Capillary Probe Research Articles

Comparative study of erythrocyte sedimentation rate measurement between Celltac Alpha+ (MEK-1305) ESR Analyzer and standard Westergren method

Background: The Westergren method, a gold standard method for erythrocyte sedimentation rate (ESR) measurement, is one of the screening tests for routine clinical hematology that can be used as an inflammation marker. Since the results can be altered by numerous factors, new methodologies have been established to manage the possible pitfalls. Objective: This study compared erythrocyte sedimentation rate measurements obtained by the Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer with those obtained by the standard Westergren method. Materials and methods: The Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer was used to assess the performance of ESR measurement compared to the standard Westergren method. A total of 220 random EDTA whole blood samples from patients were included and analyzed in parallel using the automated analyzer and the standard Westergren method. Results: Spearman’s rank correlation coefficient (ρ = 0.916) obtained a good correlation between the two methods. In addition, the precision was good and acceptable according to the criteria, with a %CV of less than 10% in both intra-run and inter-run precision. There was no contamination between blood samples from using a single capillary probe. Moreover, Bland-Altman mean difference plot also indicated a good agreement, with a mean bias of -1.4 (95% CI: -0.8 to 2.1), an upper LOA of 7.6 (95% CI: 6.6 to 8.7) and a lower LOA = -10.5 (95% CI: -11.6 to -9.5). Conclusion: This comparative study indicated that the Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer is applicable within clinical routine practice along with proper measurement regulation. Even though the principles between these two methods are completely different, an acceptable interrelation was obtained due to the calibration process by Nihon Kohden corporation.

Probe oscillation control in tapping-mode scanning probe electrospray ionization for stabilization of mass spectrometry imaging.

Mass spectrometry imaging (MSI) is used for visualizing the distribution of components in solid samples, such as biological tissues, and requires a technique to ionize the components from local areas of the sample. Tapping-mode scanning probe electrospray ionization (t-SPESI) uses an oscillating capillary probe to extract components from a local area of a sample with a small volume of solvent and to perform electrospray ionization of those components at high speed. MSI can be conducted by scanning the sample surface with a capillary probe. To ensure stable extraction and ionization for MSI, the probe oscillation during measurements must be understood. In this study, we examined the changes in oscillation amplitude and phase due to the interaction between the oscillating probe and the brain tissue section when the probe tip was dynamically brought close to the sample surface. The changes in the probe oscillation depended on the oscillation frequency and polarity of the bias voltage applied to the solvent because an electrostatic force shifted the frequency of the probe oscillation. These findings suggest that controlling the probe oscillation frequency is important for stabilizing MSI by t-SPESI.

Design and development of cost-effective fiber Bragg grating temperature sensor package

A cost-effective fiber Bragg grating (FBG) temperature sensor package was designed and developed with two distinct sensing probes and demodulation schemes. U-shaped and capillary shape probes were designed and tested using an optical spectrum analyzer and two different indiginously developed intensity demodulation schemes. The temperature sensitivities were measured as 12.94 ± 0.15 pm °C−1, 11.57 ± 0.12 pm °C−1, and 12.03 ± 0.14 pm °C−1 for a bare FBG and for FBGs encapsulated in the U-shaped and capillary probes, respectively, with negligible hysteresis and a repeatability of 1 °C–3 °C. The performance of the probes was demonstrated by twin-FBG intensity demodulation schemes, the range of which was increased up to 181.50 °C with a resolution of 0.120 °C by the development of a CFBG-FBG intensity demodulation scheme.

