In our work, we introduced a novel concept of the lab-in-a-syringe tests. We solved the problem of detection in already published LIS tests by putting all the reaction and detection pads directly into the syringe barrel. We also used more layers to make the results visible for users. Two detection layouts: (i) with using rounded pads-based detection, and (ii) with using rectangular detection pads, were studied. As the proof of concept, we studied the determination of Ni(II) using dimethylglyoxime as the reagent and blocking of the interference of Fe(II). The calibrations for Ni(II) at the optimal conditions has excellent R2 of 0.998 with production costs of 0.2 USD per one test.

• Klíčová slova
• Lab-in-a-syringe, Lateral-flow assay, Low-cost microfluidics, Sensing,
• MeSH
• biotest přístrojové vybavení   MeSH
• design vybavení MeSH
• injekční stříkačky * MeSH
• Publikační typ
• časopisecké články MeSH

About eight years ago, a new automation approach and flow technique called "Lab-In-Syringe" was proposed. It was derived from previous flow techniques, all based on handling reagent and sample solutions in a flow manifold. To date Lab-In-Syringe has evidently gained the interest of researchers in many countries, with new modifications, operation modes, and technical improvements still popping up. It has proven to be a versatile tool for the automation of sample preparation, particularly, liquid-phase microextraction approaches. This article aims to assist newcomers to this technique in system planning and setup by overviewing the different options for configurations, limitations, and feasible operations. This includes syringe orientation, in-syringe stirring modes, in-syringe detection, additional inlets, and addable features. The authors give also a chronological overview of technical milestones and a critical explanation on the potentials and shortcomings of this technique, calculations of characteristics, and tips and tricks on method development. Moreover, a comprehensive overview of the different operation modes of Lab-In-Syringe automated sample pretreatment is given focusing on the technical aspects and challenges of the related operations. We further deal with possibilities on how to fabricate required or useful system components, in particular by 3D printing technology, with over 20 different elements exemplarily shown. Finally, a short discussion on shortcomings and required improvements is given.

• Klíčová slova
• 3D printing of instrument elements, Lab-In-Syringe, automation of sample pretreatment, potentials and troubles, system setup and operation modes, tips and tricks in method development,
• MeSH
• chemické techniky analytické přístrojové vybavení   metody   normy   MeSH
• injekční stříkačky * MeSH
• laboratorní automatizace * MeSH
• limita detekce MeSH
• reprodukovatelnost výsledků MeSH
• Publikační typ
• časopisecké články MeSH

A novel approach to the automation technique Lab-In-Syringe, also known as In-Syringe Analysis, is proposed which utilizes a secondary inlet into the syringe void, used as a size-adaptable reaction chamber, via a channel passing through the syringe piston. This innovative approach allows straightforward automation of head-space single-drop microextraction, involving accurately controlled drop formation and handling, and the possibility of on-drop analyte quantification. The syringe was used in upside-down orientation and in-syringe magnetic stirring was carried out, which allowed homogenous mixing of solutions, promotion of head-space analyte enrichment, and efficient syringe cleaning. The superior performance of the newly developed system was illustrated with the development of a sensitive method for total ammonia determination in surface waters. It is based on head-space extraction of ammonia into a single drop of bromothymol blue indicator created inside the syringe at the orifice of the syringe piston channel and on-drop sensing of the color change via fiber optics. The slope of the linear relationship between absorbance and time was used as the analytical signal. Drop formation and performance of on-drop monitoring was further studied with rhodamine B solution to give a better understanding of the system's performance. A repeatability of 6% RSD at 10 μmol L(-1) NH3, a linear range of up to 25 μmol L(-1) NH3, and a limit of detection of 1.8 μmol L(-1) NH3 were achieved. Study of interferences proved the high robustness of the method towards humic acids, high sample salinity, and the presence of detergents, thus demonstrating the method superiority compared to the state-of-the-art gas-diffusion methods. A mean analyte recovery of 101.8% was found in analyzing spiked environmental water samples.

