platforms that have recently been proposed for the analysis of varied matrices, with special attention to laboratory-made devices. Additionally, some challenges, opportunities, and trends regarding these experimental workflows are pointed out.

Determination of hormones in urine by hollow fiber microporous membrane liquid-liquid extraction associated with 96-well plate system and HPLC-FLD detection.

In this work, hollow-fiber microporous membrane liquid-liquid extraction (HF-MMLLE) was associated with a 96-well plate system for the determination of estrone, 17-ß-estradiol, estriol and 17-α-ethinylestradiol in urine samples. This method exhibited some advantages, such as low cost, easy application, high-throughput and environmentally-friendly aspects. The type of organic solvent to fill the membrane, ionic strength effect, sample dilution, extraction and desorption time, and desorption solvent were examined. After the optimizations, the conditions were comprised of 45 min of extraction, 1-octanol as organic solvent and 15% (w/v) of NaCl; methanol was used as desorption solvent, and the desorption time was fixed at 10 min. The dilution of the sample increased the sensitivity due to the reduction of matrix effects; thus, urine samples were diluted 40-fold. The limits of detection ranged from 0.03 µg L-1 for 17-ß-estradiol to 15 µg L-1 for estrone, and the limits of quantification ranged from 0.1 µg L-1 for 17-ß-estradiol to 10 µg L-1 for estrone. The intra-day precision varied from 1.0% for estriol to 13.3% for 17-α-ethinylestradiol, and inter-day precision varied from 7.3% for estrone to 18.1% for estriol. The relative recoveries varied from 82 to 118%.

Nek1-inhibitor and temozolomide-loaded microfibers as a co-therapy strategy for glioblastoma treatment.

Malignant glioblastoma (GB) is the predominant primary brain tumour in adults, but despite the efforts towards novel therapies, the median survival of GB patients has not significantly improved in the last decades. Therefore, localised approaches that treat GB straight into the tumour site provide an alternative to enhance chemotherapy bioavailability and efficacy, reducing systemic toxicity. Likewise, the discovery of protein targets, such as the NIMA-related kinase 1 (Nek1), which was previously shown to be associated with temozolomide (TMZ) resistance in GB, has stimulated the clinical development of target therapy approaches to treat GB patients. In this study, we report an electrospun polyvinyl alcohol (PVA) microfiber (MF) brain-implant prepared for the controlled release of Nek1 protein inhibitor (iNek1) and TMZ or TMZ-loaded nanoparticles. The formulations revealed adequate stability and drug loading, which prolonged the drugs' release allowing a sustained exposure of the GB cells to the treatment and enhancing the drugs' therapeutic effects. TMZ-loaded MF provided the highest concentration of TMZ within the brain of tumour-bearing rats, and it was statistically significant when compared to TMZ via intraperitoneal (IP). All animals treated with either co-therapy formulation (TMZ + iNek1 MF or TMZ nanoparticles + iNek1 MF) survived until the endpoint (60 days), whereas the Blank MF (drug-unloaded), TMZ MF and TMZ IP-treated rats' median survival was found to be 16, 31 and 25 days, respectively. The tumour/brain area ratio of the rats implanted with either MF co-therapy was found to be reduced by 5-fold when compared to Blank MF-implanted rats. Taken together, our results strongly suggest that Nek1 is an important GB oncotarget and the inhibition of Nek1's activity significantly decreases GB cells' viability and tumour size when combined with TMZ treatment.

An overview of magnetic ionic liquids: From synthetic strategies to applications in microextraction techniques.

Remarkable progress has been achieved in the application of magnetic ionic liquids in microextraction-based procedures. These materials exhibit unique physicochemical properties of ionic liquids featuring additional responses to magnetic fields by incorporating a paramagnetic component within the chemical structure. This intriguing property can open new horizons in analytical extractions because the solvent manipulation is facilitated. Moreover, the tunable chemical structures of magnetic ionic liquids also allow for task-specific extractions that can significantly increase the method selectivity. This review aimed at providing an up-to-date overview of articles involving synthesis, physicochemical properties, and applications of magnetic ionic liquids highlighting recent developments and configurations. Moreover, a section containing critical evaluation and future trends in magnetic ionic liquid-based extractions is included.

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 promotes 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 is required for the control of these substances. This work exploited the development of an extraction method based on homogenous liquid-liquid microextraction with switchable hydrophilicity solvent (SHS) as extraction phase for the determination of the synthetic drugs 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine and N-methoxybenzyl-methoxyphenylethylamine derivates (25B, 25C and 25I) in postmortem blood, followed by liquid chromatography coupled to mass spectrometry in tandem. 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 was used as 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; limit of detection and limit of quantitation 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.