Levels of Radon in Soils of Dodoma City, Central Tanzania

Purpose: Humans receive radiation doses exceeding fifty percent (50%) of the total dose from natural sources as a result of inhaling radon and thoron gases and their daughters. Radon occurs naturally in soils and can diffuse into indoor environments leading to adverse health effects for inhabitants. In this study, measurement of levels of radon gas in soils was performed with the purpose of categorizing areas and highlighting the likelihood of high levels of radon in indoor environments.
 Design/Methodology/ Approach: The study targeted the environs of Dodoma where the rapid expansion of human settlements is ongoing or anticipated. For easy access and convenience, the study was conducted in areas located along main roads leading to the nearby towns/cities. Sampling was done by inserting the drilling rod to a depth of approximately one meter (1 m) below ground level with the aid of a heavy hammer. The alpha pump was used to suck the soil gas from the ground through a metallic tube (the capillary probe) and pressed it into the ionization chamber of the measuring instrument (AlphaGUARD). Radon concentration was read directly from the instrument’s display.
 Findings: It was found that radon concentrations in soil vary from 18.8 to 233.5 kBq.m-3. Based on the radon risk criterion, surveyed areas range from normal to high radon risk categories.
 Research Limitation/Implication: The study only covered a limited area in Dodoma City, and therefore the results may not be representative of the entire city or even the surrounding regions.
 Practical Implications: This study is useful in categorizing building areas based on radon risk criterion with the purpose of reducing possibilities of radon-related health risks; mainly lung cancer to the population.
 Social Implications: Radon is a proven cause of lung cancer in humans. Therefore, knowledge of radon levels in the study area will help in setting the mitigation measures necessary for public health protection.
 Originality / Value/ Novelty: The study demonstrates an approach for estimating radon levels in soils which is beneficial to current and future researchers, environmentalists and regulators, among others.

Automotive Diesel Fuel Internal Stability Testing with the Use of UV and Temperature as Degradation Factors

Diesel fuel stability can be considered from many points of view, of which the two considered most important are stability in contact with the environment and internal stability. Fuel stability in touch with the environment is often defined as oxidation stability, of which measurement procedures are well developed. The presented paper shows that fuel's internal stability can also be important. The internal stability of diesel fuel with the local use of thermal and ultraviolet radiation (UV) as degradation factors and fluorescence signals as a probe is presented in this paper. We show that the internal degradation of fuel with temperature use differs from that with UV and simultaneous both factors use. Our study shows that using temperature as a degradation factor introduces significant fluorescence fading. Moreover, the fluorescence signal restores significantly later than the sample stabilizes at room temperature. The novelty proposed based on examination is hybrid degradation and an examination cycle that enables the simultaneous use of degradation factors and fluorescence reading. For this purpose, a dedicated measurement setup of signal control and processing was constructed and programmed. The measurement procedure of the data series for specific wavelength enables calculation of signal shifts that allow the internal stability classification of diesel fuel samples in less than 30 min with the cost of a single disposable capillary probe and one polymer plug. Premium and regular fuel examination results show that internal fuel stability can be related to polycyclic aromatic hydrocarbons (PAH) concentrations and can be modified with dedicated additives.

Capillary Bridges on Hydrophobic Surfaces: Analytical Contact Angle Determination.

The capillary bridge probe method was introduced previously as a high-accuracy contact angle determination method relying on capillary bridges on hydrophilic and superhydrophilic surfaces [Nagy, N. Langmuir2019, 35 ( (15), ), 5202−521230916567]. In this work, the behavior of r-ϑ type liquid bridges was studied and the contact angles were determined on hydrophobic surfaces. The equilibrium shape of these liquid bridges often does not contain the neck or haunch region. The unknown neck/haunch radius prevents analytical evaluation of the capillary bridge shape. In this work, the possible incomplete liquid bridge shapes were classified and a novel procedure was developed for the Delaunay’s analytical solution-based evaluation of these states. The parameter space of the capillary bridges was visualized and described without using dimensionless variables. As a demonstration, Cyclo Olefin Polymer and PTFE surfaces were investigated, with advancing and receding contact angles determined and compared to the results of sessile drop measurements.

