Liquid Micro Research Articles

Utilizing Fisheye Cameras and Mass Spectrometry Imaging to Obtain Probing Coordinates for Histological Samples

Detecting chemical compositions in histological samples using mass spectrometry often requires time-consuming user interaction with a probe to ensure it is positioned as closely as possible to a sampling region. Fisheye cameras can obtain images of samples with a wide field-of-view; however, barrel distortion makes it difficult to analyze them as a flat plane. This research project aimed to develop an application that unwarps live images of histological samples captured with a fisheye camera and calculates the exact image-to-real-world probing coordinates with minor user interaction. Python’s PyQt5 and OpenCV libraries were utilized to create interactive software that removes fisheye distortion, finds image-to-real-world coordinates, and segments images. Connected hardware consisted of a Prusa 3D printer, liquid micro junction-surface sampling probe, fisheye camera, and LED light strips. The printer provided a bed for capturing sample images and control of the camera and probe within 1/100 of a millimetre. The software was outlined to process at least 2 photos of checkerboards for the fisheye undistortion, capture a photo of a sample to be unwarped, and require the user to map 4 points from the image to probe coordinates. Using this approach, real-world coordinates could be found for any image location. The application successfully unwarps live photos and converts image-to-real-world coordinates with sub-millimeter accuracy. Users can take new calibration photos, control lighting, save photos, and check undistortion entirely within the application to ensure all parameters are satisfactory. Coordinates of significant regions are displayed or may be manually selected, making it easier to sample specific areas. The success of unwarping relies on the camera’s focus and height, lighting, and object positioning. Future development plans to improve robustness and coordinate accuracy, and reduce the amount of calibration needed.

Dispersive Liquid–Liquid Micro Extraction: An Analytical Technique Undergoing Continuous Evolution and Development—A Review of the Last 5 Years

Over the years, monitoring the quality of the environment, food, and human health has emerged as a fundamental objective of scientific investigation. Various analytical techniques have been devised and continually refined to ensure a high standard of living. Among these methods, dispersive liquid–liquid microextraction (DLLME) stands out as a widely used approach to conduct analytical evaluations and pre-concentrations of chemical compounds. This review provides an account of the evolution of DLLME over the past five years (2018–2023). The Scopus search engine was used to search for scientific articles. The selection of relevant articles was carried out according to the criteria described below. Emphasis was placed on the evolution that DLLME has undergone over the years by integrating it with other pre-concentration methods in order to amplify the concentration factor and improve analytical precision. Factors such as solvent dispersion and extraction, dispersion formation, and the recovery of the solvent containing the extracted analytes were examined. Additionally, derivatization systems were evaluated to refine both qualitative and quantitative analysis. These efforts aim to introduce methods that are safe for operators, environmentally friendly, and economical. This review evaluates the advantages and disadvantages displayed by the evolution of this technique in the phases before, during, and after its application.

Microplastics and nanoplastics released from injection syringe, solid and liquid dimethylpolysiloxane (PDMS)

For a plastic syringe, a stopper at the end of plunger is usually made of polydimethylsiloxane (PDMS, and co-ingredients). To reduce friction and prevent leakage between the stopper and barrel, short chain polymer of liquid PDMS is also used as lubricant. Consequently, an injection process can release solid PDMS debris from the stopper and barrel, and liquid PDMS droplets from the lubricant, both of which are confirmed herein as solid and liquid micro(nano)plastics. From molecular spectrum perspective to directly visualise those micro(nano)plastics, Raman imaging was employed to analyse hundreds-to-thousands of spectra (hyper spectrum or hyperspectral matrix) and significantly enhance signal-to-noise ratio. From morphology perspective to provide high resolution of image, scanning electron microscopy (SEM) was engaged to cross-check with Raman images and increase assignment / quantification certainty. The weak Raman imaging signal of nanoplastics was extracted using image deconvolution algorithm to remove the background noise and average the signal variation. To increase the result’s representativeness and avoid quantification bias, multiple syringes were tested and multiple areas were randomly scanned toward statistical results. It was estimated that thousands of microplastics and millions of nanoplastics of solid/liquid PDMS might be injected when using a plastic syringe of 1 mL. Overall, Raman imaging (along with algorithm and SEM) can be helpful for further research on micro(nano)plastics, and it should be cautious to use plastic syringe due to the increasing concern on the emerging contamination of not only solid but also liquid micro(nano)plastics.

