Liquid Reagents Research Articles

Comparative assessment of a foam-based oxidative treatment of hydrocarbon-contaminated unsaturated and anisotropic soils

In situ delivery of liquid reagents in vadose zone is limited by soil anisotropy and gravity. The enhanced delivery of persulfate (PS) as oxidant, using a new foam-based method (F-PS) was compared at bench-scale to traditional water-based (W-PS) and surfactant solution-based (S-PS) deliveries. The goal was to distribute PS uniformly in coal tar-contaminated unsaturated and anisotropic soils, both in terms of permeability and contamination. Water was the less efficiently delivered fluid because of the hydrophobicity of the contaminated soils. Surfactant enhanced PS-distribution into contaminated zones by reducing interfacial tension and inverting soil wettability. Regardless of coal tar contamination contrasts (0 vs. 5 and 1 vs. 10 g kg soil−1) or strong permeability contrasts, PS-solution injection after foam injection led to the most uniform reagents delivery. While PS-concentration varied more than 5-times between zones using W-PS and S-PS methods, it varied less than 1.6-times when the F-PS one was used. Finally, despite unfavorable conditions, the foam-based method did not show any detrimental effect regarding the oxidation of hydrocarbons compared to the W-PS and S-PS methods carried out in ideal conditions. Moreover, hydrocarbon degradation rates were slightly higher when using F-PS than S-PS due to a lower surfactant content in the targeted zone.

Rapid and Automated Detection of Six Contaminants in Milk Using a Centrifugal Microfluidic Platform with Two Rotation Axes.

Antibiotic residues and illegal additives are among the most common contaminants in milk and other dairy products, and they have become essential public health concerns. To ensure the safety of milk, rapid and convenient screening methods are highly desired. Here, we integrated microarray technology into a microfluidic device to achieve rapid, sensitive, and fully automated detection of chloramphenicol, tetracyclines, enrofloxacin, cephalexin, sulfonamides, and melamine in milk on a centrifugal microfluidic platform with two rotation axes. All the liquid reagent for the immunoassay was prestored in the reagent chambers of the microdevice and can be released on demand. The whole detection can be automatically accomplished within 17 min, and the limits of detection were defined as 0.92, 1.01, 1.83, 1.14, 1.96, and 7.80 μg/kg for chloramphenicol, tetracycline (a typical drug of tetracyclines), enrofloxacin, cephalexin, sulfadiazine (a typical drug of sulfonamides), and melamine, respectively, satisfying the national standards for maximum residue limits in China. Raw milk samples were used to test the performance of the current immunoassay system, and the recovery rates in the repeatability tests ranged from 80 to 111%, showing a good performance. In summary, the immunoassay system established in this study can simultaneously detect six contaminants of four samples in a fully automated, cost-effective, and easy-to-use manner and thus has great promise as a screening tool for food safety testing.

A Modified Traveling Wave Ion Mobility Mass Spectrometer as a Versatile Platform for Gas-Phase Ion-Molecule Reactions.

Taken individually, chemical labeling and mass spectrometry are two well-established tools for the structural characterization of biomolecular complexes. A way to combine their respective advantages is to perform gas-phase ion-molecule reactions (IMRs) inside the mass spectrometer. This is, however, not so well developed because of the limited range of usable chemicals and the lack of commercially available IMR devices. Here, we modified a traveling wave ion mobility mass spectrometer to enable IMRs in the trapping region of the instrument. Only one minor hardware modification is needed to allow vapors of a variety of liquid reagents to be leaked into the trap traveling wave ion guide of the instrument. A diverse set of IMRs can then readily be performed without any loss in instrument performance. We demonstrate the advantages of implementing IMR capabilities in general, and to this quadrupole-ion mobility-time-of-flight (Q-IM-TOF) mass spectrometer in particular, by exploiting the full functionality of the instrument, including mass selection, ion mobility separation, and post-mobility fragmentation. The potential to carry out gas-phase IMR kinetics experiments is also illustrated. We demonstrate the versatility of the setup using gas-phase IMRs of established utility for biological mass spectrometry, including hydrogen-deuterium exchange, ion-molecule proton transfer reactions, and covalent modification of DNA anions using trimethylsilyl chloride.

