Rapid Sample Analysis Research Articles

A flow cytometric method to measure prokaryotic records in ice cores: an example from the West Antarctic Ice Sheet Divide drilling site

ABSTRACTMicroorganisms were the earliest inhabitants on our planet that occupy nearly every environment, and play a major role in biogeochemical cycles. Despite their global importance, there remains a paucity of data on microbial responses to long-term environmental and climatic changes. Microorganisms are known to be immured in glacial ice, but no high-resolution temporal records of their density exist, owing in large part to the lack of appropriate clean methodology that allows for rapid analysis of samples over depth. We describe a clean and time efficient method that can produce a high-temporal resolution record of prokaryotic density archived in ice cores. The method combines acquisition of discrete samples using a continuous ice-core melting system coupled with flow cytometry (FCM) of DNA-stained samples. Specifically, we evaluate the performance of the FCM measurement technique in terms of specificity, precision, accuracy and minimum detection limits. Examples from the West Antarctic Ice Sheet Divide ice core are included to show the efficacy of the method.

A multiplex PCR assay for the detection and quantification of Sclerotinia sclerotiorum and Botrytis cinerea.

Traditional culture methods for identifying the plant fungal pathogens Sclerotinia sclerotiorum (Lib.) de Bary and Botrytis cinerea Pers.:Fr. are slow and laborious. The goal of this study was to develop a multiplex real-time PCR (qPCR) assay to detect and quantify DNA from S.sclerotiorum and B.cinerea. A primer set (SsIGS_5) for S.sclerotiorum was designed that targeted the intergenic spacer (IGS) regions of the ribosomal DNA. Addition of a probe to the assay increased its specificity: when the primer/probe set was tested against 21 fungal species (35 strains), amplification was detected from all S.sclerotiorum strains and no other species. For qPCR, the SsIGS_5 primer and probe set exhibited a linear range from 7·0ng to 0·07pg target DNA (R(2) =0·99). SsIGS_5 was then multiplexed with a previously published primer/probe set for B.cinerea to develop a high-throughput method for the detection and quantification of DNA from both pathogens. When multiplexed, the sensitivity and specificity of both assays were not different from individual qPCR reactions. The multiplex assay is currently being used to detect and quantify S.sclerotiorum and B.cinerea DNA from aerosol samples collected in commercial seed alfalfa fields. A primer and probe set for the quantification of Sclerotinia sclerotiorum DNA in a PCR assay was developed. The probe-based nature of this assay signifies an improvement over previous assays for this species by allowing multiplex reactions while maintaining high sensitivity. The primer/probe set was used in a multiplex real-time PCR assay for the quantification of S.sclerotiorum and Botrytis cinerea DNA, enabling rapid analysis of environmental samples. In crops susceptible to both pathogens, this multiplex assay can be used to quickly quantify the presence of each pathogen.

Sequential determination of trace 4-aminoazobenzene in multiple textiles based on nanoarrayed functionalized polystyrene substrate by surface enhanced Raman spectroscopy

Achieving reproducible signals is a key point to improve the analytical precision and accuracy of surface enhanced Raman scattering (SERS) technique and further expand the application scope of SERS for on-site and rapid analysis of real sample with complex matrice. In this work, a novel Au@hydroxyl-functionalized polystyrene (Au@PS-OH) substrate was prepared by atom transfer radical polymerization and chemical assembly method, which possessed promised potential for the rapid and sequential analysis of multisamples coupling with SERS technique. Au@PS-OH substrate with regular nanoarrayed morphology possessed excellent anti-agglomeration capability even for testing solutions with strong basicity or acidity, mechanic and chemical stability due to the large amount of Au nanoparticles homogeneously and stably fixed on substrate surface. Moreover, excellent hydrophobicity of Au@PS-OH substrate could keep testing droplets of multiple samples stable and uniform spherical shape with similar contact angles to substrate, which guaranteed the reproducible SERS light paths and SERS signals during real sequential analysis. Then, an Au@PS-OH based SERS analytical method was developed and practically applied for the sequential determination of trace 4-aminoazobenzene in various textiles. It was satisfactory that the contents of trace 4-aminoazobenzene in black woolen, green woolen and yellow fiber cloth could be actually found and calculated to be 106.4, 120.9 and 140.8mg/kg with good recoveries of 76.0-118.9% and relative standard deviations of 1.6-5.1%. It is expected that this SERS method is suitable for on-site and rapid analysis of multiple samples in a short period.