Mass spectrometry determination of seized oil-based anabolic-androgenic steroids products.

INTRODUCTION: The presence of anabolic-androgenic steroids (AAS) in illegal commercial products has been pointed as a global threat for public health. Due the correlation with adverse toxicological effects, there is a growing interest in the implementation of straightforward methods for the determination of AAS in seized products. This work exploited the development of a mass spectrometry approach to characterize the illegal oil formulations containing AAS. METHODS: The optimization of sample preparation was performed through a simplex-centroid design and the best condition was described as follow: an aliquot of 5 µL of sample were added with 995 µL of acetonitrile and water (75:25, v/v). The solution was vortexed and centrifuged. After that, 10 µL of supernatant were added with 35 µL of acetonitrile and water and internal standard (testosterone-d3, 1.25 ng). An aliquot of 5 µL was injected into the analytical system. RESULTS: The method developed was validated and successfully applied in 115 seized samples. Testosterone and its esters had the highest incidence, found in more than 50% of the samples. Besides that, drugs such as boldenone, methandienone, and trenbolone have also been found, where the low quality of the samples was evidenced by the wide variation in the concentration of the drugs, always quantified in sub-doses. Finally, at least one AAS was detected in each sample analyzed. The statistical results were grouped by principal components analysis, to better understand the profile of the seized samples. CONCLUSION: This work successfully established a fast and simple method for determination of AAS and can be applied to verify the profile of seized samples.

A proof-of-concept of parallel single-drop microextraction for the rapid and sensitive biomonitoring of pesticides in urine.

In this study, a lab-made parallel single-drop microextraction methodology using the magnetic ionic liquid trihexyltetradecylphosphonium tetrachloromanganate (II) as extraction solvent was developed to determine the pesticides tebuconazole, pendimethalin, dichlorodiphenyltrichloroethane, and dichlorodiphenyldichloroethylene in human urine samples. The experimental setup consisted of a 96-well plate system containing a set of magnetic pins that allowed for the manipulation of up to 96 samples simultaneously, providing an enhanced drop stability compared to traditional single-drop microextraction approaches. The optimal conditions employed 5.38 ± 0.55 mg of extraction solvent, 1.5 mL of diluted urine samples (1:10), extraction time of 130 min, and subsequent dilution in 20 µL of acetonitrile. The method exhibited satisfactory analytical performance, with limits of detection of 7.5 µg/L for all analytes and coefficients of determination higher than 0.9955. Intraday and interday precisions ranged from 3 to 17% (n = 3) and 15 to 18% (n = 9), respectively, with relative recovery of analytes ranging from 70 to 122%. The method proposed was successfully applied in two human urine samples and no sign of the analytes was detected. The results demonstrated that the proposed method allowed for cost-effective and high-throughput methodology to be explored as a valuable tool in bioanalytical applications.

Sustainable green solvents for microextraction techniques: Recent developments and applications.

The development and application of alternative green solvents in analytical techniques consist of trends in sample preparation, since this subject represents an important step toward sustainability in experimental procedures. This review is focused on the main theoretical aspects related to deep eutectic solvents (DES), switchable hydrophilicity solvents (SHS) and supramolecular solvents (SUPRAS). Recent applications are highlighted, particularly for the extraction of different analytes from environmental, biological and food matrices. Moreover, novel configurations are emphasized, aiming for efficient, automated and high-throughput procedures. This review also provides some critical points regarding the use of these solvents and their green aspects.

High-throughput approach for the in situ generation of magnetic ionic liquids in parallel-dispersive droplet extraction of organic micropollutants in aqueous environmental samples.

In this work, a novel and high-throughput parallel-dispersive droplet extraction (Pa-DDE) based on in situ formation of the hydrophobic MILs ([Co(C4IM)4+2]2[NTf2-], [Ni(C4IM)4+2]2[NTf2-] and [Ni(BeIM)4+2]2[NTf2-]) is demonstrated, for the first time, for the determination of benzophenone, metolachlor, triclocarban, pendimethalin, 4-methylbenzylidene camphor, and 2-ethylhexyl-4-methoxycinnamate from aqueous environmental samples. This experimental setup is comprised of a 96-well plate system containing a set of magnetic pins which were used to collect the MIL droplet after in situ formation. This consolidated system enabled simultaneous extraction of up to 96 samples and MIL production in one step. Using this apparatus, sample preparation times of 0.78 min per sample was achieved. The experimental conditions were carefully optimized using uni and multivariate approaches. The optimal conditions were comprised of sample volume of 1.25 mL, 4 mg of [Co(C4IM)4+2]2[Cl-] and 40 µL of LiNTf2 for the in situ formation, and dilution in 20 µL of acetonitrile. The analytical parameters of merit were successfully determined with LODs ranging from 7.5 to 25 µg L-1 and coefficients of determination higher than 0.989. Intraday and interday precision ranged from 6.4 to 20.6% (n = 3) and 11.6-22.9% (n = 9), respectively, with analyte relative recovery ranging between 53.9 and 129.1%.