• Klíčová slova
• Ammonia, Automation of sample preparation, Bromothymol blue indicator, Head-space Single-Drop Microextraction, Kinetic on-drop sensing, Lab-In-Syringe,
• Publikační typ
• časopisecké články MeSH

Two operational modes for Lab-In-Syringe automation of direct-immersion single-drop microextraction have been developed and critically compared using lead in drinking water as the model analyte. Dithizone was used in the presence of masking additives as a sensitive chromogenic complexing reagent. The analytical procedure was carried out inside the void of an automatic syringe pump. Normal pump orientation was used to study extraction in a floating drop of a toluene-hexanol mixture. Placing the syringe upside-down allowed the use of a denser-than-water drop of chloroform for the extraction. A magnetic stirring bar was placed inside the syringe for homogenous mixing of the aqueous phase and enabled in-drop stirring in the second configuration while resulting in enhanced extraction efficiency. The use of a syringe as the extraction chamber allowed drop confinement and support by gravitational differences in the syringe inlet. Keeping the stirring rates low, problems related to solvent dispersion such as droplet collection were avoided. With a drop volume of 60 µL, limits of detection of 75 nmol L-1 and 23 nmol L-1 were achieved for the floating drop extraction and the in-drop stirring approaches, respectively. Both methods were characterized by repeatability with RSD typically below 5%, quantitative analyte recoveries, and analyte selectivity achieved by interference masking. Operational differences were critically compared. The proposed methods permitted the routine determination of lead in drinking water to be achieved in less than 6 min.

• Klíčová slova
• Automation, Direct-immersion single-drop microextraction, Drinking water, In-drop stirring microextraction, Lab-In-Syringe, Lead, dithizone assay,
• MeSH
• automatizace * MeSH
• injekční stříkačky * MeSH
• magnetické jevy MeSH
• mikroextrakce kapalné fáze * přístrojové vybavení   MeSH
• olovo analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• olovo MeSH

BACKGROUND: Alkylphenols are water contaminants of strong endocrine disruptive potential. Sample preparation is generally imperative to improve sensitivity and minimize matrix effects. Dispersive solid phase extraction is a powerful alternative to cartridge-based sorbent extraction omitting backpressure problems and reducing procedural time. Herein, solvent-dissolvable sorbents offer the advantages of easy and cost-efficient production, efficiency, and full analyte recovery, while eluates can be directly submitted to instrumental determination. Despite the potential to reduce environmental impact and enhance reproducibility, there is a lack of automation attempts. RESULTS: A fully automated solvent-assisted dispersive solid phase extraction method was developed for selected alkylphenols based on the technique Lab-In-Syringe. The void of automatic bidirectional syringe pump was used as mixing and extraction vessel. The iron(III) thenoyltrifluoroacetonate complex was used as novel dissolvable sorbent. 40 μL complex solution was dispersed in the sample, leading to the precipitation of 0.4 mg sorbent. Extraction occurred within 40 s and was accelerated by in-syringe magnetic stirring. The sorbent was retained on a melamine foam packing in the syringe inlet, dissolved in a methanolic solution of ascorbic acid, and injected into online-coupled HPLC. Linear working ranges were achieved from 1 to 1000 μg/L with sub-ppb detection limits and accuracies ranging from 98.3 to 110 %. SIGNIFICANCE: In this work, we explored for the first time automated in-syringe automated dispersive SPE based on a dissolvable sorbent. Parallel operation of sample pretreatment and separation enabled throughputs of 4.5/h with typically <5 % RSD and preconcentrations of 16.4-21.2. AGREE greenness evaluation yielded a score of 0.59.

• Klíčová slova
• Alkylphenols, High performance liquid chromatography, Iron(III) thenoyltrifluoroacetonate complex, Lab-in-syringe automation, Solvent-assisted dispersive solid phase Extraction,
• MeSH
• adsorpce MeSH
• automatizace MeSH
• chemické látky znečišťující vodu * analýza   izolace a purifikace   MeSH
• chromatografie kapalinová MeSH
• fenoly * analýza   izolace a purifikace   chemie   MeSH
• injekční stříkačky MeSH
• limita detekce MeSH
• mikroextrakce na pevné fázi * přístrojové vybavení   metody   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• železité sloučeniny * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• fenoly * MeSH
• železité sloučeniny * MeSH