State‐of‐the‐art technologies for rapid and high‐throughput sample preparation and analysis of N‐glycans from antibodies

Glycosylation is a PTM that occurs during production of many protein-based biologic drugs and can have a profound impact on their biological, clinical, and pharmacological properties. Quality by design, process optimization, and advance in manufacturing technology create a demand for robust, sensitive, and accurate profiling and quantification of antibody glycosylation. Potential drawbacks in antibody glycosylation profiling include the high hands-on time required for sample preparation and several hours for data acquisition and analysis. Rapid and high-throughput (HTP) N-glycan profiling and characterization along with automation for sample preparation and analysis are essential for extensive antibody glycosylation analysis due to the substantial improvement of turnaround time. The first part of this review article will focus on the recent progress in rapid and HTP sample preparation and analysis of antibody glycosylation. Subsequently, the article will cover a brief overview of various separation and mass spectrometric methods for the rapid and HTP analysis of N-glycans in antibodies. Finally, we will discuss the recent developments in process analytical technologies for the screening and quantification of N-glycans in antibodies.

DART – LTQ ORBITRAP as an expedient tool for the identification of synthetic cannabinoids

Synthetic cannabinoids as designer drugs constitute a major problem due to their rapid increase in number and the difficulties connected with their identification in complex mixtures. DART (Direct Analysis in Real Time) has emerged as an advantageous tool for the direct and rapid analysis of complex samples by mass spectrometry. Here we report on the identification of six synthetic cannabinoids originating from seized material in various matrices, employing the combination of ambient pressure ion source DART and hybrid ion trap - LTQ ORBITRAP mass spectrometer. This report also describes the sampling techniques for the provided herbal material containing the cannabinoids, either directly as plant parts or as an extract in methanol and their influence on the outcome of the analysis. The high resolution mass spectra supplied by the LTQ ORBITRAP instrument allowed for an unambiguous assignment of target compounds. The utilized instrumental coupling proved to be a convenient way for the identification of synthetic cannabinoids in real-world samples.

Novel Laser Ablation Sampling Device for the Rapid Radiocarbon Analysis of Carbonate Samples by Accelerator Mass Spectrometry

AbstractConventional radiocarbon analysis of carbonate records with accelerator mass spectrometry (AMS) is time consuming and the achievable spatial resolution is limited, because individual samples have to be taken and need to be converted to graphite for the measurement. A new laser ablation (LA) in situ sampling technique for rapid online 14C analyses of carbonate records by AMS is presented. By focusing a 193-nm ArF excimer laser on carbonate samples, carbon dioxide is generated and can directly be introduced into the gas ion source of an AMS. A dedicated LA cell for AMS was constructed in a way that combines rapid gas exchange with the capacity to carry sample specimen with maximum dimensions of 15×2.5×1.5 cm3. With the presented setup, negative carbon ion currents up to 20 µA were achieved. A low 14C background of 0.011±0.002 F14C was observed on 14C-free marble and different standard and reference materials could be well reproduced within errors. The novel technique allows scanning carbonate samples continuously over several cm per hour with achievable measurement precisions of less than 1% for modern samples. This approach allows acquiring highly spatially resolved 14C records at a far higher rate than with any currently available method.

Synchrotron based high throughput screening method for mineral analysis in cereal and pulse grains meal

A rapid high throughput non-destructive method, using an X-ray microprobe beamline (Very Sensitive Elemental and Structural Probe Employing Radiation from Synchrotron, VESPERS, CLS Saskatoon), has been developed to screen multiple minerals in cereal and pulse meals. Starch spiked with commercial mineral standards cocktail at different concentrations was optimized to develop standard curve to determine mineral concentrations in grain meal samples. A grid sample holder to hold 84 samples was built for high precision and rapid analysis of multiple samples. The developed analytical method can be used for quantitative determination of eleven minerals including Ca, Cr, Mn, Fe, Ni, Co, Cu, Zn, Se, Rb and Mo at mgKg−1 or ppm concentrations. Method adaptability was assessed using a cereal crop wheat and pulse crop chickpea grain meal. The method was successfully used for Ca, Mn, Fe, Ni, Cu, Zn, Se, Rb and Mo determination in wheat and chickpea and measurements were cross analyzed using inductively coupled plasma mass spectroscopy ICP-MS technique for the same samples. The method is highly sensitive (sensitivity at ppm level) and can be adapted to analyze mineral concentrations in grain meal from crops of interest. The precise and reproducible high throughput screening method can be used in crop improvement to develop bio-fortified grains with increased mineral concentrations.