Patterned Liquid Micro Rails for the Transport of Micrometer Sized Chips

Patterned Liquid Micro Rails for the Transport of Micrometer Sized Chips

Antibacterial Activity of Terminalia mantaly Stem Ethanol Extract as Hand Sanitizer Gel

Background: Hand sanitizers generally contain alcohol. However, it can cause dry and irritated skin. Therefore, it is necessary to find antibacterial alternatives that are safe for the skin. One of the plants that has antibacterial activity is Terminalia mantaly (T. mantaly). This study aimed to investigate the antibacterial activity of ethanol extract and hand sanitizer gel of T. mantaly.Methods: The antibacterial activity test against gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and gram-negative bacteria (Escherichia coli and Shigella dysenteriae) was carried out using the liquid micro dilution method. The phytochemical tests were also performed. This study was conducted at the Chemistry Laboratory, Faculty of Sains and Informatics, Universitas Jenderal Achmad Yani in April-June 2022.Results: The ethanol extract of T. mantaly stem contained secondary metabolites of alkaloids, tannins, quinones, saponins, steroids, and flavonoids. The minimum inhibitory concentration (MIC) values of T. mantaly stem ethanol extract against Escherichia coli, Shigella dysenteriae, Staphylococcus aureus, Streptococcus pyogenes were 0.63%, 0.63%, 0.16%, and 0.16%, whereas the hand sanitizer gel gave MIC values of 0.63%; 0.31%; 0.16%; and 0.16% respectively. The minimum bactericidal concentration (MBC) values of T. mantaly stem ethanol extract and hand sanitizer gel had the same results, namely 2.50%, 0.16%, 1.25%, and 1.25%. The physical stability of the hand sanitizer gel from the ethanol extract of T. mantaly stem met the physical stability standards of the gel. Conclusions: The ethanol extract of the T. mantaly stems has stronger antibacterial activity against gram-positive bacteria than against gram- negative bacteria.

Utility perception of farmers towards PDKV Liquid Micro Grades

Utility perception of farmers towards PDKV Liquid Micro Grades

Application of liquid micro compound fertilizer to increase yield and agronomic feasibility of sweet corn

The objective of the research was to determine the appropriate dosage of liquid micro-compound fertilizer on crop yield and agronomic feasibility of sweet corn. This research was carried out in Mojokerto District on DS 2021, using of plot 4 m x 5 m with 10 treatments, using RBD, repeated 4 times. The treatment of liquid micro compound fertilizer (LMC), namely A. 0 kg.ha−1 Urea + 0 kg.ha−1 ZA + 0 kg.ha−1 NPK + 0 l.ha−1 LMC (control), B. 200 kg/ha Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 0 l.ha−1 LMC (standard), C. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 5 l.ha−1 LMC, D. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 10 l.ha−1 LMC, E. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK+15 l.ha−1 LMC, F. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 20 l.ha−1 LMC, G. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK+5 l.ha−1 LMC, H. 150 kg.ha−1 Urea+75 kg.ha−1 ZA+200 kg.ha−1 NPK+10 l.ha−1 LMC, I. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK + 15 l.ha−1 LMC, and J. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK + 20 l.ha−1 LMC. The results showed the application of 5 l.ha−1 LMC fertilizer combined with Urea 200 kg.ha−1 + ZA 100 kg.ha−1 + NPK 275 kg.ha−1 (treatment C) obtained the highest cob cornhusks weight of 13.66 t.ha−1 with RAE 120% and R/C ratio 3.13.

Spitting for Science: Non-Invasive Drug Monitoring Through a Modified Liquid Micro Junction-Surface Sampling Probe