We report on the hyphenation of the modern flow techniques Lab-In-Syringe and Lab-On-Valve for automated sample preparation coupled online with high-performance liquid chromatography. Adopting the bead injection concept on the Lab-On-Valve platform, the on-demand, renewable, solid-phase extraction of five nonsteroidal anti-inflammatory drugs, namely ketoprofen, naproxen, flurbiprofen, diclofenac, and ibuprofen, was carried out as a proof-of-concept. In-syringe mixing of the sample with buffer and standards allowed straightforward pre-load sample modification for the preconcentration of large sample volumes. Packing of ca. 4.4 mg microSPE columns from Oasis HLB® sorbent slurry was performed for each sample analysis using a simple microcolumn adapted to the Lab-On-Valve manifold to achieve low backpressure during loading. Eluted analytes were injected into online coupled HPLC with subsequent separation on a Symmetry C18 column in isocratic mode. The optimized method was highly reproducible, with RSD values of 3.2% to 7.6% on 20 µg L-1 level. Linearity was confirmed up to 200 µg L-1 and LOD values were between 0.06 and 1.98 µg L-1. Recovery factors between 91 and 109% were obtained in the analysis of spiked surface water samples.

• Klíčová slova
• Lab-In-Syringe, Lab-On-Valve, bead injection, high-performance liquid chromatography, nonsteroidal anti-inflammatory drugs, online coupling, water analysis,
• MeSH
• antiflogistika nesteroidní analýza   MeSH
• extrakce na pevné fázi * MeSH
• povrchové vlastnosti MeSH
• voda chemie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antiflogistika nesteroidní MeSH
• voda MeSH

A sample preparation method involving tandem implementation of protein precipitation and salting-out homogenous liquid-liquid extraction was developed for the determination of beta-blockers in serum. The entire procedure was automated using a computer-controlled syringe pump following the Lab-In-Syringe approach. It is based on the denaturation of serum proteins with acetonitrile followed by salt-induced phase separation upon which the proteins accumulate as a compact layer at the interphase of the solutions. The extract is then separated and diluted in-syringe before being submitted to online coupled UHPLC-MS/MS. A 1 mL glass syringe containing a small stir bar for solution mixing at up to 3000 rpm, was used to deal with sample volumes as small as 100 μL. A sample throughput of 7 h-1 was achieved by performing the chromatographic run and sample preparation procedure in parallel. Linear working ranges were obtained for all analytes between 5 and 100 ng mL-1, with LOD values ranging from 0.4 to 1.5 ng mL-1. Accuracy values in the range of 88.2-106% and high precision of <11% RSD suggest applicability for routine analysis that can be further improved using deuterated standards.

• Klíčová slova
• Beta-blockers, Centrifugation-less protein precipitation, Lab-in-syringe automation, Salting-out homogenous liquid-liquid extraction, Serum,
• MeSH
• chlorid sodný MeSH
• extrakce kapalina-kapalina metody   MeSH
• injekční stříkačky * MeSH
• tandemová hmotnostní spektrometrie * MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chlorid sodný MeSH

Online coupling of Lab-In-Syringe automated headspace extraction to gas chromatography has been studied. The developed methodology was successfully applied to surface water analysis using benzene, toluene, ethylbenzene, and xylenes as model analytes. The extraction system consisted of an automatic syringe pump with a 5 mL syringe into which all solutions and air for headspace formation were aspirated. The syringe piston featured a longitudinal channel, which allowed connecting the syringe void directly to a gas chromatograph with flame ionization detector via a transfer capillary. Gas injection was achieved via opening a computer-controlled pinch valve and compressing the headspace, upon which separation was initialized. Extractions were performed at room temperature; yet sensitivity comparable to previous work was obtained by high headspace to sample ratio VHS/VSample of 1.6:1 and injection of about 77% of the headspace. Assistance by in-syringe magnetic stirring yielded an about threefold increase in extraction efficiency. Interferences were compensated by using chlorobenzene as an internal standard. Syringe cleaning and extraction lasting over 10 min was carried out in parallel to the chromatographic run enabling a time of analysis of <19 min. Excellent peak area repeatabilities with RSD of <4% when omitting and <2% RSD when using internal standard corrections on 100 μg L-1 level were achieved. An average recovery of 97.7% and limit of detection of 1-2 μg L-1 were obtained in analyses of surface water.

