Sample Solvent Research Articles

New and Advanced Methods in Detection of Fruit Juice Adulteration: Focusing on Nano‐Biosensor

One of the most popular products made from fruit is juice, which is consumed as a snack by people of all ages due to its high content of polyphenols and vitamins. Therefore, the prevalence of adulteration in juices is very high, and ensuring the authenticity and quality of juices is a major concern for those responsible for monitoring food safety for the public. The most common frauds in fruit juices include adding water, sugar, organic acids, and other juices clouding agents and exceeding the permitted amount of sulfites. Having knowledge of the types of fraud in fruit juices and their detection methods is essential for developing more efficient detection methods. Chromatographic techniques, such as high‐performance liquid chromatography (HPLC) and gas chromatography (GC), are commonly used to determine the purity of fruit juices. Among the new methods for detecting counterfeit fruit juice, the development of bio‐nanosensors is particularly notable. These sensors reduce sample volume, analytical time, costs, and solvent consumption and will be discussed further in this study. Therefore, this review will explain the basic analytical approaches and chemometric tools used to assess the authenticity of fruit juice and identify any adulteration in the juice.

Development of a reliable method for determination of N-nitrosamines in medicines using disposable pipette extraction and HPLC-MS analysis.

This study outlines the development and optimization of an analytical method using Disposable Pipette Extraction (DPX) followed by high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis to determine NAs in medicines. HPLC-MS analysis utilized a reversed-phase and positive mode electrospray ion source. DPX parameters were optimized through univariate and multivariate analyses, including extraction phase, desorption solvent, sample pH, equilibrium time, and extraction/desorption cycles. The optimized conditions included a C18 extraction phase, methanol desorption solvent, pH at 7, an equilibrium time of 30 seconds, 2 extraction cycles, and 5 desorption cycles. Considering this method, it was possible to achieve a sample preparation step for the analysis of NAs in medicines using a minimal amount of extraction phase, sample, and desorption solvent. Furthermore, the total extraction procedure enables the extraction of NAs in around 4 minutes with NA recovery up to 98%. Analytical performance demonstrated precision and accuracy below 15% and a quantification limit of 1 ng mL-1, meeting validation requirements set by regulations worldwide. Thus, the DPX/HPLC-MS technique offers a faster and cost-effective method for analyzing NAs in medicines compared to traditional approaches. Besides, this method reduces solvent consumption and residue generation, enhancing environmental sustainability according to green chemistry principles.

Influence of selected operating conditions on starting spot width of test substance dissolved in solvent of high elution strength

The operational conditions for applying solutions of a dye (Oil Red) dissolved in acetone and methanol to a chromatographic plate are described. These solvents are characterized by high elution power, but they are very good solvents of various substances, so they are often used for this purpose in laboratory practice. However, their unfavorable feature, due to their use as solvents of samples placed on a chromatographic plate, is their high elution strength, which contributes to an increase of the diameter of the starting spot. To eliminate or reduce this unfavorable effect, this research used operational factors such as reduced speed of applying the test solution to the chromatographic plate, increased temperature (40 and 55 °C), and reduced pressure by 0.15 bar relative to atmospheric pressure. All this accelerated the evaporation of the solvents and led to smaller application spots. Studies have shown that the above-mentioned operational factors performed using equipment available in a regular laboratory contribute to a significant reduction of the starting spot despite the use of sample solvents with high elution strength.

Microfluidic Sampling of Undissolved Components from Subcellular Regions of Living Single Cells for Mass Spectrometry Analysis.

Precise sampling of undissolved chemical components from subcellular regions of living single cells is a prerequisite for their in-depth analysis, which could promote understanding of subtle early stage physiological or pathological processes. Here we report a microfluidic method to extract undissolved components from subcellular regions for MS analysis. The target single cell was isolated by the microchamber beneath the microfluidic probe and washed by the injected biocompatible isotonic glucose aqueous solution (IGAS). Then, the sampling solvent was injected to extract undissolved components from the expected subcellular region of the living single cell, where the position and size of the sampling region could be controlled. The components immobilized by undissolved cellular structures were proven to be successfully extracted. Since unextracted subcellular regions were protected by IGAS, the single cell could survive after a tiny part was extracted, providing the possibility of repetitive sampling of the same living cell. Phospholipids extracted from the subcellular regions were successfully identified. The results demonstrated the feasibility of our method for subcellular sampling and analysis.

