Exploring dried blood spot sampling technique for simultaneous quantification of antiretrovirals: lamivudine, stavudine and nevirapine in a rodent pharmacokinetic study

A high‐performance liquid chromatography/positive ion electrospray tandem mass spectrometry method for the simultaneous quantification of lamivudine, stavudine and nevirapine was developed and validated in dried blood spot (DBS) cards. The analytes were separated using an isocratic mobile phase on a reverse phase column and analyzed by MS/MS in the MRM mode using the respective [M + H]⁺ ions, m/z 230–112 for lamivudine, m/z 225–127 for stavudine, m/z 267–226 for nevirapine, m/z 383–337 for zidovudine (IS). The lower limit of quantification was 1 ng/mL for both lamivudine and stavudine and 10 ng/mL for nevirapine. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The method was successfully applied to quantify them in a rat pharmacokinetic study in whole blood, plasma and DBS cards after a single oral co‐administration at the dose of 10, 2 and 13 mg/kg for lamivudine, stavudine and nevirapine, respectively, to male Wistar rats. Following oral administration the pharmacokinetic results in all the matrices are in close agreement. Thus accomplishment of this method would facilitate the ease of collection of clinical samples on DBS cards for lamivudine, stavudine and nevirapine during human clinical trials and therapeutic drug monitoring. Copyright © 2012 John Wiley & Sons, Ltd.     

Simultaneous determination of seven nitrogen‐containing phenyl ethers in cosmetics by gas chromatography with mass spectrometry and dispersive solid‐phase extraction

An analytical method was established for the simultaneous determination of seven nitrogen‐containing phenyl ethers (2‐anisidine, 3‐anisidine, 4‐anisidine, 2‐nitroanisole, 3‐nitroanisole, 4‐nitroanisole, and 3,3'‐dimethoxybenzidine) in cosmetics by gas chromatography with mass spectrometry in this work. The samples were extracted with ethyl acetate and purified with primary secondary amine during the dispersed solid‐phase extraction. The analytes were separated by a DB‐17MS column and detected in the electron ionization mode of mass spectrometry in the selected ions monitoring mode. The extraction solvent, purification adsorbents, and chromatographic column behavior were optimized. The results indicated that the seven analytes show good linear relationship (R ² > 0.9965) in the concentrations of 5.0–5000 μg/L. The quantitation limits of the method ranged from 19.0 to 84.8 μg/kg. The recovery rates of seven analytes were in the range of 72.6–114% with the relative standard deviations of 1.1–7.5%. Real sample analyses showed that this accurate and precise method could be appropriate for simultaneous determination of seven nitrogen‐containing phenyl ethers in cosmetics.     

Sensitive quantification of clozapine and its main metabolites norclozapine and clozapine-<Emphasis Type="Italic">N</Emphasis>-oxide in serum and urine using LC-MS/MS after simple liquid–liquid extraction work-up

An LC-MS/MS method for the determination of the atypic neuroleptic clozapine and its two main metabolites norclozapine and clozapine-N-oxide has been developed and validated for serum and urine. After addition of d4-clozapine as deuterated internal standard a fast single-step liquid–liquid extraction under alkaline conditions and with ethyl acetate as organic solvent followed. The analytes were chromatographically separated on a Synergi Polar RP column using gradient elution with 1 mM ammonium formate and methanol. Data acquisition was performed on a QTrap 2000 tandem mass spectrometer in multiple reaction monitoring mode with positive electrospray ionization. Two transitions were monitored for each analyte in order to fulfill the established identification criteria. The validation included the determination of the limits of quantification (1.0 ng/mL for all analytes in serum and 2.0 ng/mL for all analytes in urine), assessment of matrix effects (77% to 92% in serum, 21 to 78% in urine) and the determination of extraction efficiencies (52% to 85% for serum, 59% to 88% for urine) and accuracy data. Imprecision was <10%, only the quantification of norclozapine in urine yielded higher relative standard deviations (11.2% and 15.7%). Bias values were below ±10%. Dilution of samples had no impact on the correctness for clozapine and norclozapine in both matrices and for clozapine-N-oxide in serum. For quantification of clozapine-N-oxide in urine a calibration with diluted calibrators has to be used. Calibration curves were measured from the LOQ up to 2,000 ng/mL and proved to be linear over the whole range with regression coefficients higher than 0.98. The method was finally applied to several clinical serum and urine samples and a cerebro-spinal fluid sample of an intoxicated 13-month-old girl.     