Eight-color panel for immune phenotype monitoring by flow cytometry

Flow cytometry (FC) is a fast and highly informative technology that has gained prominence in immune phenotype monitoring. FC standardization is crucial to obtain reliable results that are comparable among laboratories and immune monitoring studies, as this method is influenced by several variables, including equipment, reagents, staining procedures, and pre-analytical and analytical factors. Recent studies have standardized antibody panels and analytical procedures to analyze circulating immune cells in peripheral blood (PB). However, these panels cannot be adapted for laboratories that perform eight-color FC with liquid reagents. The aim of this study was to design and test an eight-color panel, intended to phenotype the main immune cell subsets in PB using liquid reagents and fresh whole blood samples. Samples were collected from healthy individuals recruited from staff and students and from six chemotherapy patients with leukopenia. The antibody panel was designed on the basis of previous studies. Quality controls comprised antibody titration, fluorescence minus one controls, internal controls, and compensation controls. Samples were analyzed by two operators using an eight-color three-laser FACSCanto II flow cytometer (BD Biosciences, USA) and Infinicyt software (Cytognos, Spain). The proposed eight-color panel is composed of six tubes. Analysis of these tubes allowed evaluation of frequencies and classification of various immune cells, such as naïve T, central memory T, effector memory T, CDRA+ effector memory T, activated T, and regulatory T cells; class-switched B, non-switched B, memory B, regulatory B cells, and plasmablasts; myeloid and plasmacytoid dendritic cells, classical and non-classical monocytes; and immature neutrophils. Immunophenotyping of leukocytes using the proposed panel was efficient to correctly differentiate the majority of immune cell subtypes. It is a promising tool to determine the immunological profile of patients in clinical trials and establish associations with disease prognosis, complications, and outcomes.

Vortex assisted in situ ionic liquid dispersive liquid–liquid microextraction for preconcentration of uranyl ion in water samples before spectrophotometric detection

Vortex assisted in situ ionic liquid dispersive liquid–liquid microextraction method was developed for extraction of U(VI) from aqueous solutions using hydrophilic ionic liquid and ion-exchange reagent. Arsenazo III was used as a complexing agent in microextraction process. Under optimized conditions, the proposed method for uranyl ion exhibited good precision, 5.2% for 1 µg L−1 and 5.1% for 4 µg L−1, low limit of detection, 0.06 µg L−1 and high enrichment factor, 91. The accuracy studies were achieved by spiking of 1 and 5 µg L−1 U(VI) into water samples and the recovery was found in the range of 99–111%.

Direct Observation of Early Stages of Growth of Multilayered DNA-Templated Au-Pd-Au Core-Shell Nanoparticles in Liquid Phase.

We report here on direct observation of early stages of formation of multilayered bimetallic Au-Pd core-shell nanocubes and Au-Pd-Au core-shell nanostars in liquid phase using low-dose in situ scanning transmission electron microscopy (S/TEM) with the continuous flow fluid cell. The reduction of Pd and formation of Au-Pd core-shell is achieved through the flow of the reducing agent. Initial rapid growth of Pd on Au along <111> direction is followed by a slower rearrangement of Pd shell. We propose the mechanism for the DNA-directed shape transformation of Au-Pd core-shell nanocubes to adopt a nanostar-like morphology in the presence of T30 DNA and discuss the observed nanoparticle motion in the confined volume of the fluid cell. The growth of Au shell over Au-Pd nanocube is initiated at the vertices of the nanocubes, leading to the preferential growth of the {111} facets and resulting in formation of nanostar-like particles. While the core-shell nanostructures formed in a fluid cell in situ under the low-dose imaging conditions closely resemble those obtained in solution syntheses, the reaction kinetics in the fluid cell is affected by the radiolysis of liquid reagents induced by the electron beam, altering the rate-determining reaction steps. We discuss details of the growth processes and propose the reaction mechanism in liquid phase in situ.