Stepped MSAll Relied Transition (SMART): An approach to rapidly determine optimal multiple reaction monitoring mass spectrometry parameters for small molecules

Multiple reaction monitoring (MRM) is a universal approach for quantitative analysis because of its high specificity and sensitivity. Nevertheless, optimization of MRM parameters remains as a time and labor-intensive task particularly in multiplexed quantitative analysis of small molecules in complex mixtures. In this study, we have developed an approach named Stepped MSAll Relied Transition (SMART) to predict the optimal MRM parameters of small molecules. SMART requires firstly a rapid and high-throughput analysis of samples using a Stepped MSAll technique (sMSAll) on a Q-TOF, which consists of serial MSAll events acquired from low CE to gradually stepped-up CE values in a cycle. The optimal CE values can then be determined by comparing the extracted ion chromatograms for the ion pairs of interest among serial scans. The SMART-predicted parameters were found to agree well with the parameters optimized on a triple quadrupole from the same vendor using a mixture of standards. The parameters optimized on a triple quadrupole from a different vendor was also employed for comparison, and found to be linearly correlated with the SMART-predicted parameters, suggesting the potential applications of the SMART approach among different instrumental platforms. This approach was further validated by applying to simultaneous quantification of 31 herbal components in the plasma of rats treated with a herbal prescription. Because the sMSAll acquisition can be accomplished in a single run for multiple components independent of standards, the SMART approach are expected to find its wide application in the multiplexed quantitative analysis of complex mixtures.

Tissue Contraction Force Microscopy for Optimization of Engineered Cardiac Tissue.

We developed a high-throughput screening assay that allows for relative comparison of the twitch force of millimeter-scale gel-based cardiac tissues. This assay is based on principles taken from traction force microscopy and uses fluorescent microspheres embedded in a soft polydimethylsiloxane (PDMS) substrate. A gel-forming cell suspension is simply pipetted onto the PDMS to form hemispherical cardiac tissue samples. Recordings of the fluorescent bead movement during tissue pacing are used to determine the maximum distance that the tissue can displace the elastic PDMS substrate. In this study, fibrin gel hemispheres containing human induced pluripotent stem cell-derived cardiomyocytes were formed on the PDMS and allowed to culture for 9 days. Bead displacement values were measured and compared to direct force measurements to validate the utility of the system. The amplitude of bead displacement correlated with direct force measurements, and the twitch force generated by the tissues was the same in 2 and 4 mg/mL fibrin gels, even though the 2 mg/mL samples visually appear more contractile if the assessment were made on free-floating samples. These results demonstrate the usefulness of this assay as a screening tool that allows for rapid sample preparation, data collection, and analysis in a simple and cost-effective platform.

High-performance liquid chromatography with photodiode array detection and chemometrics method for the analysis of multiple components in the traditional Chinese medicine Shuanghuanglian oral liquid.

Shuanghuanlian oral liquid, a traditional Chinese medicine preparation, is a mixture of three herbs (Flos Lonicerae, Radix Scutellariae and Fructus Forsythiae). In this study, the quantitative analysis of three main active compounds, chlorogenic acid, forsythin and baicalin in samples from different manufacturers was performed rapidly by high-performance liquid chromatography coupled with photodiode array detection followed by Contour Projection coupled to stepwise regression treatment of the obtained three-dimensional spectra in which the partial overlap between adjacent target components existed. The method was validated for linearity (R>0.9940), precision (RSD<1.25%), recovery (92.20-102.50%), limit of detection (0.01-0.02 μg/mL) and limit of quantification (0.03-0.07 μg/mL). The results indicated that the combination of the three-dimensional spectra of traditional Chinese medicine and Contour Projection-stepwise regression offered an accurate, simple, low-cost and eco-friendly way for the rapid quantitative analysis of Shuanghuanlian oral liquid samples.