Measuring in-situ capillary pressure of a flowing foam system in porous media

HypothesisCapillary pressure (Pc) is an intrinsic property of aqueous foams that has been demonstrated to play an important role in lamella rupture. Thus, directly measuring in-situ capillary pressure of a foam flowing through porous media has potential to greatly improve understanding of this complex process. ExperimentsA capillary pressure probe was constructed and validated. Direct measurements of capillary pressure were made at ambient conditions during foam quality scan experiments in a transparent 1.41 × 10−10 m2 (143-Darcy) homogenous sand pack conducted at constant gas velocity. The foam texture was simultaneously visualized at the wall of the sand pack via microscope. FindingsIn the low-quality regime, a plateauing trend in Pc was identified. In-situ microscopic visualization of the flowing foam revealed that gas bubbles were convecting with a fine discontinuous texture while Pc is at the plateau value Pcp. In the high-quality regime, the measured capillary pressures first decreased with increasing quality before increasing again at the driest qualities. These changes in Pc correlated with foam bubbles becoming coarser with increasing injected gas fractional flow before transitioning to continuous-gas flow at the slowest and driest injection conditions. These findings have been previously unreported for steady-state flow conditions and shall have significant implications for the general physical description of foam flow in porous media.

A simultaneous dual-polarity mass spectrometer with electron start for MeV-SIMS

The Capillary Heavy Ion MeV-SIMS Probe (CHIMP) at ETH Zürich has been redesigned with a second mass spectrometer and symmetric extraction to enable simultaneous analysis of positive and negative secondary ions. Secondary electrons are deflected within the negative spectrometer and detected independently. The fast secondary electron signal is used as a start signal for both Time-of-Flight mass spectrometers.The new setup enables the simultaneous acquisition and analysis of both secondary ion polarities emitted under identical conditions from the same sample location. This allows to study correlations between secondary ions of different polarities emitted from a single primary ion impact. Measurements with small primary Cn cluster ions show the influence of cluster size on the multiplicity of secondary ion emission. Furthermore, a cluster effect in the ratio between positive and negative ion yields of corresponding secondary ion species is identified, with the ratio approaching parity for larger cluster sizes n.

Reflective fiber-optic magnetic field sensor based on a magnetic-fluid-filled capillary probe structure

A novel reflective magnetic field sensor is presented and experimentally demonstrated. The sensing probe is fabricated by splicing a section of uncoated four-core fiber (FCF) between two sections of no-core fibers (NCFs), and the end face of the last NCF is coated by silver. The sensor structure is sealed in a magnetic fluid (MF)-filled capillary, so that the NCF–FCF–NCF magnetic field sensing probe structure is obtained. The NCF is used to excite the high-order modes of the FCF’s cladding. Combined with the adjustable refractive index of MF, the sensor is sensitive to the magnetic field and temperature. Experimental results indicate that the presented sensor can measure the low magnetic field and high magnetic field. In the low magnetic field ranges of 0–10 mT and 10–18 mT, the wavelength near 1548 nm varies linearly with the magnetic field intensity, and the sensitivities are −7.43 pm mT−1 and −60 pm mT−1, respectively. The sensitivity of the interference intensity is −0.30782 dB mT−1 in the low magnetic field intensity range of 0–18 mT. The sensor under low magnetic field is also affected by temperature. In the temperature range of 20 °C–70 °C, the temperature sensitivity of the wavelength shift around 1548 nm is 62.33 pm °C−1, and the corresponding sensitivities of the interference intensity are −0.03888 dB °C−1 and −0.02076 dB °C−1 in the range of 30 °C–50 °C and 50 °C–70 °C, respectively. However, the effect of temperature on the sensor in the high magnetic field (18–36 mT) can be ignored. Within the high magnetic field intensity range of 26–36 mT, the sensitivity of the interference intensity near 1598 nm is −1.20993 dB mT−1. The dual-parameter matrix is used to eliminate the cross-sensitivity of temperature in the low magnetic field. This sensor, with the advantages of easy fabrication, high sensitivity and low cost, has the potential application in the magnetic field monitoring.

High-Spatial-Resolution Multimodal Imaging by Tapping-Mode Scanning Probe Electrospray Ionization with Feedback Control.