Comprehensive UHPLC–MS screening methods for the analysis of triazolopyrazine precursor and its genotoxic nitroso-derivative in sitagliptin pharmaceutical formulation

A case study on Sitagliptin drug products and Sitagliptin/Metformin drug products concerning contamination with N-nitrosamines was performed using two newly developed analytical methods for determination of N-nitroso-triazolopyrazine (NTTP; 7-nitroso-3-(trifluoromethyl)–5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine) and its precursor triazolopyrazine (3-(trifluoromethyl)–5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine). The method for determination of triazolopyrazine was previously unpublished, the method for determination of NTTP was published only for analysis of active pharmaceutical ingredient Sitagliptin and not the drug forms. Solving the N-nitrosamine contamination is requested by regulatory authorities all over the world and thus is vital for all pharmaceutical companies. The solution always requires a sensitive analytical method. Both newly developed methods use liquid chromatography coupled with mass spectrometry (single quadrupole analyzer in case of triazolopyrazine and triple quadrupole analyzer in case of NTTP). Separation of triazolopyrazine was achieved on a column Acquity CSH C18 using a mobile phase consisting of aqueous ammonium formate buffered at pH 4.2 and acetonitrile. Detection was performed using positive electrospray and selected ion monitoring at m/z 193. Separation of NTTP was achieved on a column Acquity HSS T3 using a mobile phase consisting of 0.1 % formic acid in water and methanol. Detection was performed using positive electrospray and multiple reaction monitoring at transitions m/z 222.15→42.05 (collision energy 17 eV) and m/z 222.15→192.15 (collision energy 11 eV). Two issues specific to NTTP and triazolopyrazine previously not described in scientific literature were successfully troubleshooted. Spontaneous degradation of Sitagliptin to triazolopyrazine and methyl (R)–3-amino-4-(2,4,5-trifluorophenyl)butanoate was solved by using N,N-dimethylformamide as sample solvent during development of the method for quantitation of triazolopyrazine. A bad peak shape of NTTP due to the presence of rotamers of NTTP was successfully troubleshooted by increasing column temperature. Both methods were used during an optimization study of manufacturing of Sitagliptin and Sitagliptin/Metformin drug products. The goal of the study was to decrease NTTP content in the final drug product under the strict legislative limit set by Federal Drug Agency. The efficacy of several solutions was proven, but could not be fully disclosed due to Intellectual Property Protection policy of Zentiva. Instead, a brief review of recently published strategies to cope with N-nitrosamine contamination is presented.

Water layer and radiation damage effects on the orientation recovery of proteins in single-particle imaging at an X-ray free-electron laser

The noise caused by sample heterogeneity (including sample solvent) has been identified as one of the determinant factors for a successful X-ray single-particle imaging experiment. It influences both the radiation damage process that occurs during illumination as well as the scattering patterns captured by the detector. Here, we investigate the impact of water layer thickness and radiation damage on orientation recovery from diffraction patterns of the nitrogenase iron protein. Orientation recovery is a critical step for single-particle imaging. It enables to sort a set of diffraction patterns scattered by identical particles placed at unknown orientations and assemble them into a 3D reciprocal space volume. The recovery quality is characterized by a “disconcurrence” metric. Our results show that while a water layer mitigates protein damage, the noise generated by the scattering from it can introduce challenges for orientation recovery and is anticipated to cause problems in the phase retrieval process to extract the desired protein structure. Compared to these disadvantageous effects due to the thick water layer, the effects of radiation damage on the orientation recovery are relatively small. Therefore, minimizing the amount of residual sample solvent should be considered a crucial step in improving the fidelity and resolution of X-ray single-particle imaging experiments.

Micro-Injection Molding and Debinding Behavior of Hydroxyapatite/Zirconia Bi-Materials Fabricated by Two-Component Micro-Powder Injection Molding Process.