A direct ionization mass spectrometry-based approach for differentiation of medicinal Ephedra species

Herein, rapid and efficient identification of species of medicinal Ephedrae Herba was performed using DI-MS (direct ionization-mass spectrometry)-based metabolomics analysis. As a direct ionization technique, DI-MS can provide rapid analysis of samples without sample preparation, so it has been advantageously applied to high-throughput metabolomics analysis. In this flow chart, the MS fingerprints of Ephedrae Herba samples obtained by DI-MS method were firstly pretreated by background subtracts, smooth and center procedures to extract MS features. Then, these MS features were aligned using in a house program written in MATLAB to produce MS dataset. After that, PCA and PLS-DA analysis were performed based on the obtained MS dataset. Finally, the parameter VIP (Variable importance in the Projection) was employed to screen the valuable MS features for discrimination. Using such an approach, three medicinal species of Ephedrae Herba, Ephedra sinica, Ephedra intermedia, and Ephedra equisetina., had been successfully differentiated. Additionally, this method has also been applied to identify the changes in components of Ephedrae Herba after honey treated. In present study, DI-MS in combination with metabolomics was shown to be an efficient and accurate way to identify the sources of herbs.

Peltier Heating-Assisted Low Temperature Plasma Ionization for Ambient Mass Spectrometry

Low temperature plasma (LTP) ionization mass spectrometry (MS) is one of the widely used ambient analysis methods which allows soft-ionization and rapid analysis of samples in ambient condition with minimal or no sample preparation. One of the major advantages of LTP MS is selective analysis of low-molecular weight, volatile and low- to medium-polarity analytes in a sam- ple. On the contrary, the selectivity for particular class of compound also implies its limitation in general analysis. One of the critical factors limiting LTP ionization efficiency is poor desorption of analytes with low volatility. In this study, a home-built LTP ioniza- tion source with Peltier heating sample stage was constructed to enhance desorption and ionization efficiencies of analytes in a sam- ple and its performance was evaluated using standard mixture containing fatty acid ethyl esters (FAEEs). It was also used to reproduce the previous bacterial identification experiment using pattern-recognition for FAEEs. Our result indicates, however, that the bacterial differentiation from FAEE pattern recognition using LTP ionization MS still has many limitations.

Point-of-care testing of electrolytes and calcium using blood gas analysers: it is time we trusted the results

BackgroundPoint-of-care testing allows rapid analysis of samples to facilitate prompt clinical decisions. Electrolyte and calcium abnormalities are common in acutely ill patients and can be associated with life-threatening consequences. There...

Highly sensitive on-site detection of drugs adulterated in botanical dietary supplements using thin layer chromatography combined with dynamic surface enhanced Raman spectroscopy

The phenomenon of botanical dietary supplements (BDS) doped with illegal adulterants has become a serious problem all over the world, which could cause great threat to human’s health. Therefore, it is of great value to identify BDS. Herein, we put forward a highly sensitive method for on-site detection of antitussive and antiasthmatic drugs adulterated in BDS using thin layer chromatography (TLC) combined with dynamic surface enhanced Raman spectroscopy (DSERS). Adulterants in BDS were separated on a TLC plate and located under UV illumination. Then DSERS detection was performed using a portable Raman spectrometer with 50% glycerol silver colloid serving as DSERS active substrate. Here, the effects of different solvents on detection efficacy were evaluated using phenformin hydrochloride (PHE) as a probe. It was shown that 50% glycerol resulted in higher SERS enhancement and relatively higher stability. Moreover, practical application of this novel TLC–DSERS method was demonstrated with rapid analysis of real BDS samples and one sample adulterated with benproperine phosphate (BEN) was found. Furthermore, the obtained result was verified by ultra performance liquid chromatography-quadrupole time of flight mass spectrometry (UPLC–QTOF/MS). The sensitivity of the TLC–DSERS technique is 1–2 orders of magnitude higher than that of TLC–SERS technique. The results turned out that this combined method would have good prospects for on-site and sensitive detection of adulterated BDS.