Direct extraction and ionization techniques using minute amounts of solvent can be employed for the rapid analysis of chemical components in a sample without any sample preparation steps. This type of approach is important for mass spectrometry imaging of samples with multiple chemical components that have different spatial distributions (i.e., biological tissues). To improve the spatial resolution of such imaging, it is necessary to reduce the solvent volume for extraction and deliver it to the sample surface. This report describes a feedback control system applied to tapping-mode scanning probe electrospray ionization. By combining the measurement technique of capillary probe vibration with the dynamic distance control system between the probe and the sample, the vibration amplitude of the probe is maintained while the probe scans over uneven samples. This method allows simultaneous high-resolution imaging of molecular distribution, surface topography, and amplitude/phase changes in the probe vibration. Such multimodal imaging is demonstrated on rhodamine B thin films in microwells and on a mouse brain tissue section. This technique can generally be applied to examine the multidimensional molecular distribution and the surface profiles of various objects.

A flexible and cost-effective manual droplet operation platform for miniaturized cell assays and single cell analysis

Herein, we developed a flexible and cost-effective manual droplet operation system (MDOS) for performing miniaturized cell assays as well as single cell analysis. The MDOS consists of a manual x-y-z translation stage for liquid transferring and switching, a high-precision syringe pump for liquid driving and metering, a tapered capillary probe for droplet manipulation, a droplet array chip for droplet loading and reaction, sample/reagent reservoirs for storage, and a microscope for droplet observation, with a total expense of only $4,000. By using the flexible combination of three elementary operations of the x-y-z stage's moving and the pump's aspirating and depositing, the MDOS can manually achieve multiple droplet handling operations in the nanoliter to picoliter range, including droplet generation, assembling, fusion, diluting, and splitting. On this basis, multiple cell-related operations could be performed, such as nanoliter-scale in-droplet cell culture, cell coculture, drug stimulation, cell washing, and cell staining, as well as formation of picoliter single-cell droplets. The feasibility and flexibility of the MDOS was demonstrated in multi-mode miniaturized cell assays, including cell-based drug test, first-pass effect assay, and single-cell enzyme assay. The MDOS with the features of low cost, easy to build and flexible to use, could provide a promising alternative for performing miniaturized assays in routine laboratories, in addition to conventional microfluidic chip-based systems and automated robot systems.

Direct analysis of naphthenic acids in constructed wetland samples by condensed phase membrane introduction mass spectrometry.

The application of direct mass spectrometry techniques to the analysis of complex samples has a number of advantages including reduced sample handling, higher sample throughput, in situ process monitoring, and the potential for adaptation to on-site analysis. We report the application of a semi-permeable capillary hollow fibre membrane probe (immersed directly into an aqueous sample) coupled to a triple quadrupole mass spectrometer by a continuously flowing methanol acceptor phase for the rapid analysis of naphthenic acids with unit mass resolution. The intensity of the naphthenic acid-associated peaks in the mass spectrum are normalized to an internal standard in the acceptor phase for quantitation and the relative abundance of the peaks in the mass spectrum are employed to monitor compositional changes in the naphthenic acid mixture using principle component analysis. We demonstrate the direct analysis of a synthetic oil sands process-affected water for classical naphthenic acids (CnH2n+zO2) as they are attenuated through constructed wetlands containing sedge (Carex aquatilis), cattail (Typha latifolia), or bulrush (Schoenoplectus acutus). Quantitative results for on-line membrane sampling compare favourably to those obtained by solid-phase extraction high-resolution mass spectrometry. Additionally, chemometric analysis of the mass spectra indicates a clear discrimination between naphthenic acid-influenced and natural background waters. Furthermore, the compositional changes within complex naphthenic acid mixtures track closely with the degree of attenuation. Overall, the technique is successful in following changes in both the concentration and composition of naphthenic acids from synthetic oil sands process-affected waters, with the potential for high throughput screening and environmental forensics.