Self‐Powered Electrowetting Valve for Instantaneous and Simultaneous Actuation of Paper‐Based Microfluidic Assays

AbstractIn this work, a self‐powered electrowetting valve (SPEV) driven by an energy‐harvesting triboelectric nanogenerator (TENG) is reported. The TENG (5 × 5 cm2) can produce an open‐circuit voltage of 380 V by applying a mechanical stimulus, which is much higher than the actuation voltage of the SPEV (130 V). Once actuated, the electrowetting valve can be instantly switched on at a response time of 0.18 s, allowing liquid reagent to flow through the valve. The SPEV can be used for simultaneous addition of multiple reagents in an enzyme‐linked immunosorbent assay on a paper‐based microfluidic analytical device (µPAD). This assay involves a chromogenic reaction that achieves effective detection of alpha‐fetoprotein, a critical tumor marker for early diagnosis of liver cancer. The SPEV reported in this work can be potentially used in other complex multiprocedure µPADs, which will potentially enable portable, accessible, and cost‐effective assays for early diagnosis, food safety, pollution detection, etc.

In‐Transit Electroextraction of Small‐Molecule Pharmaceuticals from Blood

AbstractAn electrokinetic platform was developed for extracting small‐molecule pharmaceuticals from a dried blood spot. Through the exclusion of liquid reagents and use of low field strength (6 V cm−1), the electroextraction of a drug from a dried blood spot, deposited on a polymer inclusion membrane (PIM), could be realised while in transit in the mail. In transit sample preparation provides a potential solution to in situ sample degradation and may accelerate the workflow upon arrival of a patient sample at the analytical facility. The electroextraction method was enabled through our discovery of the use of 15–20 μm thin PIMs as electrophoretic separation medium in absence of liquid reagents. Here, a PIM consisting of cellulose triacetate as polymer base, 2‐nitrophenyl octyl ether as plasticizer and 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide as carrier was used. The PIM, was packaged with two 12 V batteries to supply the separation voltage. A blood spot containing berberine chloride was deposited and dried before the applying the separation potential, allowing for the electroextraction while the packaged device was shipped in internal mail. Upon arrival in the analytical laboratory, the PIM was analysed using a fluorescence microscope with photon multiplier tube, quantifying the berberine extracted away from the sample matrix. This platform represents a new opportunity for processing clinical samples during transport to the laboratory, saving time and manual handling to accelerate the time to result.

In-Transit Electroextraction of Small-Molecule Pharmaceuticals from Blood.

An electrokinetic platform was developed for extracting small-molecule pharmaceuticals from a dried blood spot. Through the exclusion of liquid reagents and use of low field strength (6 V cm-1 ), the electroextraction of a drug from a dried blood spot, deposited on a polymer inclusion membrane (PIM), could be realised while in transit in the mail. In transit sample preparation provides a potential solution to in situ sample degradation and may accelerate the workflow upon arrival of a patient sample at the analytical facility. The electroextraction method was enabled through our discovery of the use of 15-20 μm thin PIMs as electrophoretic separation medium in absence of liquid reagents. Here, a PIM consisting of cellulose triacetate as polymer base, 2-nitrophenyl octyl ether as plasticizer and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide as carrier was used. The PIM, was packaged with two 12 V batteries to supply the separation voltage. A blood spot containing berberine chloride was deposited and dried before the applying the separation potential, allowing for the electroextraction while the packaged device was shipped in internal mail. Upon arrival in the analytical laboratory, the PIM was analysed using a fluorescence microscope with photon multiplier tube, quantifying the berberine extracted away from the sample matrix. This platform represents a new opportunity for processing clinical samples during transport to the laboratory, saving time and manual handling to accelerate the time to result.

Detection of Minimal Residual Disease in B Cell Acute Lymphoblastic Leukemia Using an Eight-Color Tube with Dried Antibody Reagents.