The micro-scale joining of two different materials using two-component micro-powder injection molding (2C-µPIM) is an intriguing technique. The formation of defects in bi-materials at different processing stages makes this technique challenging. This study presents the fabrication of defect-free bi-material micro-parts containing hydroxyapatite (HA) and 3 mol% yttria-stabilized zirconia (3YSZ) via 2C-µPIM. Critical powder volume concentrations (CPVCs) of 61.7 vol% and 47.1 vol% were obtained for the HA and 3YSZ powders, respectively. Based on the CPVCs, the optimal loadings for the HA and 3YSZ powders were selected as 60 vol% and 45 vol%, respectively. The HA and 3YSZ feedstocks were prepared by separately mixing the optimal powder contents with low-density polyethylene (LDPE) and palm stearin binders. The feedstocks displayed pseudoplastic behavior, and the lowest ranges of viscosity for the HA and 3YSZ at a temperature of 180 °C were 157.1-1392.5 Pa·s and 726.2-985.5 Pa·s, respectively. The feedstocks were injected to produce green HA/3YSZ micro-sized components. It was found that a solvent debinding temperature of 70 °C removed 60.6% of the palm stearin binder from the sample. In the thermal debinding stage, the open channels that formed in the bi-material sample's solvent debound at 70 °C and contributed to the removal of 93 to 95% of the binder system. When the debound bi-materials were sintered at 1300 °C, the highest relative density of 96.3% was obtained. The sintering operation revealed a linear shrinkage between 13 and 17% in the sintered HA/3YSZ micro-parts.

Application of Response Surface Method for Determination of Optimized Conditions for Quantification of 1,4-Dioxane in Model System of Polyethylene Glycol 200

The release of 1,4-dioxane probably contributes to the deterioration of marine habitats, animal health, and human liver and kidneys. The formulation of 1,4-dioxane in glycols, which has been applied for dehumidifying agents in refineries, may need to be replaced to ensure public health. Further, it is necessary to identify and precisely determine the levels of 1,4-dioxane in glycols for food quality control and environmental safety regulation. The objectives of this study were to validate a liquid–liquid extraction (LLE) method for 1,4-dioxane analysis and to optimize the LLE conditions using a response surface methodology (RSM). With consideration of the food matrix and its applications, polyethylene glycol 200 was used as the model system and analyzed by gas chromatography with flame ionization detection. In the experiments for the optimum extraction temperature and time of 1,4-dioxane in ultrasonic treatment, they were 20 °C and 10 min, respectively. The experimental conditions and results were analyzed by RSM with the Box–Behnken design, and the optimal extraction conditions for the LLE were determined to be coded with three independent variables (sample weight, solvent volume, and centrifugation speed). The amount of 1,4-dioxane increased as the amount of sample increased, whereas the amount of 1,4-dioxane decreased as the amount of solvent increased. This information can help to find the analytical methods for regulating the 1,4-dioxane content and its precise quantification in food products.

Optimisation of dispersive liquid-liquid microextraction for plasma sample preparation in bioanalysis of CDK4/6 inhibitors in therapeutic combinations for breast cancer treatment

Cyclin D dependent kinase 4 and 6 (CDK 4/6) inhibitors are novel anticancer drugs used in therapeutic combinations with endocrine therapy for breast cancer treatment. Their determination in patient plasma is of high interest as a prerequisite for possible therapeutic drug monitoring. Dispersive liquid-liquid microextraction (DLLME) shows great potential in bioanalytical sample preparation. Its simplicity and speed, along with the suitability for using small amounts of sample and hazardous solvents are some of its main advantages. However, its application on plasma samples is scarce and requires further development. The aim of this work was to explore the applicability of DLLME in the simultaneous extraction of six drugs of interest from human plasma, with an emphasis placed on achieving high extraction recoveries with low sample and solvent consumption. To tackle the low availability and amount of the plasma sample, as well as the complexity of the biological matrix, three novel DLLME modes are proposed: organic sample DLLME (OrS-DLLME), aqueous sample DLLME (AqS-DLLME), and a modified air-assisted DLLME (AA-DLLME). The extractant and disperser type and volume, volume ratios of all the components in the ternary system, effect of pH and salting out were optimised for all three proposed modes of DLLME. Optimised representative DLLME-HPLC-DAD-FLD method was validated and shown to be linear (R > 0.994), precise (RSD ≤13.8%, interday), accurate (bias −13.1–13.1%, interday) and robust (relative effect −3.34–6.08%). Simultaneous extraction of all six drugs with high recoveries (81.65–95.58%) was achieved. Sample volumes used were as low as 50–100 μL, with necessary organic solvent volumes in μL ranges. Greenness scores obtained using the AGREE software were between 0.63 and 0.66, demonstrating compliance with green analytical chemistry principles. Finally, the validated method was successfully applied on breast cancer patient plasma samples.

