automation of sample pretreatment
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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.
For the pretreatment of wood, charcoal and collagen from bone micro samples using the Acid-Base-Acid (ABA) method, we have assembled an automated computer-controlled unit in our laboratory CRL. The sample is placed in a glass single-necked cuvette. The machine consists of prepared solutions which are guided through capillaries, switching valve and peristaltic pump into the cuvette with the sample according to the currently selected program. The automat can be used for the pretreatment of charcoal, wood and also collagen from bones.
- MeSH
- alkálie chemie MeSH
- dřevěné a živočišné uhlí chemie MeSH
- dřevo chemie MeSH
- kolagen chemie MeSH
- kosti a kostní tkáň chemie MeSH
- kyseliny chemie MeSH
- laboratorní automatizace metody MeSH
- lidé MeSH
- radioaktivní datování metody MeSH
- radioizotopy uhlíku analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
A cheap, disposable sample pretreatment device with planar supported liquid membrane (SLM) was proposed, assembled and placed into an autosampler carousel of a commercial capillary electrophoresis (CE) instrument for automated pretreatment and analysis of formate in undiluted whole blood and serum samples. All analytical procedures except for filling the pretreatment device with donor and acceptor solutions, i.e., extraction across SLM, injection of the extracted sample and CE-UV determination of formate, were performed fully automatically. The pretreatment device required only μL volumes of blood sample and organic solvent per extraction and was disposed off after each extraction. Good repeatability of peak areas (≤7.7%) and migration times (≤1.5%), linear relationship (r(2)=0.998-0.999) and limits of detection (≤35μM) were achieved. The overall analytical process including blood withdrawal, filling the SLM device with respective solutions, extraction of blood sample, injection into separation capillary and CE separation of formate from other anions took less than 4min. The method was proved useful by direct determination of elevated formate concentrations in undiluted serum samples of a methanol intoxicated patient. Due to its compatibility with currently commercially available CE instrumentation, disposability of extraction devices, minimum sample handling/consumption, and short extraction/analysis times, the developed method might be attractive for rapid diagnosis of methanol poisoning in clinical and toxicological laboratories.
- MeSH
- elektroforéza kapilární metody MeSH
- formiáty krev MeSH
- lidé MeSH
- reprodukovatelnost výsledků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Over the last five decades, many methods to analyze thiamine (vitamin B1) and its phosphorylated forms in urine, whole blood, serum, plasma and erythrocytes have been proposed. Some of the methods are presently used in routine practice, but analytical problems regarding reproducibility, standardization, lack of automation, time consuming procedures for pretreatment and analysis are often discussed. With modern approaches to bioanalysis in clinical research of vitamins, whole processes can be automated, making analysis less time consuming, with reduced consumption of solvents and samples. This review critically discusses various analytical techniques, their advantages and disadvantages that are used for determination of thiamine and its derivatives in clinical practice, with emphasis on accurate, reliable and fast analytical procedures.
- MeSH
- erytrocyty chemie MeSH
- klinická chemie normy trendy MeSH
- lidé MeSH
- referenční standardy MeSH
- reprodukovatelnost výsledků MeSH
- thiamin analýza krev moč MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
INTRODUCTION: The analysis of plant and herbal samples is a challenging task for analytical chemists due to the complexity of the matrix combined with the low concentration of analytes. In recent years different liquid-phase microextraction (LPME) techniques coupled with a variety of analytical equipment have been developed for the determination of both organic and inorganic analytes. OBJECTIVE: Over the past few years, the number of research papers in this field has shown a markedly growing tendency. Therefore, the purpose of this review paper is to summarise and critically evaluate research articles focused on the application of LPME techniques for the analysis of plant and herbal samples. RESULTS: Due to the complex nature of the samples, the direct application of LPME techniques to the analysis of plants has not often been done. LPME techniques as well as their modalities have been commonly applied in combination with other pretreatment techniques, including a solid-liquid extraction technique supported by mechanical agitation or auxiliary energies for plant analysis. Applications and the most important parameters are summarised in the tables. CONCLUSION: This review summarises the application of the LPME procedure and shows the major benefits of LPME, such as the low volume of solvents used, high enrichment factor, simplicity of operation and wide selection of applicable detection techniques. We can expect further development of microextraction analytical methods that focus on direct sample analysis with the application of green extraction solvents while fully automating procedures for the analysis of plant materials.
- MeSH
- mikroextrakce kapalné fáze * MeSH
- rostliny MeSH
- rozpouštědla MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Reaching trace amounts of mycotoxin contamination requires sensitive and selective analytical tools for their determination. Improving the selectivity of sample pretreatment steps covering new and modern extraction techniques is one way to achieve it. Molecularly imprinted polymers as selective sorbent for extraction undoubtedly meet these criteria. The presented work is focused on the hyphenation of on-line molecularly imprinted solid-phase extraction with a chromatography system using a column-switching approach. Making a critical comparison with a simultaneously developed off-line extraction procedure, evaluation of pros and cons of each method, and determining the reliability of both methods on a real sample analysis were carried out. Both high-performance liquid chromatography methods, using off-line extraction on molecularly imprinted polymer and an on-line column-switching approach, were validated, and the validation results were compared against each other. Although automation leads to significant time savings, fewer human errors, and required no handling of toxic solvents, it reached worse detection limits (15 versus 6 μg/L), worse recovery values (68.3-123.5 versus 81.2-109.9%), and worse efficiency throughout the entire clean-up process in comparison with the off-line extraction method. The difficulties encountered, the compromises made during the optimization of on-line coupling and their critical evaluation are presented in detail.
This work presents the development of a fully automated flow-batch analysis (FBA) system as a new approach for on-line preconcentration, photodegradation and fluorescence detection in a lab-constructed mixing chamber that was designed to perform these processes without sample dispersion. The system positions the mixing chamber into the detection system and varies the instrumental parameters according to the required photodegradation conditions. The developed FBA system is simple and easily coupled with any sample pretreatment without altering the configuration. This FBA system was implemented to photodegrade and determine the fluorescence of the degradation products of metsulfuron methyl (MSM), a naturally non-fluorescent herbicide of the sulfonylurea׳s family. An on-line solid phase extraction (SPE) and clean up procedure using a C18 minicolumn was coupled to the photodegradation-detection mixing chamber (PDMC) that was located in the spectrofluorometer. An enrichment factor of 27 was achieved. Photodegradation conditions have been optimized by considering the influence of the elution solvent on both the formation of the photoproduct and on the fluorescence signal. Under optimal conditions, the calibration for the MSM determination was linear over the range of 1.00-7.20 µg L(-1). The limit of detection (LOD) was 0.28 µg L(-1); the relative standard deviation was 2.0% and the sample throughput for the entire process was 3h(-1). The proposed method was applied to real water samples from the Bahía Blanca׳s agricultural region (Bahía Blanca, Buenos Aires, Argentina). This method obtained satisfactory recoveries with a range of 94.7-109.8%.
- MeSH
- arylsulfonany analýza MeSH
- extrakce na pevné fázi MeSH
- fluorescenční spektrometrie MeSH
- fotochemie metody MeSH
- fotolýza MeSH
- herbicidy analýza MeSH
- kalibrace MeSH
- koncentrace vodíkových iontů MeSH
- látky znečišťující vodu analýza MeSH
- limita detekce MeSH
- reprodukovatelnost výsledků MeSH
- sulfonylmočovinové sloučeniny analýza MeSH
- světlo MeSH
- technologie zelené chemie MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