Designing a green device to BAµE: Recycled cork pellet as extraction phase for the determination of parabens in river water samples.

This study reports a novel and environmentally friendly method based on bar adsorptive microextraction (BAµE) with cork pellet as extraction phase for the determination of methylparaben, ethylparaben, propylparaben and butylparaben in river water samples. This natural approach consists of a cork pellet recycled from wine stoppers used as biosorbent material to replace the traditional BAµE device. The analytical determinations were performed using a high-performance liquid chromatography-diode array detector (HPLC-DAD). Parameters such as type of desorption solvent, desorption and extraction time, sample pH and ionic strength were carefully optimized through univariate and multivariate approaches. Cork pellets of 15 mm length were inserted into vials containing 15 mL of water sample adjusted at pH 3 and 25% (w/v) of NaCl. The extraction step was carried out under agitation for 45 min followed by liquid desorption with 120 µL of methanol:acetonitrile (1:1 v/v) for 30 min. Satisfactory analytical performance was obtained with coefficients of determination ranging from 0.9921 for methylparaben to 0.9994 for propylparaben; intraday precision ranged from 6.7 to 18.3%, and interday precision varied from 7.2 to 20.0%. Accuracy was assessed through relative recovery assays and varied from 53 to 124%.

Determination of pesticides of different chemical classes in drinking water of the state of Santa Catarina (Brazil) using solid-phase microextraction coupled to chromatographic determinations.

The evaluation of the concentration of pesticides in drinking water presents a real concern. In this study, a simple and rapid method based on solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry and electron capture detectors was developed aiming at multiclass determination of 23 pesticides regulated by the Brazilian legislation. The extraction was carried out by direct immersion mode (DI-SPME) using DVB/Car/PDMS fiber coating. In order to improve the extraction efficiency, parameters such as temperature, salting-out effect, and extraction time were optimized. The method was evaluated using drinking water samples spiked with the analytes at different concentrations, and it showed good linearity in the range studied. The values obtained for limits of quantification (LOQ) were below the limits established by Brazilian regulations. Accuracy and precision of the method exhibited satisfactory results, providing relative recoveries from 70 to 123.34% at three spiked levels, and the relative standard deviations ranged from 0.53 to 24.8%. The method was applied in 20 drinking water samples from 13 cities in the State of Santa Catarina, Brazil.

A rapid analytical strategy for the determination of ayahuasca alkaloids in non-ritualistic approaches by UHPLC-MS/MS.

INTRODUCTION: Ayahuasca is a beverage composed by a mixture of herbs which contain the compound N,N-dimethyltriptamine (DMT) and the ß-carbolines. Although its use is legalized in Brazil only for religious and spiritual ceremonies, there is a growing black market specialized in the distribution of these compounds in form of herbal material through internet and mail. The purpose of this work was the development of an ultra-high-performance liquid chromatography-tandem mass spectrometry method for the determination of ayahuasca alkaloids and its application in seized ayahuasca products. METHODS: An aliquot of seized products was weighted and diluted with methanol. An aliquot of this solution was added with internal standard (DMT-d6), followed by injection in the analytical system. RESULTS: The limit of quantitation was 10ng/mL for DMT and 25ng/mL for harmine, harmaline and tetrahydroharmine. The concentration ranges used were 10-100ng/mL for DMT, harmine and harmaline and all analytes presented a coefficient of determination (r2)≥0,99. Analysis of four seized samples presented concentrations of DMT ranging between 31.5 and 46.5mg/g. Presence of ß-carbolines was not detected in the products. The variability of DMT concentrations can be correlated with the potential intoxications described in the literature. CONCLUSION: This work successfully established a determination method for ayahuasca alkaloids in herbal material. In addition, the workflow proved to be simple, rapid and useful to estimate the concentration of psychoactive compounds in seized materials, leading to further investigation of ayahuasca ritualistic or recreational exposure.

Expanding the applicability of magnetic ionic liquids for multiclass determination in biological matrices based on dispersive liquid-liquid microextraction and HPLC with diode array detector analysis.