Bare polyprolylene hollow fiber as extractive phase for in‐tube solid‐phase microextraction to determine estrogens in water samples

Polypropylene hollow fibers as the adsorbent were directly filled into a polyetheretherketone tube for in‐tube solid‐phase microextraction. The surface properties of hollow fibers were characterized by a scanning electron microscope. Combined with high performance liquid chromatography, the extraction tube showed good extraction performance for five environmental estrogen hormones. To achieve high analytical sensitivity, four important factors containing sampling volume, sampling rate, content of organic solvent in sample, and desorption time were investigated. Under the optimum conditions, an online analysis method was established with wide linear range (0.03–20 µg/L), good correlation coefficients (≥0.9998), low limits of detection (0.01–0.05 µg/L), low limits of quantitation (0.03–0.16 µg/L), and high enrichment factors (1087–2738). Relative standard deviations (n = 3) for intraday (≤3.6%) and interday (≤5.1%) tests proved the stable extraction performance of the material. Durability and chemical stability of the extraction tube were also investigated, relative standard deviations of all analytes were less than 5.8% (n = 3), demonstrating the satisfactory stability. Finally, the method was successfully applied to detect estrogens in real samples.     

Analyte focusing by micelle collapse for liquid extraction surface analysis coupled with capillary electrophoresis of neutral analytes on a solid surface

Liquid extraction surface analysis (LESA) has an advantage of directly sampling analytes on a surface, thus avoiding unnecessary dilution by homogenization of the bulk sample commonly practiced in solid sample analysis. By combining LESA with CE, the additional advantage of separating analytes before detection can be accomplished. For neutral molecules, MEKC needs to be used. Since the detection sensitivity of CE in general suffers from the small capillary dimension, analyte focusing by micelle collapse was employed for enhanced extraction in LESA and sample preconcentration for MEKC. In addition, using a commercial CE instrument, the LESA process was performed much faster and more reliably compared to our first demonstration of LESA‐CE using a homemade CE setup. Three neutral water‐insoluble pesticides sprayed on an apple skin were directly extracted, preconcentrated, and analyzed by the automated LESA‐analyte focusing by micelle collapse‐MEKC with high sensitivity in 10 min. The relative standard deviations of the migration times and peak heights were 0.8–2.1 and 1.2–3.0%, respectively when ametryn was used as an internal standard. The limits of detection obtained with UV absorbance at 200 nm were 1.8–6.4 ppb.     

Simultaneous determination of eight alkaloids and oleandrin in herbal cosmetics by dispersive solid‐phase extraction coupled with ultra high performance liquid chromatography and tandem mass spectrometry

We utilized ultra‐high performance liquid chromatography with tandem mass spectrometry and dispersive solid‐phase extraction to develop a new method for the detection of nine analytes (scopolamine, cephaeline, strychnine, hyoscyamine, brucine, hydrastine, ajmalicine, colchicine, and oleandrin) in herbal cosmetics. Acetonitrile/water and 2‐propylaminoethylamine were used to disperse and purify during the dispersive solid‐phase extraction step. The analytes were separated by a Waters UPLC HSS T3 column and detected through electrospray ionization source in the positive mode with multi‐reaction monitoring conditions. Under the optimal conditions, the calibration curves were linear in the range of 0.2–100.0 μg/L with the correlation coefficients higher than 0.995. The method limit of quantitation (S/N = 10) were 5.0 μg/kg for oleandrin and 1.0 μg/kg for the other eight alkaloids. The mean recoveries at three spiked concentration levels of 1.0–10.0 μg/kg were in the range of 86.9–116.5% with the intra‐day relative standard deviations (n  = 6) ranging from 2.4 to 8.8%, and inter‐day relative standard deviations ranging from 2.7 to 5.7%. This method is accurate, simple and rapid, and has been applied to the quality supervision of herbal cosmetics in Guangzhou.     