• Klíčová slova
• Btex, Gas chromatography – flame ionization detection, Headspace extraction, Magnetic-stirring Lab-In-Syringe, On-line coupling,
• MeSH
• automatizace MeSH
• benzen analýza   izolace a purifikace   MeSH
• benzenové deriváty analýza   izolace a purifikace   MeSH
• limita detekce MeSH
• mikroextrakce na pevné fázi MeSH
• plamínková ionizace metody   MeSH
• teplota MeSH
• toluen analýza   izolace a purifikace   MeSH
• voda chemie   MeSH
• xyleny analýza   izolace a purifikace   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• benzen MeSH
• benzenové deriváty MeSH
• ethylbenzene MeSH Prohlížeč
• toluen MeSH
• voda MeSH
• xyleny MeSH

Lab-In-Syringe direct immersion single drop microextraction is proposed as an automated sample pretreatment methodology and coupled online to HPLC with fluorescence detection for the determination of fluoroquinolones in environmental waters. For the first time, a drop of a natural deep eutectic solvent (NADES), synthesized from hexanoic acid and thymol, has been used as an extractant in automated single-drop microextraction. The extraction procedure was carried out within the 5 mL void of an automatic syringe pump. A 9-position head valve served the aspiration of all required solutions, air, waste disposal, and hyphenation with the HPLC instrument. Sample mixing during extraction was done by a magnetic stirring bar placed inside the syringe. Only 60 μL of NADES were required omitting toxic classical solvents and improving the greenness of the proposed methodology. By direct injection, linear working ranges between 0.1 and 5 μg L-1 were achieved for all fluoroquinolones. The limit of quantification values and enrichment factors ranged from 20 ng L-1 to 30 ng L-1 and 35 to 45, respectively. Accuracies obtained from the analysis of spiked surface water and wastewater treatment plant effluent analysis at two concentration levels (0.5 and 4 μg L-1) ranged from 84.6% to 119.7%, with RSD values typically <3%.

• Klíčová slova
• Automation of sample preparation, Directly immersed single drop microextraction, Fluoroquinolone antibiotics, Lab-in-syringe, Natural deep eutectic solvent, Online coupling to HPLC,
• MeSH
• automatizace MeSH
• fluorochinolony * MeSH
• hluboce eutektická rozpouštědla MeSH
• injekční stříkačky MeSH
• limita detekce MeSH
• mikroextrakce kapalné fáze * metody   MeSH
• ponoření MeSH
• rozpouštědla chemie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fluorochinolony * MeSH
• hluboce eutektická rozpouštědla MeSH
• rozpouštědla MeSH

An automated methodology for magnetic dispersive solid phase microextraction integrating bead injection approach for renewable sorbent introduction is presented for the first time and was successfully applied to the enrichment of water contaminants. For this purpose, a simple procedure was developed for the functionalization of commercial SupelTM-Select HLB (Hydrophilic modified styrene polymer) sorbent beads that allowed embedding magnetite nanoparticles (Fe3O4). The sorbent was then used in a dispersive solid phase extraction procedure that was carried out entirely inside the void of an automatic syringe pump following the flow-batch concept of Lab-In-Syringe including automated renewal of the sorbent for each analysis. Mixing processes, sorbent dispersion, and sorbent recovery were enabled by using a strong magnetic stirring bar, fabricated from a 3D printed polypropylene casing and neodymium magnets, inside the syringe. The final extract was submitted to online coupled liquid chromatography with spectrometric detection. System and methodology were applied to determine mebendazole, bisphenol A, benzyl 4-hydroxybenzoate, diclofenac, and triclosan selected as models from different groups of environmental contaminants of current concern. Experimental parameters including extraction and elution times, composition and volume of eluent, and bead recollection were optimized. Required system elements were produced by 3D printing. Enlarging the sample volume by repeated extraction to enhance the sensitivity of the method was studied. Using double extraction from 3.5 mL, limits of detection ranged from 1.2 μg L-1 to 6.5 μg L-1 with an RSD (n = 6) value less than 7% for all the analytes at 25 μg L-1 level. The method was linear in the range of 5-200 μg L-1 and was successfully implemented for the analysis of surface waters with analyte recoveries ranging from 78.4% to 105.6%.

• Klíčová slova
• Dispersive solid phase extraction, Environmental contaminants, High-performance liquid chromatography, Lab-in-syringe automation technique, Magnetic-functionalized sorbents,
• MeSH
• extrakce na pevné fázi MeSH
• injekční stříkačky MeSH
• oxid železnato-železitý * MeSH
• voda * chemie   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid železnato-železitý * MeSH
• voda * MeSH