The use of saliva as a convenient, non-invasive alternative for therapeutic drug monitoring has become increasingly favorable with the emergence of pharmacokinetic and bioequivalence research providing a link between blood plasma and saliva concentrations. Therapeutic drug monitoring is a practice through which specific drugs are monitored at given time intervals to maintain a constant concentration in the blood. It is only necessary for patients taking drugs with known pharmacokinetic variability, narrow therapeutic indices and potential adverse effects.
 Although the drug concentration in saliva is lower than in plasma, saliva has a complex matrix, consisting of salts, immunoglobins, proteins and more. The polar matrix in the saliva introduces potential interference with the sensitivity of the drug detection through salt suppression.
 In this project, 6 drugs used as anticonvulsants and antidepressants were analysed in artificial saliva using a modified version of the Liquid Micro Junction-Surface Sampling Probe (LMJ-SSP) to maximize the sensitivity of observed signals and minimize the detection limits.
 The main parameter which was targeted for optimizing the extraction and ionization of the drug in the saliva samples was the polarity of the carrier liquid, which continuously flows in the coaxial tube of the LMJ-SSP. Upon analyzing four different carrier liquids, the mixture containing methanol, water and chloroform was determined to provide the best sensitivity. Additionally, the enrichment factors of the peak areas using the chloroform mixture in the modified LMJ-SSP were enhanced by a factor ranging between 2.9 to 31.4, depending on the analyte.
 Overall, the data obtained from this project thus far displays that modifying the polarity by modifying the carrier liquid composition to balance the extraction and ionization during analysis using the modified LMJ-SSP optimizes the sensitivity of the detection.

Cultivation of white mustard under the conditions of the southern part of the Non-Chernozem zone of Russia

White mustard (Sinapis alba L.) is an environmentally friendly and eff ective resource of organic matter to increase the fertility of poor soils. Its seeds contain 30–40 % oil, 25–32 % protein, up to 1,0 % essential (mustard) oil, which is used in the pharmaceutical industry. It is widely used as a feed crop, on pasture and in the form of green top dressing before fl owering, it is well eaten by pigs and slightly worse by cattle. The period of good eating does not exceed 15–18 days. It is possible to improve its digestibility when sowing together with peas, vetch, and chin. White mustard mown at the beginning of fl owering improves the quality of milk and butter, which acquires a pleasant yellow color. A by-product of white mustard is the presscake obtained from its seeds after oil extraction. The presscake contains a lot of protein and fat. The purpose of the research was to improve the technological methods of white mustard production based on the use of various liquid complex fertilizers, sowing dates and herbicides that ensure high seed yield under the conditions of the southern part of the Non–Chernozem zone of Russia. It was found as a result of the research that the use of leaf processing in agrocenoses of white mustard with complex microbiological fertilizers had a stimulating eff ect on the growth and development of plants. The variety of Lucia was characterized by the maximum indicators of the crop structure in the variant with the combined use of Azotovite + Phosphatovite + Rauactive. In this variant, the maximum indicators of standing density were revealed 167,8 pcs/m2, which was higher than the control by 16,9 pcs/m2, plant height was 81,5 cm or higher than the control by 17,1 cm, the number of pods 56,5 pcs. per plant, which exceeded the control by 11,3 pcs. Non-root fertilizing with liquid micro fertilizers contributed to an increase in the indicators of the crop structure, in all studied variants. The maximum indicators for the variety of Lucia and the combined use of Mono-Boron + Mono-Zinc: the density of plants before harvesting was 146,6 pcs./m2, the height of plants was 67,8 cm, which was 9,8 cm higher than the control, the number of pods was 55,1 pcs. per plant, which exceeded the control by 1,1 pcs. The most favorable sowing period for formation of mustard plant is the second decade of May in the variant of a mixture of herbicides Galion + Miura.

Recent advances in ultra‐trace determination of uranium in natural water using total reflection X‐ray fluorescence (TXRF) spectrometry

AbstractThis review article describes some of the recent advances in ultra‐trace determination of uranium in various natural water bodies such as drinking water, underground water, seawater, etc. using total reflection x‐ray florescence (TXRF) spectrometry. Uranium is one of the most hazardous element having chemical as well as radio‐toxicity. However, due to its low concentration in water samples, direct determination is seldom possible in samples with high salt content. Various sample preconcentration and selective extraction techniques for uranium such as solvent extraction, dispersive liquid–liquid micro extraction, solid phase extraction, and membrane based preconcentration methods are summarized in this article. TXRF is a very versatile micro‐analytical technique with detection limits in picogram range and having multielemental analysis capability. TXRF determination of uranium using U Lα as the analytical line has many analytical challenges and difficulties, mainly due to the severe interference with Rb and Br, both are commonly available in natural water samples. This article highlights some of these challenges, along with the advantages and disadvantages of the different sample preparation techniques used so far for uranium determination in natural water samples by TXRF.