Flow cytometry is a powerful tool for the detection of minimal residual disease (MRD) of B cell precursor acute lymphoblastic leukemia (BCP-ALL) patients. However, the staining process and the choice of antibodies rely on laboratory expertise and may be source of variability or technical errors. Recently, Beckman Coulter commercialized a ready to use tube with dried format reagents for BCP-ALL MRD detection. The aim of this study is to evaluate the applicability of this tube and to compare it to a conventional (liquid format reagents) method. Thirty-one samples from B ALL patients were analyzed: 19 bone marrow (BM) aspirations, 10 peripheral blood (PB) samples and 2 cerebrospinal fluids at different stages of the follow-up. In addition, we tested 5 bone marrow samples mixed into non-pathological (control) bone marrow. The dried format tube included seven antibodies: CD45Kro, CD58FITC, CD34ECD, CD10PC5.5, CD19PC7, CD38AA700, CD20AA750, with possibility of additional antibodies for blast markers identified at diagnosis. For comparison, a liquid format tube was prepared, and considered as the reference. This tube was validated for daily routine laboratory, with satisfying qualitative (MRD + or MRD-) and quantitative (MRD percentages) correlation with the reference tube. With this single dried format tube, we showed interesting results for BCP-ALL MRD detection in the aim of standardization and reliable interlaboratory results. It allows accurate MRD detection including low levels (10-4), and offers possibility to increase performance (supplementary antibody) within a preestablished effective antibody panel for BCP-ALL MRD. © 2018 International Clinical Cytometry Society.

Facile and Efficient Gas-Phase Pressure-Controlled Thermal Functionalization of Nanocrystalline Porous Silicon with 1-Hexene

Substitution of hydrogen at porous silicon (PSi) surface by organic groups can be done via thermally activated hydrosilylation reactions in which PSi is left for several hours into liquid alkenes at temperatures typically over 100°C. For alkenes whose boiling points are below 100°C (e.g. 1-heptene and shorter molecules), the process suffers from high reagent boiling and evaporation. Gas-phase hydrosilylation is an alternative when using short molecules. It has not been as extensively studied, and was mainly done in plasma reactors with silicon nanocrystals. Here we present a new method for facile gas-phase thermally-activated hydrosilylation in PSi, but using liquid solutions as reagent (1-hexene was used here). PSi and liquid alkene are loaded at room temperature into a chamber which is then closed and heated up to a temperature greater than the alkene boiling point. The effects of process temperature, time and pressure were investigated by means of Fourier transform infrared spectroscopy. The maximum theoretical derivatization efficiency was achieved with optimized parameters. The derivatization was uniform across the PSi layer depth. PSi luminescence was effectively stabilized by the process. The new gas-phase method presented here is facile, requires very small amount of liquid reagent, and is useful for attachment of short molecules to PSi or other materials surface.

A comparison of the new ROTEM®sigma with its predecessor, the ROTEMdelta

Thromboelastometry point-of-care coagulation testing facilitates optimised management of bleeding. Previous thromboelastometry systems required the blood sample and liquid reagents to be pipetted in several manual steps by trained personnel. The ROTEMsigma coagulation analyser is a fully automated point-of-care device. We aimed to assess the reference ranges of the new device and to compare the results with those of the predecessor device, the ROTEMdelta. We took blood from healthy volunteers and from hyper- or hypocoagulable patients; blood samples from healthy volunteers served to determine reference ranges for the most important parameters for the ROTEMsigma: CTEXTEM 48-61s; A5EXTEM 30-51mm; MCFEXTEM 54-70mm; CTINTEM 138-174s; MCFINTEM 51-67mm and MCFFIBTEM 5-24mm. We then used blood samples from patients to compare the results obtained between the old and the new device. We found a strong correlation between the same tests performed on two ROTEMsigma devices and between the ROTEMsigma and the ROTEMdelta with respect to the determination of thromboelastometry parameters of hyper- and hypocoagulable patients (all p<0.001 and R>0.8). Performance evaluation for the ROTEMsigma device showed very high precision (R>0.99, p<0.001). Our reference ranges can serve as an important aid for other hospitals using this new device.