Dispersive liquid–liquid microextraction followed by gas chromatography–mass spectrometry for the rapid and sensitive determination of UV filters in environmental water samples

The performance of the dispersive liquid–liquid microextraction (DLLME) technique for the determination of eight UV filters and a structurally related personal care species, benzyl salicylate (BzS), in environmental water samples is evaluated. After extraction, analytes were determined by gas chromatography combined with mass spectrometry detection (GC-MS). Parameters potentially affecting the performance of the sample preparation method (sample pH, ionic strength, type and volume of dispersant and extractant solvents) were systematically investigated using both multi- and univariant optimization strategies. Under final working conditions, analytes were extracted from 10 mL water samples by addition of 1 mL of acetone (dispersant) containing 60 μL of chlorobenzene (extractant), without modifying either the pH or the ionic strength of the sample. Limits of quantification (LOQs) between 2 and 14 ng L⁻¹, inter-day variability (evaluated with relative standard deviations, RSDs) from 9% to 14% and good linearity up to concentrations of 10,000 ng L⁻¹ were obtained. Moreover, the efficiency of the extraction was scarcely affected by the type of water sample. With the only exception of 2-ethylhexyl-p-dimethylaminobenzoate (EHPABA), compounds were found in environmental water samples at concentrations between 6 ± 1 ng L⁻¹ and 26 ± 2 ng mL⁻¹.     

Improved in‐tube electro‐membrane extraction followed by high‐performance liquid chromatography for simple and selective determination of ionic compounds: Optimization by central composite design

In this work, an efficient sample clean‐up method, named in‐tube electro‐membrane extraction, is modified to resolve the formation of bubbles in the extraction process. This modified method is applied for the extraction of two model analytes including tartrazine and sunset yellow from food samples. The method is based on the electro‐kinetic migration of ionized compounds by the application of an electrical potential difference, and on this basis the analytes under investigation, as anionic compounds, simply migrate from the donor phase and concentrate in the acceptor phase. A thin polypropylene sheet placed in the tube acts as a support for the membrane solvent, and it separates 30 μL of the aqueous acceptor from 1.2 mL of the aqueous donor. This setup can be used to solve the problem of extracting highly hydrophilic analytes. Response surface methodology is used for optimization of the experimental parameters so that under the optimized conditions, the method provides a good linearity in the range of 50–1000 ng/mL, low limits of detection (15–25 ng/mL), good extraction repeatabilities (relative standard deviations below 8.1%, n  = 5), and high extraction recoveries (54–76%).     

Fabrication of boron‐rich multiple monolithic fibers for the solid‐phase microextraction of carbamate pesticide residues in complex samples

To enrich carbamate pesticides from complex matrices, an adsorbent based on poly (vinylboronic anhydride pyridine complex‐co‐ethylenedimethacrylate) monolith was fabricated and utilized as the extraction phase of multiple monolithic fiber solid‐phase microextraction. Due to the abundant boron atoms in the monolith, the B–N coordination interaction between adsorbent and analytes play a key role in the efficient extraction of analytes. Under the optimized conditions, the monolithic fibers were combined with high‐performance liquid chromatography for the quantify trace levels of carbamate pesticides in environmental water and orange juice samples. For water sample, the limit of detection and limit of quantification were in the range of 0.017–0.29 and 0.057–0.96 μg/L, respectively. The related values in orange juice samples were 0.038–0.39 and 0.12–1.36 μg/kg, respectively. Besides, the proposed method also exhibits wide linearity, satisfactory coefficients of determination, and good precision. The introduced approach was successfully applied to determine trace target analytes in real‐life samples. The spiked recoveries with different fortified concentrations were in the range of 80.4–117% for water samples and 83.7–119% for fruit juice samples. The relative standard deviations were below 10%. The results evidence that the suggested method was convenient, reliable, and eco‐friendly for the monitoring of trace levels of carbamate pesticides in complex samples such as waters and juices.     

Simultaneous quantification of curdione,furanodiene and germacrone in rabbit plasma using liquid chromatography–tandem mass spectrometry and its application to a pharmacokinetic study

A simple, rapid and sensitive method was developed for the simultaneous quantification of curdione, furanodiene and germacrone in rabbit plasma using a LC‐MS/MS analysis. The plasma sample preparation was a simple deproteinization by the addition of 3 vols of acetonitrile followed by centrifugation. The analytes and internal standard (IS) costunolide were separated on a Zorbax SB‐C₁₈ column (3.5 µm, 2.1 × 100 mm) with mobile phase of methanol–water (90:10, v/v) containing 0.1% formic acid at a flow rate of 0.3 mL/min with an operating temperature of 25°C. Detection was carried out by atmospheric pressure chemical ionization in positive ion selected reaction monitoring mode. Linear detection responses were obtained for the three test compounds ranging from 5 to 5000 ng/mL and the lower limits of quantitation were 5‐10ng/mL. The intra‐ and inter‐day precisions (relative standard deviations) were within 9.4% for all analytes, while the deviation of assay accuracies was within ±10.0%. The average recoveries of analytes were >80.0%. All analytes were proved to be stable during all sample storage, preparation and analytical procedures. The method was successfully applied to the pharmacokinetic study of the three compounds after vaginal drug delivery of Baofukang suppository to rabbit. Copyright © 2015 John Wiley & Sons, Ltd.     