Dispersive Liquid - Liquid Micro extraction Technique Coupled with High Performance Liquid Chromatography Diode Array Detector for the Determination of Sulfonamides in Water Samples

A dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with diode array detection (DLLME-HPLC-DAD) has been developed for the determination of 15 sulfonamides in water samples. The effects of experimental parameters on the performance of the method such as the type and volume of extraction and disperser solvents, pH of the solution, effect of salt, and centrifugation time were evaluated, and optimum conditions were established. Under these optimum conditions, linearity was found in the range of 2 - 1 000 μg L-1 with regression coefficients better than 0.9990. The limit of detection (LOD) and limit of quantification (LOQ) values were in the range of 0.6 - 7.8 μg L-1 and 1.5 - 8.3 µg L-1, respectively. Intra-day and inter-day precision ranged from 1.5 - 9.7% and from 3.1 - 9.9%, respectively. The accuracy of the method were also evaluated in samples from three different sources of water (river water, groundwater, and tap water) were found to range from 70.5 to 103.9% with %RSD values ranging from 0.5 to 9.8%, with the exception of sulfaguanidine in river water and groundwater where the percentage recovery ranged from 54.3 - 84.9% at the two higher concentration levels (100 and 400 µg L-1).Furthermore, the effect of sample matrix on the extraction of target compounds was evaluated using the relative recovery (%RR) of the samples from three different water sources relative to the ultrahigh purity (UHP) water sample spiked with target analytes, and found in the range of 70.3 - 106.1%.The proposed method was successfully applied to wastewater treatment plant samples and Sulfisoxazole (SSO) was detected in the influent samples in the range of 14.8 - 17.8 µg L-1 with corresponding %RSD, (n = 5) value of 1.6% to 1.9%.The results indicated that the proposed method is effective for the extraction and determination of the sulfonamides in water samples.

Research on Theory and Simulation of Magnetic Liquid Micro Differential Pressure Sensor

With magnetic liquid micro differential pressure sensor as the research object, using the finite element analysis software COMSOL, magnetic liquid micro differential pressure sensor are analyzed and calculated by first hall element in the location of the magnetic field change curve, and then analyzed the magnetic liquid micro differential pressure sensor restoring force curve, analyzes the three different change trend of the spacing between the initial magnetic field force, And the change equation of magnetic force is fitted. Finally, the pressure resistance of the magnetic liquid micro-differential pressure sensor is calculated to ensure the integrity of the magnetic liquid sealing ring in the range of measurement, so that it has good sealing performance. The results show that when the distance between two cylindrical permanent magnets L=10mm, the magnetic flux density B at the central axis changes approximately linearly with the distance. The recovery force curve of permanent magnet has good linearity in the spacing range of 24mm ~ 40mm. The sensor has a four-stage magnetic liquid sealing ring, the overall pressure resistance value is four times the unilateral pressure resistance capacity, the theoretical pressure resistance value of magnetic liquid is 5000Pa.