A novel chemical lysis method for maximum release of DNA from difficult-to-lyse bacteria

Molecular detection of microorganisms requires releasing DNA from cells. However, since certain microbial organisms are refractory to lysis by chemical or enzymatic methods, mechanical lysis by bead-beating is typically employed to disrupt difficult-to-lyse microbes. A newly developed chemical lysis method called sporeLYSE enables release of DNA from difficult-to-lyse microbes without bead-beating. The sporeLYSE method was compared to bead-beating and an alkaline/detergent lysis solution for releasing DNA from microbes grown in vitro, including surrogates of Category A bioterrorism agents. sporeLYSE released 83% to 100% of DNA from Mycobacterium smegmatis, Francisella philomiragia, Yersinia enterocolitica, Bacillus thuringiensis, Pseudomonas aeruginosa, Moraxella catarrhalis and Klebsiella pneumoniae. qPCR results indicated that sporeLYSE extracted an equal or greater amount of DNA than either bead-beating or alkaline/detergent lysis from Gram-positive and Gram-negative bacteria. When sporeLYSE was used to extract DNA from saliva and sputum spiked with M. smegmatis and M. tuberculosis, respectively, the qPCR Ct values were 4–8 cycles lower than those for extractions via alkaline/detergent lysis and heat. Mean Ct values for sporesLYSE extractions from spores of Clostridium difficile and C. botulinum were approximately two cycles lower than those of MagNA Pure DNA extractions. Our results suggest that sporeLYSE is an easy-to-use liquid reagent that can efficiently release large amounts of DNA from a variety of bacteria, including spores.

Electromagnetic Fields in Technology of Processing of Polymeric Materials

The issues related to the implementation of the process of depolymerizing of waste polymers, initiated by thermal action of an intense electromagnetic microwave field, are considered. The reactions considered are distinguished by the possibility of reducing the initial monomers or oligomers. The required reaction temperatures are achieved by indirect heating due to the presence of carbon thermal converters in the mixture or the use of liquid reagents characterized by high microwave losses. The results of the study of two different mechanisms of depolymerizing, namely the decomposition of the polymer in a glycol medium and thermal decomposition, are shown. The methods of mathematical modeling of the joint problem of electrodynamics and heat conduction are analyzed to estimate the temperature regimes of the processes of thermal decomposition of polymers. Experimental studies are illustrated by examples of the depolymerizing of polyethylene terephthalate, polystyrene and polymethyl methacrylate, the destruction products of which were esters of terephthalic acid, styrene and methyl methacrylate.

Radionuclides in Irradiated Graphite of Uranium–Graphite Reactors: Decontamination by Thermochemical Methods

Graphite samples from blocks and sleeves are characterized by extremely heterogeneous spatial distribution of radionuclides on the scale of tens and hundreds of micrometers. The graphite decontamination occurs in three steps: Up to 25% of 14C is removed in the course of low-temperature annealing or treatment of graphite with liquid reagents (total weight loss of graphite ≤10%); up to 70–80% of 14C is removed in the course of 20-h heat treatment under oxidizing conditions; and in the final step the degree of removal of 14C exceeds 90%, with a proportional decrease in the graphite weight. Oxidation of graphite in the first steps of thermochemical treatment mainly occurs along (micro)cracks and other defects, which favors the removal of relatively weakly bound 14C, e.g., from the pore space. The removal of 14C from the crystal lattice of graphite requires its breakdown, e.g., by high-temperature heat treatment.

Highly effective impregnation and modification of spruce wood with epoxy-functional siloxane using supercritical carbon dioxide solvent

Chemical modification of wood is an established approach to improve its biological durability, water repellence, dimensional stability, and UV resistance. Norway spruce wood (Picea abies) in dry state, however, has an extraordinarily high recalcitrance towards impregnation with liquid modification reagents as drying triggers the irreversible closure of pits, i.e. the cell-to-cell valves in softwood. In the present study, it is shown that supercritical carbon dioxide is a highly suitable impregnation medium to overcome the recalcitrance of dry spruce wood. This has been exemplarily demonstrated for deca(dimethylsiloxane)-α,ω-diglycidylether (D8M 2 OG ), a linear oligosiloxane with terminal epoxy-functionalities, which could be loaded into respective wood samples affording a weight gain of up to 63%. The thermally assisted reaction of the epoxy-functional siloxane with the wood polymers was catalysed with ring-opening Tin (II) octoate. The effort resulted in a remarkably reduced wettability with water, as evident from contact angle measurements (~ 140°), and in a significant decrease (≤ 20%) of the sample’s sensitivity towards moisture-induced dimensional changes.