Identification of Porphyrin-Silica Composite Nanoparticles using Atmospheric Solids Analysis Probe Mass Spectrometry

ABSTRACTPorphyrins are vital pigments involved in biological energy transduction processes. Their abilities to absorb light, then convert it to energy, have raised the interest of using porphyrin nanoparticles as photosensitizers in photodynamic therapy. A recent study showed that self- assembled porphyrin-silica composite nanoparticles can selectively destroy tumor cells, but detection of the cellular uptake of porphyrin-silica composite nanoparticles was limited to imaging microscopy. Here we developed a novel method to rapidly identify porphyrin-silica composite nanoparticles using Atmospheric Solids Analysis Probe-Mass Spectrometry (ASAP-MS). ASAP-MS can directly analyze complex mixtures without the need for sample preparation. Porphyrin-silica composite nanoparticles were vaporized using heated nitrogen desolvation gas, and their thermo-profiles were examined to identify distinct mass- to-charge (M/Z) signatures. HeLa cells were incubated in growth media containing the nanoparticles, and after sufficient washing to remove residual nanoparticles, the cell suspension was loaded onto the end of ASAP glass capillary probe. Upon heating, HeLa cells were degraded and porphyrin-silica composite nanoparticles were released. Vaporized nanoparticles were ionized and detected by MS. The cellular uptake of porphyrin-silica composite nanoparticles was identified using this ASAP-MS method.

Correction to: A Galinstan-Filled Capillary Probe for Thermal Conductivity Measurements and Its Application to Molten Eutectic KNO3–NaNO3–NaNO2 (HTS) up to 700 K

The original version of the article unfortunately contained an error in article title. The last compound in the chemical formula should be “NaNO2” instead of “NO2”. The corrected article title is given below.

Capillary Sensor with Disposable Optrode for Diesel Fuel Quality Testing.

Diesel fuel quality can be considered from many different points of view. Fuel producers, fuel consumers, and ecologists have their own ideas. In this paper, a sensor of diesel fuel quality type, and fuel condition that is oriented to the fuel’s consumers, is presented. The fuel quality types include premium, standard, and full bio-diesel classes. The fuel conditions include fuel fit for use and fuel degraded classes. The classes of fuel are connected with characteristics of engine operation. The presented sensor uses signal processing of an optoelectronic device monitoring fuel samples that are locally heated to the first step of boiling. Compared to previous works which consider diesel fuel quality sensing with disposable optrodes which use a more complex construction, the sensor now consists only of a capillary probe and advanced signal processing. The signal processing addresses automatic conversion of the data series to form a data pattern, estimates the measurement uncertainty, eliminates outlier data, and determines the fuel quality with an intelligent artificial neural network classifier. The sensor allows the quality classification of different unknown diesel fuel samples in less than a few minutes with the measurement costs of a single disposable capillary probe and two plugs.

Visualization of Sampling and Ionization Processes in Scanning Probe Electrospray Ionization Mass Spectrometry.

Ambient sampling and ionization techniques based on direct liquid extraction and electrospray ionization are of great value for rapid analysis and mass spectrometry imaging. Scanning probe electrospray ionization (SPESI) enables the sampling and ionization of analyte molecules in a solid material using a liquid bridge and electrospray, respectively, from a single capillary probe. To further improve SPESI, it is essential to understand the dynamic behavior of nanoliter volumes of liquids during sampling and ionization. In this study, the dynamic formation and breakage of the liquid bridge and the subsequent electrospray ionization were investigated by measuring the displacement of the capillary probe using a new optical technique. Measurements revealed that both the time from the formation of the liquid bridge to its breakage and the time from the breakage of the liquid bridge to the detection of analyte ions were correlated with the physical properties of the solvent. It was also found that both of these times were positively correlated with the flow rate. These results will not only lead to the improvement of sampling and ionization efficiencies but also afford a greater understanding of the physicochemical properties of charged nanoliter volumes of liquids.