HYPHa project: a low-cost alternative for integrated photonics

In this paper, a brief introduction to the Hybrid sensor platforms of integrated photonic systems based on ceramic and polymer materials (HYPHa) is presented. The project's goal is to establish a collaborative effort of institutes specialized in integrated optics. The newly formed group of professionals will be founded on research groups' experience, collaboration, and devotion. We intend to develop a method for combining competencies and a universal material platform for integrated photonics, based on newly validated hybrid materials as part of the project. Silica compounds with additions including TiO2, SnO2, used as structural matrices, polymer coatings with dopants (active or protective layers), organic dyes, and active two-dimensional materials such as transition metal dichalcogenides, graphene hybrids, and boron nitride will be the foundation for these materials. Full Text: PDF ReferencesK. Rola, A. Zajac, M. Czajkowski, A. Szpecht, M. Zdonczyk, M. Smiglak, J. Cybinska, K. Komorowska, "Ionic liquids for active photonics components fabrication", Opt. Mater. 89, 106-111 (2019). CrossRef D. Kowal, K. Rola, J. Cybinska, M. Skorenski, A. Zajac, A. Szpecht, M. Smiglak, S. Drobczynski, K. Ciesiolkiewicz, K. Komorowska, "Fluorescent ionic liquid micro reservoirs fabricated by dual-step E-beam patterning", Mater. Res. Bull. 142, 111434 (2021). CrossRef T. Martynkien, J. Olszewski, M. Szpulak, G. Golojuch, W. Urbanczyk, T. Nasilowski, F. Berghmans, and H. Thienpont, "Experimental investigations of bending loss oscillations in large mode area photonic crystal fibers", Opt. Express 15, 13547-13556 (2007). CrossRef E. Środa, J. Olszewski, and W. Urbańczyk, "Reducing bend-induced loss and crosstalk in a two-mode ridge waveguide by steplike thickness structuring", Appl. Opt. 61, 1164-1170 (2022). CrossRef P. Karasinski, C. Tyszkiewicz, A. Domanowska, A. Michalewicz, J. Mazur, "Low loss, long time stable sol–gel derived silica–titania waveguide films", Mater. Lett. 143, 5-7 (2015). CrossRef P. Karasinski, C. Tyszkiewicz, A. Maciaga, I.V. Kityk, E. Gondek, "Two-component waveguide SiO2:TiO2 films fabricated by sol–gel technology for optoelectronic applications", J. of Mater. Sci.: Mater. Electron. 26, 2733-2736 (2015). CrossRef M.A. Butt, A. Kazmierczak, C. Tyszkiewicz, P. Karasinski, R. Piramidowicz, "Mode Sensitivity Exploration of Silica–Titania Waveguide for Refractive Index Sensing Applications", Sensors 21, 7452 (2021). CrossRef A. Kazmierczak, M. Slowikowski, K. Pavlov, M. Filipiak, M. Vervaeke, C. Tyszkiewicz, H. Ottevaere, R. Piramidowicz, P. Karasinski, "Efficient, low-cost optical coupling mechanism for TiO2-SiO2 sol-gel derived slab waveguide surface grating coupler sensors", Opt. Appl. 50, 539 (2020). CrossRef M.A. Butt, S.N. Khonina, N.L. Kazanskiy, "A highly sensitive design of subwavelength grating double-slot waveguide microring resonator", Laser Phys. Lett. 17, 076201 (2020). CrossRef N.L. Kazanskiy, M.A. Butt, S.N. Khonina, "Silicon photonic devices realized on refractive index engineered subwavelength grating waveguides-A review", Opt. Laser Technol. 138, 106863 (2021). CrossRef M.A. Butt, S.N. Khonina, N.L. Kazanskiy, "Recent advances in photonic crystal optical devices: A review", Opt. Laser Technol. 142, 107265 (2021). CrossRef L. Xu, Y. Wang, E. El-Fiky, D. Mao, A. Kumar, Z. Xing, Md. G. Saber, M. Jacques, D.V. Plant, "Compact Broadband Polarization Beam Splitter Based on Multimode Interference Coupler With Internal Photonic Crystal for the SOI Platform", J. Light. Technol. 37, 1231 (2019). CrossRef R. Marchetti, C. Lacava, A. Khokhar, X. Chen, I. Cristiani, D.J. Richardson, G. T. Reed, P. Petropoulos, P. Minzioni, "High-efficiency grating-couplers: demonstration of a new design strategy", Sci. Rep. 7, 16670 (2017). CrossRef

Ultrasound-assisted deep eutectic solvent-based liquid–liquid microextraction for simultaneous determination of Ni (II) and Zn (II) in food samples

A new approach was developed for the simultaneous pre-concentration and determination of Ni (II) and Zn (II) in food samples. This method is based on ultrasound-assisted liquid–liquid micro extraction using hydrophobic deep eutectic solvent (DES) and 1,10-phenanthroline as chelating agent. The effect of several parameters, such as pH, selection and volume of DES, amount of chelating agent, time of sonication and centrifugation, was studied. Under optimized conditions, the developed procedure offered exceptional sensitivity and linearity. The limit of detection was approximately 0.029 µg/Kg and 1.5 µg/Kg for Ni (II) and Zn (II), respectively. The proposed method was applied for the pre-concentration and determination of Ni (II) and Zn (II) in hydrogenated edible oils, fishes, and milk samples. The results of this study were compared with reported methods in the literature revealing its advantages.