Radionuclides in Irradiated Graphite of Uranium–Graphite Reactors: Decontamination of Sleeves Using Liquid Reagents

To examine the possibility of disposal of irradiated graphite in ground near-surface repositories, the concentration and spatial distribution of radionuclides in the volume of irradiated graphite sleeves of industrial uranium–graphite reactors was studied, and the efficiency of decontamination using liquid reagent treatment methods was evaluated. The radionuclide distribution in the graphite volume is extremely heterogeneous on the 10–100 μm scale. The degree of decontamination using solutions with high acid concentrations and fluoride ions added does not exceed 16–25% for 14C and 15–19% for 36Cl. Under these treatment conditions, no structural changes occur in graphite, and 14С bound with the graphite surface via sorption is removed. Significant differences in the efficiency of the reagent decontamination of irradiated graphite from various producers were revealed.

STRECK CELL PRESERVATIVE STABILIZES KOALA ( PHASCOLARCTOS CINEREUS) WHOLE BLOOD FOR COMPLETE BLOOD COUNTS.

Wildlife health assessments at remote sites may lead to delayed testing of whole blood for complete blood counts (CBC) resulting in artifacts affecting clinical interpretation. Streck Cell Preservative (SCP) is a proprietary liquid stabilization reagent designed to preserve human leukocytes and may be applicable to wildlife health assessments when immediate processing of blood is not possible. The purpose of this study was to determine if SCP adequately preserved EDTA-anticoagulated whole blood from koalas ( Phascolarctos cinereus) for up to 14 days. Blood from 12 captive adult koalas was collected and combined with SCP in a 1 : 1 ratio and refrigerated. Paired samples of SCP treated and untreated blood had CBCs performed at five time-points over 14 days. Streck Cell Preservative extended koala EDTA-anticoagulated whole blood viability to 14 days by decreasing cellular lysis. Species- and method-specific reference intervals for SCP should be generated to avoid clinical misinterpretation, especially when evaluating anemia.

Label-free, spatially multiplexed SPR detection of immunoassays on a highly integrated centrifugal Lab-on-a-Disc platform

As a direct, label-free method, Surface Plasmon Resonance (SPR) detection significantly reduces the needs for liquid handling and reagent storage compared to common enzyme-linked immunosorbent assays (ELISAs), thus enabling comprehensive multiplexing of bioassays on microfluidic sample-to-answer systems. This paper describes a highly integrated centrifugal Lab-on-a-Disc (LoaD) platform for automating the full process chain extending between plasma extraction and subsequent aliquoting to five parallelized reaction channels for quantitative SPR detection by an inexpensive smartphone camera. The entire, multi-step / multi-reagent operation completes within less than 1 h. While the emphasis of this work is on the fluidic automation and parallelization by previously introduced, very robust event-triggered valving and buoyancy-driven centripetal pumping schemes, we successfully implement an immunoglobulin G (IgG) assay; by specific functionalization of the detection surfaces, the same disc layout can readily be customised for immunoassays panels from whole blood.

Proficiency Testing for Determination of Water Content in Toluene of Chemical Reagents by iteration robust statistic technique

In order to investigate and improve the level of detection technology of water content in liquid chemical reagents of domestic laboratories, proficiency testing provider PT0031 (CNAS) has organized proficiency testing program of water content in toluene, 48 laboratories from 18 provinces/cities/municipals took part in the PT. This paper introduces the implementation process of proficiency testing for determination of water content in toluene, including sample preparation, homogeneity and stability test, the results of statistics of iteration robust statistic technique and analysis, summarized and analyzed those of the different test standards which are widely used in the laboratories, put forward the technological suggestions for the improvement of the test quality of water content. Satisfactory results were obtained by 43 laboratories, amounting to 89.6% of the total participating laboratories.