Monitoring biological samples at trace levels of chemicals from anthropogenic actions such as pesticides, pharmaceuticals, and hormones has become a very important subject. This work describes a method for the determination of eight compounds of different chemical classes in human urine samples. Dispersive liquid-liquid microextraction based on magnetic ionic liquids was used as the sample preparation procedure. The main parameters of the method, such as sample dilution, type, and volume of disperser solvent, amount of magnetic ionic liquids, extraction time, and pH were optimized by univariate and multivariate procedures. Validation was performed using a urine sample of a male volunteer in order to obtain a calibration curve and the main analytical parameters of merit such as limits of detection and quantification. Values varied from 3.0 to 7.5 µg/L and from 10 to 25 µg/L, respectively. Satisfactory precisions of 21% for intraday (n = 3) and 16% for interday (n = 9) were achieved. Accuracy was evaluated by relative recovery assays using different urine samples and ranged from 75 to 130%. Robustness was assured by the Lenth method. The validated procedure was applied to five urine samples from different volunteers and the hormone estrone was found in one sample.

A straightforward and semiautomated membrane-based method as efficient tool for the determination of cocaine and its metabolites in urine samples using liquid chromatography coupled to quadrupole time-of-flight-mass spectrometry.

In this study, a novel and straightforward analytical methodology was proposed for the determination of cocaine (COC) and its main metabolites benzoylecgonine (BZE) cocaethylene (CE) and hydroxy­cocaine (COCOH) in urine samples. This approach consisted of a high-throughput and semiautomated configuration based on hollow-fiber renewal liquid membrane extraction (HFRLM) coupled to a 96-well plate system, which was proposed for the first time to analyze complex biological samples such as urine. The analytical determinations were performed using ultra-high performance liquid chromatography coupled to quadrupole time-of-flight-mass spectrometry (LC-ESI-QTOF-MS). The analytical methodology was fully optimized through Doehlert and simplex-centroid designs, and univariate approaches. Polypropylene membranes of 1 cm length were inserted in the pins of an extraction blade combined with a 96-well plate system and its pores were filled with hexane:dichloromethane:ethyl acetate (1:1:1 v/v/v) for 180 s; moreover, 20 µL of this mixture was added to the sample to allow for a renewable liquid membrane. The extraction step was carried out by keeping the blades immersed in vials containing 1.5 mL of diluted urine adjusted at pH 10 with 10% (w/v) of Na2CO3 during 20 min, followed by liquid desorption with 100 µL of acetonitrile. Finally, the extract was dried under N2 stream and resuspended with 20 µL of ultrapure water. Satisfactory analytical performance was obtained with coefficients of determination ranging from 0.9875 for BZE to 0.9986 for CE; intra-day precision ranged from 1.6 to 13.5%, and inter-day precision varied from 2.2 to 17.5%. Limits of detection ranged from 1.5 to 15.1 ng mL-1, and limits of quantification varied from 5 to 50 ng mL-1, with relative recoveries varied from 70.7 to 124.1%.

A green and low-cost method employing switchable hydrophilicity solvent for the simultaneous determination of antidepressants in human urine by gas chromatography - mass spectrometry detection.

In this study, the use of switchable hydrophilicity solvent with a simple and low-cost lab-made device for the extraction procedure in homogeneous liquid-liquid microextraction is proposed for the first time in the determination of antidepressants in human urine. The antidepressants studied consisted of fluoxetine, amitriptyline, nortriptyline, imipramine, desipramine and sertraline. The optimization of the main parameters that can influence on the extraction efficiency was performed through multivariate approaches. The analytes were separated and identified by gas chromatography coupled to mass spectrometry (GC-MS). The optimal extraction conditions consisted of using N,N-dimethylcyclohexylamine (DMCHA) as the switchable hydrophilicity solvent (SHS), 500 µL of urine sample previously diluted with ultrapure water at 1:1 ratio (v/v), 200 µL of a mixture of SHS:HCl 6 mol L-1 (1:1 v/v), 600 µL of NaOH 10 mol L-1 and 3 min of extraction time. A volume of 40 µL of diphenylamine at concentration of 500 µg L-1 (20 ng) was used as internal standard. The method developed was in-house validated, providing coefficients of determination higher than 0.995 for all analytes, limits of detection (LOD) from 0.02 to 0.88 µg L-1, limits of quantification (LOQ) from 0.05 to 2.92 µg L-1, relative recoveries of 68 to 102%, intra-day precision from 0.5 to 15.9%, inter-day precision from 4.2 to 19.3%, selectivity and robustness. The method proposed was successfully applied in five human urine samples from a Toxicological Information Center located in Porto Alegre (Brazil). The results demonstrated that the µP-SHS-HLLME approach is highly cost-effective, rapid, simple and environmentally-friendly with satisfactory analytical performance.