Coated direct inlet probe coupled with atmospheric-pressure chemical ionization and high-resolution mass spectrometry for fast quantitation of target analytes

The coated direct inlet probe (CDIP) is a new laboratory-made low-cost technology developed from a direct inlet probe (DIP), which has the advantage of quick enrichment/cleanup of an analyte from liquid samples. A capillary probe is coated with hydroxy-terminated polydimethylsiloxane (OH-PDMS), divinylbenzene (DVB), and β-cyclodextrin (β-CD) by a sol-gel method. This probe can be directly coupled with a commercialized atmospheric-pressure chemical ionization (APCI) ion source and high-resolution mass spectrometry, which are widely applicable, reliable, and durable. The ability to perform quantitative analyses with the use of a stable-isotope-labeled internal standard (SIL-IS) was tested by using different concentrations of acenaphthylene (ACY), acenaphthene (ACP), fluorene (FLR), fluoranthene (FLT), phenanthrene (PHE), and benzo[a]pyrene (B[a]P). Calibration curves with a coefficient of determination of R2 ≥ 0.9982 for different polycyclic aromatic hydrocarbons (PAHs) were obtained. A limit of detection (LOD) of 0.008–0.04 ng mL−1 for PAHs was determined. The entire workflow is solvent-free and can be completed in less than 5 min, which demonstrates the advantages of this technique for quantitative analysis.

Specific Features of Corrosion and the Microelectrochemical Heterogeneity of 45 and U8 Steels in Hydrogen-Sulfide Media

We analyze the character of corrosion of 45 and U8 steels with ferrite–pearlite (pearlite), sorbite, troostite, and martensite structures in hydrogen-sulfide media. It is shown that, as a result of hydrogen-sulfide corrosion, sulfide-containing films are formed on their surface. It is established that the degree of localization of pits and the depth corrosion indices depend on the structures of steels and their grades. Corrosion pits develop most intensely on the surfaces of steels with martensite (U8 steel) and troostite (45 steel) structures. We analyze the microelectrochemical heterogeneity of the surfaces of these steels prior to and after hydrogen-sulfide corrosion by the method of scanning with a capillary probe in a moving drop of an МЕХ aqueous solution. It is shown that, for 45 steel with troostite structure, it increases by a factor of ∼ 7. The local potentials take their highest values at the sites of the largest corrosion pits and attain 300 mV.

Particle Measurement Techniques in Fluid Process Engineering

AbstractDroplets, bubbles, or solid particle concentrations and their particle size distributions markedly influence the process conditions. In this article, an overview with respect to popular invasive and non‐invasive local measurement techniques for bubbles and droplets will be given. It starts with capillary suction probes, laser Doppler anemometry and finally covers actual developments in tomography and optical endoscopic measurement techniques. Furthermore, the possibilities and limitations of analyzing particle size distributions with these different methods in various application fields will be discussed.

Development of μ-Low-Flow-Push-Pull Perfusion Probes for Ex Vivo Sampling from Mouse Hippocampal Tissue Slices.

This work demonstrates a reduced tip μ-low-flow-push-pull perfusion technique for ex vivo sampling of the extracellular space of mouse hippocampal brain slices. Concentric fused-silica capillary probes are pulled by an in-house gravity puller with a butane flame producing probe tips averaging an overall outer diameter of 30.3 ± 8 μm. The 10-30 nL/min perfusion flow rate through the probe generates an average recovery of 90%. Sampling was performed with mouse brain tissue slices to characterize basal neurotransmitter content in this model system. Samples were collected from hippocampal tissue slices at a volume of 200 nL per sample. Sample arginine, histamine, lysine, glycine, glutamate, and aspartate content was quantified by micellar electrokinetic chromatography with LED-induced fluorescence detection. Primary amine content was sampled over several hours to determine evidence for tissue damage and loss of extracellular content from the tissue slice. Overall, all amino acid concentrations trended lower as an effect of time relative to tissue slicing. There were significant concentration decreases seen for histamine, lysine, and aspartate between time points 0-2 and 2-6 h (p < 0.05) relative to tissue slicing. Analysis of averaged sampling experiments does not appear to reveal significant probe-insertion-related amino acid changes. The work presented shows the applicability of an 80% reduction of probe tip size relative to previous designs for the collection of extracellular content from thin tissue slices.