DETERMINATION OF RESIDUAL SOLVENTS IN PSMA 11 - AN ACTIVE PHARMACEUTICAL SUBSTANCE IN PSMA-11 KIT FOR Ga-68 LABELLING

A selective, sensitive and low sample consumption GC method for determination of residual solvents in PSMA samples was developed. Selectivity with respect to solvents such as ethanol, diethyl ether, 2-propanole, acetonitrile, dichloromethane, used in manufacturing of PSMA-11, was obtained on two different GC systems and columns. In all these cases, good separation and other system suitability parameters were obtained. The values of detection limit (LOD) and limit of quantitation (LOQ) were estimated and verified experimentally for ethanol, diethyl ether, 2-propanol (IPA), acetonitrile (ACN) and dichloromethane. Full validation parameters i.e.: selectivity, limit of detection (LOD), limit of quantitation (LOQ), linearity, precision, accuracy, robustness and system suitability parameters are presented with respect to ACN and IPA. Accuracy and precision were measured on two GC systems. Statistical tests exhibit, that there are no significant differences in accuracy and precision between two GC systems

Effervescence-assisted dispersive liquid-liquid microextraction for extraction and preconcentration of organochlorine pesticides in water samples

ABSTRACT. In this paper, effervescence-assisted dispersive liquid-liquid microextraction method has been developed for the extraction and preconcentration of organochlorine pesticides in water samples before their determination by gas chromatography-mass spectrometry. The method involves in-situ generation of CO2 bubbles to induce dispersion of the extraction solvent in the aqueous sample. Different parameters affecting the extraction efficiency of the method including the type and concentration of the effervescent agents as well as the type and volume of extraction solvent were optimized. Under optimum conditions, matrix matched calibration curves were constructed at eight concentrations ranging from 0.6–4.0 ng/mL showed good linearity with coefficient of determinations of ≥ 0.9961. The limits of detections and quantifications ranged from 0.2–0.4 and 0.6–1.0 ng/mL, respectively. The intra- and inter-day precisions studied at two concentration levels had below 5% relative standard deviation values. Similarly, recoveries investigated at two concentration levels ranged from 80.7–117.4%. The findings demonstrated that proposed method is simple, rapid, and efficient to be used as alternative method for analysis of organochlorine pesticides from environmental water and other similar matrices.
 
 KEY WORDS: Effervescence agents, CO2 bubbles, Organochlorine pesticides, Water samples, gas chromatography-mass spectroscopy
 
 Bull. Chem. Soc. Ethiop. 2023, 37(5), 1109-1122. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i5.4

On-line determination of the trace amount of cobalt(II) in real samples by flame atomic absorption spectrometry method after pre-concentration by modified polyvinyl chloride

This work reports a simple and sensitive on-line solid-phase extraction system for the pre-concentration and determination of a trace amount of Co(II (ions by flame atomic absorption spectrometry (FAAS). This method is based on the on-line retention of cobalt ions with polyvinyl chloride modified by 3-(2-thiazolylazo)-2,6-diaminopyridine in a mini-column system. The retained Co(II) ions were eluted with 1.0 mol L−1 HCl, and direct aspiration to flame atomic absorption spectrometry (FAAS) for an accurate determination of it. The important experimental parameters such as the solution pH, length of column (adsorbent mass), sample flow rate, solvent eluent, type and concentration of the eluent, and co-existing ion effects were investigated in detail and optimized. Under the optimum conditions, the calibration graph was linear over the concentration range of 2–150 µg L−1 for pre-concentration of 10.0 mL of the sample solution. The interassay precession (n = 6) was in the range of 1.8–5.2% at the concentration levels of 10.0, 50.0, 100.0, and 140.0 µg L−1. The limit of detection and enhancement factor were 1.3 µg L−1 and 40, respectively. The method was applied for determination of trace levels of Co(II) ions in different real samples such as tap water, waste water, vegetable, fruit, and drug with satisfactory results.

A simple and rapid extraction of lipids in plasma using spin column with superabsorbent polymer beads for mass spectrometry

The efficient extraction of lipid species in plasma was developed for quick sample preparation and accurate lipid analysis, using spin column with superabsorbent polymer beads (SAP), as the improvement of previous SAP method reported before. The modified SAP (mSAP) method is composed of simple steps, including sample loading, swelling, solvent addition, centrifugation, and drying of the resulting lipid solution. The mSAP method offers several advantages over the conventional and the previous SAP methods for lipid analysis in plasma sample. The mSAP method was approximately 10 times faster than the modified Folch protocol (Matyash method), methyl-tert-butyl ether based extraction method. The mSAP method offered an excellent recovery rate for most all major classes in the lipid standard mixture, outperforming the Matyash method. The limit of detection (LOD) of 1,2-diheptadecanoyl-sn-glycero-3-phophocholine (PC 17:0/17:0) spiking in plasma by the mSAP method is about seven times lower than those of the conventional methods. The relative standard deviation (RSD) values for inter- and intra-day variability of the mSAP method over a 5-day period were significantly lower than those of the previous SAP and Matyash methods. The mSAP method has been shown to be more time-saving, sensitive, reproducible and reliable, as evidence by its faster processing time, lower LOD, lower RSD values and high recovery rate for different lipid classes. Overall, these findings suggest that this method may be a promising approach for the application of total lipid analysis in lipidomic research in future.