Depletable micro-layer for nucleate boiling simulations in micro-gravity conditions: A new approach

Nucleate boiling constitutes high heat flux with considerably low wall-superheat. During nucleate boiling, the evaporation of a thin liquid layer trapped between the vapor bubble and the wall is a significant contributor to the bubble growth rate and heat-flux. Direct simulation of the thin liquid layer is challenging because its thickness is only a few micrometers. In this paper we proposed a new approach to simulate the liquid micro layer. In this approach we do not directly model the thin liquid layer but instead we calculate its contribution to vapor bubble growth by estimating the micro layer thickness at each time step and then integrating the temperature gradient across the thin triangular region to calculate the heat flux and the generated vapor volume. In addition, our approach models the thin layer depletion with an added evaporation term in the equation. The added term is able to model the reduction in the thickness of the microlayer. Results for nucleate boiling simulations under microgravity conditions are reported using the proposed micro layer approach in comparison with experiments performed on the International Space Station using perfluoro-n-hexane as the test liquid. Results for bubble growth rate, bubble shape and heat-flux are in good agreement with experiments and are verified with two different time-instants in the bubble life cycle.

Influence of root feeding fertilizers on yield and quality of winter wheat grain in conditions of the central zone of Orenburg region

Agriculture continues to move forward confidently. Before our eyes, the agrarian industry is reviving, becoming stronger, taking a strong position at the forefront of the Russian economy. The most important achievement of 2017 was a record grain harvest of 130 million tons. This result was achieved not only by increasing the cultivated areas, which increased by 620 thousand hectares in 2017, but also thanks to the record yield, which amounted to 28 kg / ha, which is 80% higher than in 2000. The maximum harvest in the history of new and Soviet Russia, which will ensure our country a strong leadership in the world wheat market. Russian agriculture remains a driver of the country’s economic development. For the second year in a row, we get a record harvest of not only grain, but also sugar beets and sunflowers, the production of soybeans, rapeseed and greenhouse vegetables is growing. In the new season, grain exports will reach 45 million tons, including more than 35 million tons of wheat. Russia is expanding the geography of its presence, having mastered new directions for the supply of agricultural products. At the end of 10 months of 2017, grain exports increased by 22% compared to the same period in 2016 and amounted to 32 million tons. During the same time, the export of Russian wheat exceeded 24 million tons, which is 23% more than a year earlier. … In Russia, over 17 years, the volume of grain production increased 2 times, sugar beet and sunflower - 2-3 times, soybeans and rapeseed - 10, greenhouse vegetables - 1.8, poultry meat - 6, pork - 2. Fish - 2 times. Greenhouse vegetable growing and horticulture are developing intensively. Progress is being made in the development of animal husbandry and aquaculture. The dairy industry is undergoing a significant transformation, and production volumes on farms are growing. These are new growth points for the agro-industrial complex. Thanks to the achievements of domestic scientists, grain production of agricultural crops can be increased due to many factors. One of the factors is foliar dressing with liquid micro- and macro-fertilizers. Therefore, we studied various combinations of liquid micro-, macrofertilizers, as well as the bio-logical product Albit, in order to identify the best option and recommend it for produc-tion.

Simple and rapid analysis of Linagliptin in dried blood spot using an ionic liquid based vortex‐assisted dispersive liquid–liquid microextraction coupled with liquid chromatography–electrospray ionization–tandem mass spectrometry: Application to pharmacokinetic studies

AbstractA simple, rapid, and convenient ionic liquid based vortex‐assisted dispersive liquid–liquid micro extraction method for the determination of Linagliptin was developed. The main novelty of the present work deals with the analysis of Linagliptin in dried blood spot with significant advantages with regard to invasive sampling, volume of blood used (< 20 μL), storage and transport of biological materials and requirements for special biohazard arrangements. The extraction sample was assayed using liquid chromatography–tandem mass spectrometry using electropray ionization techniques. The effects of significant factors in extracting and disperser solvent, and salt contents were investigated. An efficient quantification method was developed for bioassay of Linagliptin using Sitagliptin as internal standard through Inertsil ODS‐3V (250 mm × 4.6 mm, 5 μm) column using 10 mM ammonium acetate buffer (pH adjusted to 4.6 with 0.1% Trifluoroacetic acid): Acetonitrile [10:90 (v/v)] as mobile phase. Tandem mass spectrometry detection was performed to monitor precursor → product ion transitions m/z 473.3 → 364.2 for Linagliptin, m/z 408.2 → 235.1 for internal standard. The assay was linear from 6 to 1500 ng/mL and the mean recoveries are more than 90%. The peak dried blood spot concentration (Cmax) after 1.5 h was determined to be 1391.2 ng/ml for Linagliptin.