A highly-efficient imprinted magnetic nanoparticle for selective separation and detection of 17β-estradiol in milk

In this work, we prepared molecularly imprinted polymers (MIPs) combining surface molecular imprinting technique and magnetic separation for separation and determination of 17β-estradiol (E2) from milk. During the synthesis process, the acryloyl chloride was specially used to graft double bonds on Fe3O4 nanoparticles and served as co-functional monomer cooperating with acrylamide. The morphology, structure property, and the best polymerization and adsorption conditions of the prepared magnetic nanoparticles were investigated in detail. The obtained nanomaterials displayed high adsorption capacity of 12.62mg/g, fast equilibrium time of 10min, and satisfactory selectivity for target molecule. What’s more, the MIPs was successfully applied as sorbents to specifically separate and enrich E2 from milk with a relatively high recovery (88.9–92.1%), demonstrating the potential application of the MIPs as solid phase extractant for rapid, highly-efficient, and cost-effective sample analysis.

Determination of oil and oil products total content in soils for monitoring of contamination and effectiveness of remediation

The method of determining the content of oil and petroleum products in the soils is substantiated through the use established by thermogravimetric curves optimum temperatures and time intervals thermal sample of contaminated soil, determination of total losses its weight on the appropriate formula which ensures the quantitative determination of total content level of hydrocarbons of oil and oil products in the soil with increased accuracy and quick testing of the method. In the methodical approach by combining individual components of the known methods thermogravimetry and gas chromatography, the distribution regularities of changes in the sample mass under the influence of thermal effects on a new class of objects with simultaneous production of a rapid method for determination of total content of petroleum hydrocarbons in soils, provided simplification soil samples algorithm analyzing for pollution monitoring and the remediation effectiveness of obtaining the economic use of resources. The invention belongs to the field of environmental protection, soil quality, namely to the ways of determine the content of oil and petroleum products (diesel, kerosene, fuel oil, etc.) in contaminated soils while of soils lands plot monitoring. The method can be used in the field of conservancy in the oil industrial complex in determining the degree of contamination of soil for rapid analysis of soil samples; in agroecology, soil ecological management for environmental monitoring of technologically contaminated soils of lands plots for various purposes and their using; in research practice - to investigate the thermal processes and properties of soils; elaboration of scientific and methodical bases of contaminated soils monitoring (diagnosis, assessment, forecast ecological state), environmental regulation of organic nature contaminants in soils; regulation of the using and soil remediation processes to improve quality. Based on the analysis of the scientific literature data and results of long-term experiments it was determined the optimal temperature range of 280–500 ○C with different temperature ranges of thermal evaporation the fractions of petroleum hydrocarbons. Series conducted modeling experiments with varying temperature, time, sample the soils and the changing quantitative and qualitative composition of hydrocarbons in contaminated soils, the total petroleum hydrocarbons thermogravimetric method has been found that the thermal degradation of contaminated soils samples formed various fractions of hydrocarbons, which leads to increased losses mass Dm contaminated soil sample to obtain thermogravimetric curves. By the method of gas chromatography, in the range of 100–200 ○C it is set the selective extraction of lighter fractions of petroleum and petroleum products in the soil; in the range of 280–350 ○C – it is noted a sharp increase in the rate of decomposition of oil saturated hydrocarbons (C10–C40) with intensive gas evolution, the formation of a mixture of reaction products is a significant amount of unsaturated hydrocarbons. Thus, the use of established ranges of determining the optimum temperature desorption fractions of petroleum hydrocarbons and their thermal degradation of soil samples for thermolysis with simultaneous identification of the total content of oil and petroleum products in the soil, it is possible to determine the total amount of oil hydrocarbons fractions in soil as the amount of oil hydrocarbons. The proposed algorithm method is suitable for the soils of different genesis. It is determined that the consistent increase in temperature is a necessary procedure for the identification of pollution if soil sample analysis of the expected low concentrations of oil and petroleum products and water content in soils of different types and different size distribution of more than 5 % of oil production zones. By evaluating the flow of thermal processes in the surveyed contaminated and uncontaminated soil samples the temperature ranges degradation of petroleum hydrocarbons is determined. Their using, as an indicator, significantly reduced the timing of selection of optimal technological parameters of thermal oils in the soils for determining the total content of oil and petroleum products in the soils, pollution monitoring and remediation efficiency control.