Separation and recovery of titanium and scandium from the red mud

In this study, a full process in recovery of titanium and rare earth elements (REEs) from the red mud was developed. The suggested route consists of four main stages in the process flow diagram: sample preparation, leaching, hydrolysis, and solvent extraction. Sample preparation is proposed using a two-stage water washing followed by calcination to remove the acid-consuming components of the red mud. Dissolution of the Ti and REEs (with a focus on Sc) was developed using sulfuric acid followed by a hydrolysis process for the titanium precipitation. Concentration of the REEs in the solution was performed using a solvent extraction process. The dissolution efficiency of Ti and Sc were found 91 % and 93 %, respectively. Ti precipitation efficiency was about 86 %, and the final TiO2 product had a purity of 92 %, with the main impurities of a mixed iron and titanium oxide. After recovering Ti, Sc concentration using solvent extraction was studied. Using D2EHPA and alkaline stripping, Sc was concentrated from 69 ppm in the red mud to 1125 ppm in the obtained precipitate. The proposed process has the potential to be considered industrially due to its relative simplicity, high recovery yield, integrity, and utilization of low-cost reagents.

EXTRACTION OF BIOACTIVE COMPOUNDS FROM FENUGREEK LEAVES BY MACERATION WITH D-OPTIMAL DESIGN

In this study, optimum extraction conditions of bioactive compounds from fenugreek leaves (Trigonella-foenum graecum L.) were investigated using response surface methodology and the extracts having the highest total phenolic content, total flavonoid compounds, antioxidant activity and total saponin content were achieved. The independent process variables were solvent mixture ratio (water and ethanol, 0-100%), temperature (25-65°C) and sample–solvent ratio (10-50 g/L), and a constant extraction time of 120 minutes was used for all the design points. The experimental study was arranged according to D-optimal combined design and the process conditions were optimized using desirability function approach. Results showed that the extraction of phenolic compounds and antioxidant activity were increased at increasing water ratios and temperature and decreasing sample-solvent ratio. Saponins were extracted better when 25% ethanol was used as solvent. The optimum extraction conditions were determined as 100% of water, 49.71°C of temperature, and 10 g/L of sample–solvent ratio.

Solid Phase-Based Microextraction Techniques in Therapeutic Drug Monitoring.

Therapeutic drug monitoring is an established practice for a small group of drugs, particularly those presenting narrow therapeutic windows, for which there is a direct relationship between concentration and pharmacological effects at the site of action. Drug concentrations in biological fluids are used, in addition to other clinical observation measures, to assess the patient's status, since they are the support for therapy individualization and allow assessing adherence to therapy. Monitoring these drug classes is of great importance, as it minimizes the risk of medical interactions, as well as toxic effects. In addition, the quantification of these drugs through routine toxicological tests and the development of new monitoring methodologies are extremely relevant for public health and for the well-being of the patient, and it has implications in clinical and forensic situations. In this sense, the use of new extraction procedures that employ smaller volumes of sample and organic solvents, therefore considered miniaturized and green techniques, is of great interest in this field. From these, the use of fabric-phase extractions seems appealing. Noteworthy is the fact that SPME, which was the first of these miniaturized approaches to be used in the early '90s, is still the most used solventless procedure, providing solid and sound results. The main goal of this paper is to perform a critical review of sample preparation techniques based on solid-phase microextraction for drug detection in therapeutic monitoring situations.