Polypyrrole‐magnetite dispersive micro‐solid‐phase extraction combined with ultraviolet‐visible spectrophotometry for the determination of rhodamine 6G and crystal violet in textile wastewater

Polypyrrole‐magnetite dispersive micro‐solid‐phase extraction method combined with ultraviolet‐visible spectrophotometry was developed for the determination of selected cationic dyes in textile wastewater. Polypyrrole‐magnetite was used as adsorbent due to its thermal stability, magnetic properties, and ability to adsorb Rhodamine 6G and crystal violet. Dispersive micro‐solid‐phase extraction parameters were optimized, including sample pH, adsorbent amount, extraction time, and desorption solvent. The optimum polypyrrole‐magnetite dispersive micro‐solid phase‐extraction conditions were sample pH 8, 60 mg polypyrrole‐magnetite adsorbent, 5 min of extraction time, and acetonitrile as the desorption solvent. Under the optimized conditions, the polypyrrole‐magnetite dispersive micro‐solid‐phase extraction with ultraviolet‐visible method showed good linearity in the range of 0.05–7 mg/L (R ² > 0.9980). The method also showed a good limit of detection for the dyes (0.05 mg/L) and good analyte recoveries (97.4–111.3%) with relative standard deviations < 10%. The method was successfully applied to the analysis of dyes in textile wastewater samples where the concentration found was 1.03 mg (RSD ±7.9%) and 1.13 mg/L (RSD ± 4.6%) for Rhodamine 6G and crystal violet, respectively. It can be concluded that this method can be adopted for the rapid extraction and determination of dyes at trace concentration levels.     

Liquid chromatography mass spectrometry for the determination of salvianolic acid B,a natural compound from the herb Danshen in rat plasma and application to pharmacokinetic study

A sensitive and specific liquid chromatographic–electrospray ionization mass spectrometric method was developed for quantification of salvianolic acid B in rat plasma with resveratrol as the internal standard. The analytes were separated on a reversed‐phase column with acetonitrile (40%) and water (60%) containing 0.75% formic acid as mobile phase at a flow rate of 1 mL/min. Liquid–liquid extraction was adopted for the sample preparation, and the analytes were determined using electrospray negative ionization mass spectrometry in the selective monitoring mode. The method was validated over the concentration range 0.1–40 µg/mL using 0.1 mL of plasma with coefficients of correlation >0.999. The intra‐ and inter‐day precisions of analysis were <10%, and accuracy ranged from 94 to 101%. This method was successfully applied to a pharmacokinetics of salvianolic acid B in rats. Copyright © 2009 John Wiley & Sons, Ltd.     

Simple magnetization of Fe3O4/MIL‐53(Al)‐NH2 for a rapid vortex‐assisted dispersive magnetic solid‐phase extraction of phenol residues in water samples

The present work describes a simple route to magnetize MIL‐53(Al)‐NH₂ sorbent for rapid extraction of phenol residues from environmental samples. To extend the applications and performances of the metal‐organic frameworks in the field of adsorption materials, we combined the properties of metal‐organic frameworks and magnetite to decrease the extraction time and simplify the extraction process as well. In this study, a simple and quick vortex‐assisted dispersive magnetic solid phase extraction method for the extraction of ten United States Environmental Protection Agency's priority phenols from water samples prior to analysis by high‐performance liquid chromatography with photodiode array detection was proposed. The developed method exhibits a rapid enrichment of the target analytes within 10 s for extraction and 10 s for desorption. Low detection limits of 1.8‐41.7 µg/L and quantitation limits of 6.0‐139.0 µg/L with the relative standard deviations for intra‐ and interday analyses less than 12% were achieved. Satisfactory recoveries in the range of 80‐111% with the relative standard deviations less than 11% demonstrated that Fe₃O₄/MIL‐53(Al)‐NH₂ is promising sorbent in the field of magnetic solid‐phase extraction for environmental samples.     