AUTOMATED GATING OF PORTABLE CYTOMETER DATA BASED ON SKEW t MIXTURE MODELS

A major component of flow cytometry (FCM) data analysis involves gating, which is the process of identifying homogeneous groups of cells. With the rapid development of the portable flow cytometer, manual gating techniques have been unable to meet the demand for accurate and rapid analysis of samples. To provide a practical application for portable devices, we propose a flexible, statistical model-based clustering approach for identifying cell populations in FCM data. This approach, which mimics the manual gating process, employs a finite mixture model with a density function of skew t distribution and estimates parameters via an expectation maximization algorithm. Data analysis from an experiment on a patient’s peripheral blood samples have proven that the proposed methodology yields better results in terms of robustness against outliers than current state-of-the-art automated gating methods, has more flexibility in clustering symmetric data and leads to lower misclassification rates (misclassification rates of skew t method is 0.06442) when handling highly asymmetric data. The method we proposed will improve data analysis of portable flow cytometers, especially when the users have no professional training.

Use of liquid chromatography methods for rapid analysis and evaluation of quality of UP-637 epoxy-resorcinol resin

Data on rapid analysis of industrial samples of UP-637 epoxy-resorcinol resin by reversed-phase high-performance liquid chromatography and gel permeation chromatography are reported. The results obtained by chromatographic and analytical methods well correlate with each other. The advantages of chromatographic methods are short analysis time and the possibility of estimating the content of side components and evaluating the technology used for the resin synthesis. Nevertheless, wide use of the suggested procedures requires their additional trials.

Analysis of phytoplankton distribution and community structure in the German Bight with respect to the different size classes

Investigation of phytoplankton biodiversity, ecology, and biogeography is crucial for understanding marine ecosystems. Research is often carried out on the basis of microscopic observations, but due to the limitations of this approach regarding detection and identification of picophytoplankton (0.2–2μm) and nanophytoplankton (2–20μm), these investigations are mainly focused on the microphytoplankton (20–200μm). In the last decades, various methods based on optical and molecular biological approaches have evolved which enable a more rapid and convenient analysis of phytoplankton samples and a more detailed assessment of small phytoplankton. In this study, a selection of these methods (in situ fluorescence, flow cytometry, genetic fingerprinting, and DNA microarray) was placed in complement to light microscopy and HPLC-based pigment analysis to investigate both biomass distribution and community structure of phytoplankton. As far as possible, the size classes were analyzed separately. Investigations were carried out on six cruises in the German Bight in 2010 and 2011 to analyze both spatial and seasonal variability.Microphytoplankton was identified as the major contributor to biomass in all seasons, followed by the nanophytoplankton. Generally, biomass distribution was patchy, but the overall contribution of small phytoplankton was higher in offshore areas and also in areas exhibiting higher turbidity. Regarding temporal development of the community, differences between the small phytoplankton community and the microphytoplankton were found. The latter exhibited a seasonal pattern regarding number of taxa present, alpha- and beta-diversity, and community structure, while for the nano- and especially the picophytoplankton, a general shift in the community between both years was observable without seasonality. Although the reason for this shift remains unclear, the results imply a different response of large and small phytoplankton to environmental influences.

Humidity independent mass spectrometry for gas phase chemical analysis via ambient proton transfer reaction

In this work, a humidity independent mass spectrometric method was developed for rapid analysis of gas phase chemicals. This method is based upon ambient proton transfer reaction between gas phase chemicals and charged water droplets, in a reaction chamber with nearly saturate humidity under atmospheric pressure. The humidity independent nature enables direct and rapid analysis of raw gas phase samples, avoiding time- and sample-consuming sample pretreatments in conventional mass spectrometry methods to control sample humidity. Acetone, benzene, toluene, ethylbenzene and meta-xylene were used to evaluate the analytical performance of present method. The limits of detection for benzene, toluene, ethylbenzene and meta-xylene are in the range of ∼0.1 to ∼0.3ppbV; that of benzene is well below the present European Union permissible exposure limit for benzene vapor (5μgm−3, ∼1.44ppbV), with linear ranges of approximately two orders of magnitude. The majority of the homemade device contains a stainless steel tube as reaction chamber and an ultrasonic humidifier as the source of charged water droplets, which makes this cheap device easy to assemble and facile to operate. In addition, potential application of this method was illustrated by the real time identification of raw gas phase chemicals released from plants at different physiological stages.