Bioinertization of NanoLC/MS/MS Systems by Depleting Metal Ions From the Mobile Phases for Phosphoproteomics

We have successfully developed a bioinertized nanoflow LC/MS/MS (nanoLC/MS/MS) system for the highly sensitive analysis of phosphopeptides by depleting metal ions from the mobile phase. We found that not only direct contact of phosphopeptides with metal components, but also indirect contact with nanoLC pumps through the mobile phase causes significant losses during the recovery of phosphopeptides. Moreover, electrospray ionization was adversely affected by the mobile phase containing multiple metal ions as well as by the sample solvents contaminated with metal ions used in immobilized metal ion affinity chromatography for phosphopeptide enrichment. To solve these problems, metal ions were depleted by inserting an online metal ion removal device containing metal-chelating membranes between the gradient mixer and the autosampler. As a result, the peak areas of the identified phosphopeptides increased an average of 9.9-fold overall and 77-fold for multiply phosphorylated peptides with the insertion of the online metal ion removal system. This strategy would be applicable to the highly sensitive analysis of other phosphorylated biomolecules by microscale-LC/MS/MS.

Extraction of phenolic and flavonoids compounds from kenaf (Hibiscus Cannabinus L.) using ultrasound assisted extraction

The objective of this research is to conduct the preliminary phytochemical screening of phenolic and flavonoid compounds from leaves and bast fibres of Hibiscus Cannabinus L that been extracted using Ultrasound Assisted Extraction (UAE). This study was conducted to evaluate the comparative phytochemical screening test of kenaf leaves and kenaf bast fibres using Ultrasound Assisted Extraction (UAE) with water and absolute ethanol as extraction solvent and different extraction times. Phytochemical screening was carried out with the crude extracts by tested with ferric chloride test for phenolic compounds meanwhile sodium hydroxide 10% test for flavonoid compounds. The major finding of this research is the presences of phenolic and flavonoid compounds by the colour changes using the phytochemical screening test. In phenolic compound test, bast fibres shown the orange colour for ethanol solvents while for water shows dark orange with precipitate. Meanwhile, leaves give dark green colours for water and for ethanol the dark green colour was more intense. In flavonoid compound test, both water and ethanol solvent for bast fibres samples shows pale yellow while leaves show yellow for water and bright yellow for ethanol. Overall, the presence of phenolic and flavonoid compounds was confirmed in Hibiscus Cannabinus L. The result shown the kenaf leaves gives the most positives presences of both compounds according by the colour changes in water and ethanol solvents. The extracts from locally grown kenaf shows the presences of phenolic and flavonoid compounds which can be used as antibiotics for diseases.

About Analytical and Technological Reasons of Out-of-Specification Results for Assay and Disolution Tests (Review)

Introduction. Out of specification (OOS) results represent a major challenge in the development, validation and use of the Assay and Dissolution methods. The topic is relevant, which is confirmed by Internet search data for the phrase "Out-of-Specification" + "HPLC" – about 35,300 results were found.Text. The analytical and technological reasons (factors) that can lead to underestimated or overestimated test results are considered and systematized in the form of a summary table important for practice. These are the following factors. Factors associated with the calculation formula. Factors related to the preparation of samples. Factors related to the sample solvent and ratio of the pH the sample solution and the mobile phase. Factors associated with chromatograms and their processing. The main technological factors.Conclusion. Data and recommendations are presented to search for analytical and technological reasons for obtaining Out-of-Specification results in the case of tests Assay and Dissolution.

Comparison of the Determination of Some Antihypertensive Drugs in Clinical Human Plasma Samples by Solvent Front Position Extraction and Precipitation Modes.

The determination of the selected antihypertensive drugs in human plasma samples with the novel solvent front position extraction (SFPE) technique is presented. The SFPE procedure combined with LC-MS/MS analysis was used for the first time to prepare a clinical sample containing the drugs mentioned above from different therapeutic groups. The effectiveness of our approach was compared with the precipitation method. The latter technique is usually used to prepare biological samples in routine laboratories. During the experiments, the substances of interest and the internal standard were separated from other matrix components using a prototype horizontal chamber for thin-layer chromatography/high-performance thin-layer chromatography (TLC/HPTLC) with a moving pipette powered by a 3D mechanism, which distributed the solvent on the adsorbent layer. Detection of the six antihypertensive drugs was performed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode. Results obtained by SFPE were very satisfactory (linearity R2 ≥ 0.981; %RSD ≤ 6%; LOD and LOQ were in the range of 0.06-9.78 ng/mL and 0.17-29.64 ng/mL, respectively). The recovery was in the range of 79.88-120.36%. Intra-day and inter-day precision had a percentage coefficient of variation (CV) in the range of 1.10-9.74%. The procedure is simple and highly effective. It includes the automation of TLC chromatogram development, which significantly reduced the number of manual operations performed, the time of sample preparation and solvent consumption.