Determining multi‐pesticide residues in teas by dispersive solid‐phase extraction combined with speed‐regulated directly suspended droplet microextraction followed by gas chromatography–tandem mass spectrometry

In this study, an effective speed‐regulated directly suspended droplet microextraction method was developed to condense pesticide residues from teas through dispersive solid‐phase extraction prior to analysis by gas chromatography with tandem mass spectrometry. The extractant was intentionally dispersed into the sample solution in the form of globules through high‐speed agitation. This procedure increases the contact area between the binary phases and shortens the distribution equilibrium time. The fine globules reassembled by decelerating stirring speed, the extractant could be taken out for gas chromatography with tandem mass spectrometry. Recovery studies were performed under optimized extraction conditions by using matrix blanks fortified with pesticides at three concentrations (10, 50, and 100 µg/kg). Over 87% of the recoveries for the analytes in four tea matrices were acceptable given their recovery ranges of 70–120% and relative standard deviations of ≤20%. The limits of quantification of most pesticides were lower than 10 µg/kg and thus satisfied the requirements for maximum residue levels prescribed by the European Community. A total of 38 tea samples from local markets were analyzed by using the proposed method. Results showed that chlorpyrifos was the most frequently detected pesticide in teas. The method is a potential choice for the routine monitoring of pesticide residues in complex matrices.     

Phytic acid induced three‐dimensional graphene for the enrichment of phthalate esters from bottled water and sports beverage samples

A three‐dimensional graphene was synthesized through a hydrothermal reaction of graphene oxide with phytic acid. The microstructure and morphology of the phytic acid induced three‐dimensional graphene were investigated by nitrogen adsorption–desorption isotherms, scanning electron microscopy, and transmission electron microscopy. With a large surface area and three‐dimensional structure, the graphene was used as the solid‐phase extraction adsorbent for the extraction of phthalate esters from bottled water and sports beverage samples before high‐performance liquid chromatographic analysis. The results indicated that the graphene was efficient for the solid‐phase extraction of phthalate esters. The limits of detection (S/N = 3) of the method for the analytes were 0.02–0.03 ng/mL for the water samples and 0.03–0.15 ng/mL for the sports beverage sample. The limits of quantitation (S/N = 9) for the analytes were 0.06–0.09 ng/mL for water samples and 0.09–0.45 ng/mL for sports beverage sample. The calibration curves for the phthalate esters by the method had a good linearity from 0.1 to 80.0 ng/mL with correlation coefficients larger than 0.9997. The recoveries of the analytes for the method fell in the range of 86.7–116.2% with the relative standard deviations between 1.5 and 6.8%.     

Determination of parabens in wastewater samples via robot-assisted dynamic single-drop microextraction and liquid chromatography–tandem mass spectrometry

Dynamic single-drop microextraction (SDME) was automatized employing an Arduino-based lab-made Cartesian robot and implemented to determine parabens in wastewater samples in combination with liquid chromatography–tandem mass spectrometry. A dedicated Arduino sketch controls the auto-performance of all the stages of the SDME process, including syringe filling, drop exposition, solvent recycling, and extract collection. Univariate and multivariate experiments investigated the main variables affecting the SDME performance, including robot-dependent and additional operational parameters. Under selected conditions, limit of detections were established at 0.3 µg/L for all the analytes, and the method provided linear responses in the range between 0.6 and 10 µg/L, with adequate reproducibility, measured as intraday relative standard deviations (RSDs) between 5.54% and 17.94%, (n = 6), and inter-days RSDs between 8.97% and 16.49% (n = 9). The robot-assisted technique eased the control of dynamic SDME, making the process more feasible, robust, and reliable so that the developed setup demonstrated to be a competitive strategy for the automated extraction of organic pollutants from water samples.     