Ionic liquid functionlized on multiwall carbon nanotubes for nickel and lead determination in human serum and urine samples by micro solid-phase extraction

In this study, a novel synthesis adsorbent, 1-(3-aminopropyl)-3-methylimidazolium hexafluorophosphate functionlized on multiwall carbon nanotubes ([Apmim][PF6]-MWCNTs, IL@MWCNTS) was used for nickel/lead (Ni/Pb) extraction and determination by dispersive ionic liquid micro solid-phase extraction (DIL-μ-SPE) coupled to electrothermal atomic absorption spectrometry (ET-AAS). After dilution of 20 mg of IL@MWCNTS in 200 μL of acetone, the mixture was injected to 10 mL of human serum/urine samples at pH of 8.0. After sonication for 5 min, the Ni(II) / Pb(II) were extracted by ionic liquid phase and then centrifuged for 2.5 min. The upper liquid phase set aside and Ni(II) / Pb(II) loaded in adsorbent were back-extracted by acidic solution at pH=2-3. Finally, the concentration of total nickel and lead was determined by ET-AAS. By optimizing, the limit of detection, linear range, and enrichment factor for nickel and lead were obtained (0.05 μg L−1; 0.1 μg L−1), (0.2-5.8 μg L−1; 0.4-30 μg L−1) and 24.7; 5.1, respectively (RSD less than 5%). Also, the capacity absorption of IL@MWCNTS for nickel and lead ions were achieved 149.3 mg g-1 and 162.5 mg g-1, respectively. The DIL-μ-SPE procedure was validated for nickel and lead extraction by spiking of real samples and ICP-MS analyzer.

Thiol modified bimodal mesoporous silica nanoparticles for removal and determination toxic vanadium from air and human biological samples in petrochemical workers

Investigation of exposure to toxic vanadium (V) in petrochemical workers is very important for human health, and it must be removed and determined in workplace air and human biological samples. In this research, the enriched adsorbent based on the thiol modified bimodal mesoporous silica nanoparticle (HS-UVM7) was used for the extraction vanadium in human blood by the dispersive sonication ionic liquid micro solid phase extraction (DS-IL-μ-SPE) at pH of 4.5. In addition, the vanadium (V) was removed from the industrial workplace air based on HS-UVM7 adsorbent by the liquid-solid phase-gas removal (LSP-GR). In the static and dynamic system, the vanadium (V) was removed from artificial air with HS-UVM7 and compared with the polyvinyl chloride membrane (PCM, sorbent in 7300 NIOSH). The LSP-GR procedure based on HS-UVM7 had more recovery and adsorption capacity as compared to PCM. The adsorption capacity of HS-UVM7 and UVM7 adsorbents were obtained 144.1 mg g−1 and 23.3 mg g−1, respectively. In addition, the main parameters effected on extraction vanadium in blood samples and removal from air were studied and optimized by ET-AAS. The LOD, RSD%, linear range (LR) and enrichment factor (EF) was achieved 0.03 μg L−1, 3.1, 0.1–4.5 μg L−1 and 48.7, respectively for extraction of vanadium in 10 mL of blood samples by the DS-IL-MSPE procedure. The validation of the methodology was confirmed by standard addition to gas phase and using certified reference materials (CRM, NIST) or ICP-MS in human blood samples.

Fluorescent ionic liquid micro reservoirs fabricated by dual-step E-beam patterning

In this work the fabrication of fluorescent microstructures through the e-beam induced solidification of two types of room temperature ionic liquids (RTILs) with fluorescent organic dyes is reported. It is shown that, by introducing dual-step e-beam patterning method with controlled accelerating voltage, solid micro-sized reservoirs are fabricated with liquid phase RTIL sealed inside. The presence of liquid inside the containers is confirmed by measuring their fluorescence spectra and comparison with results obtained for solid RTIL. The impact of the electron dose (ED) used in the exposure process on robustness and fluorescence characteristics of the fabricated structures is investigated. The temperature response of the micro reservoirs is also examined. The advantage of liquid – filled micro reservoirs is that they remain highly fluorescent, while solid RTIL structures exhibit significant fall in fluorescence ability associated with e-beam exposure damage.