Ballpoint connector‐protected salt‐oil‐salt liquid phase microextraction for concentration and enrichment of trace anthraquinone compounds in rhubarb

This study proposed a new ballpoint connector‐protected salt‐oil‐salt liquid phase microextraction for extraction and enrichment of trace rhein and chrysophanol in rhubarb prior to determination of the analytes by high performance liquid chromatography. In this study, a handy ballpoint connector (between ballpoint tip and ink chamber) was used as extraction device, in which its cavity was filled with n‐octanol, and the bare n‐octanol in its two opening ends was covered with a thin layer of sodium chloride film. The design subtly assembled salt film onto ballpoint connector for extraction and enrichment, which greatly improved the enrichment factors of the target analytes. Moreover, the novel procedure and its extraction mechanism were described and analyzed, and several crucial parameters reflecting the extraction effect were investigated and optimized. Under optimum conditions, high enrichment factors (247 and 127), good linearities with r ≥ 0.9998, limits of detection (0.6–1.1 ng/mL), relative standard deviations of intra‐ and interday (2.2–8.8% and 4.3–8.9%), and average recoveries (97.6–98.1%), were obtained, respectively. The proposed method can not only eliminate the negative effects from viscosity and ion strength at high salt concentration of sample phase, but also make salting‐out effect be focused on small area so as to maximize the extraction effect.     

Validation of a two-dimensional gas chromatography mass spectrometry method for the simultaneous quantification of cannabidiol, Δ9-tetrahydrocannabinol (THC), 11-hydroxy-THC, and 11-nor-9-carboxy-THC in plasma

A sensitive analytical method for simultaneous quantification of sub-nanogram concentrations of cannabidiol (CBD), Δ⁹-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH) in plasma is presented for monitoring cannabinoid pharmacotherapy and illicit cannabis use. Analytes were extracted from 1 mL plasma by solid-phase extraction, derivatized with N,O-bis(trimethylsilyl) trifluoroacetamide with 1% trimethylchlorosilane, and analyzed by two-dimensional gas chromatography mass spectrometry (2D-GCMS) with cryofocusing. The lower calibration curve was linear from 0.25–25 ng/mL for CBD and THC, 0.125-25 ng/mL for 11-OH-THC and 0.25-50 ng/mL for THCCOOH. A second higher linear range from 5–100 ng/mL, achieved through modification of injection parameters, was validated for THC, 11-OH-THC, and THCCOOH and was only implemented if concentrations exceeded the lower curve upper limit of linearity. This procedure prevented laborious re-extraction by allowing the same specimen to be re-injected for quantification on the high calibration curve. Intra- and inter-assay imprecision, determined at four quality control concentrations, were ≤7.8% CV. Analytical bias was within ±9.2% of target and extraction efficiencies were ≥72.9% for all analytes. Analytes were stable when stored at 22°C for 16 h, 4°C for 48 h, after three freeze–thaw cycles at −20°C and when stored on the autosampler for 48 h. This sensitive and specific 2D-GCMS assay provides a new means of simultaneously quantifying CBD, THC and metabolite biomarkers in clinical medicine, forensic toxicology, workplace drug testing, and driving under the influence of drugs programs.     

Direct coupling of a flow–flow electromembrane extraction probe to LC-MS

A fully integrated and automated electromembrane extraction LC-MS (EME-LC-MS) system has been developed and characterized. Hyphenation of a flow–flow EME probe to LC-MS was accomplished by using an in-built 10-port switching valve of the LC-MS system. The 10-port switching valve decoupled the high pressure of the UHPLC-system from the low pressure required for operation of the EME-probe by automated switching between a sample extraction/analysis and a sample load position. In the sample load position the extracted analytes were loaded into a HPLC sample loop. By switching the valve to the sample extraction/analysis position the setup allowed simultaneous analysis of previously loaded analytes while extracting a new sample. Performance of the system was characterized with respect to precision and linearity (RSD < 2.5%, R²: 0.998) and the setup was applied for studying the in-vitro metabolism of methadone by rat liver microsomes. As the metabolic reaction proceeded, methadone and its metabolites were extracted and analyzed in parallel by LC-MS using either isocratic or gradient elution. Compared to a conventional in-vitro metabolism analysis based on protein precipitation followed by LC-MS analysis the fully automated EME-LC-MS system offers a significant time saving and in addition demonstrates increased sensitivity as the analytes were automatically enriched during the extraction process. The experiment revealed 6 to 16 times higher S/N ratios of the EME-LC-MS method compared to protein precipitation followed by LC-MS and thus concomitantly lower LOD and LOQ. The setup integrates a complete analytical workflow of rapid extraction, enrichment, separation and detection of analytes in a fully automated manner. These attributes make the developed system a powerful alternative approach for a wide range of analytical applications.