Spray Mass Research Articles

Effects of Recess on the Self-Pulsation Characteristics of Liquid-Centered Swirl Coaxial Injectors

The self-pulsation characteristics of liquid-centered swirl coaxial injectors have been investigated using a Photron Fastcam SA-1.1 camera and a PULSE system (B&K Corp., 3650 type). The effects of both recess length and injection condition were analyzed and discussed. The flow pattern in the recess chamber of a liquid-centered swirl coaxial injector can be classified into three types, namely, outer, critical, and inner mixing flow. Once the critical flow approaches, self-pulsation is about to occur. When self-pulsation occurs, the spray oscillates with a Christmas tree shape. The Christmas-tree-like spray periodically produces droplet clusters, making horizontal spray width and mass flux oscillate periodically. Self-pulsation is the strongest when the flow is around the critical mixing flow. Both variations of recess length and injection condition can change the flow pattern in the recess chamber. When the flow pattern moves away from the critical mixing flow, self-pulsation is suppressed. All the frequency behaviors of self-pulsation indicate that self-pulsation is strongly related to Kelvin–Helmholtz instability. A possible mechanism of self-pulsation is also presented. This mechanism interprets the experiments of the present study and the results of literature well.

Ionization Suppression and Recovery in Direct Biofluid Analysis Using Paper Spray Mass Spectrometry.

Paper spray mass spectrometry is a method for the direct analysis of biofluid samples in which extraction of analytes from dried biofluid spots and electrospray ionization occur from the paper on which the dried sample is stored. We examined matrix effects in the analysis of small molecule drugs from urine, plasma, and whole blood. The general method was to spike stable isotope labeled analogs of each analyte into the spray solvent, while the analyte itself was in the dried biofluid. Intensity of the labeled analog is proportional to ionization efficiency, whereas the ratio of the analyte intensity to the labeled analog in the spray solvent is proportional to recovery. Ion suppression and recovery were found to be compound- and matrix-dependent. Highest levels of ion suppression were obtained for poor ionizers (e.g., analytes lacking basic aliphatic amine groups) in urine and approached -90%. Ion suppression was much lower or even absent for good ionizers (analytes with aliphatic amines) in dried blood spots. Recovery was generally highest in urine and lowest in blood. We also examined the effect of two experimental parameters on ion suppression and recovery: the spray solvent and the sample position (how far away from the paper tip the dried sample was spotted). Finally, the change in ion suppression and analyte elution as a function of time was examined by carrying out a paper spray analysis of dried plasma spots for 5 min by continually replenishing the spray solvent. Graphical Abstract ᅟ.

Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry.

Direct analysis and identification of long chain aliphatic primary diamine Duomeen O (n-oleyl-1,3-diaminopropane), corrosion inhibitor in raw water samples taken from a large medium pressure water tube boiler plant water samples at low LODs (<0.1 pg) has been demonstrated for the first time, without any sample preparation using paper spray mass spectrometry (PS-MS). The presence of Duomeen O in water samples was confirmed via tandem mass spectrometry using collision-induced dissociation and supported by exact mass measurement and reactive paper spray experiments using an LTQ Orbitrap Exactive instrument. Data shown herein indicate that paper spray ambient ionization can be readily used as a rapid and robust method for in situ direct analysis of polymanine corrosion inhibitors in an industrial water boiler plant and other related samples in the water treatment industry. This approach was applied for the analysis of three complex water samples including feedwater, condensate water, and boiler water, all collected from large medium pressure (MP) water tube boiler plants, known to be dosed with varying amounts of polyamine and amine corrosion inhibitor components. Polyamine chemistry is widely used for example in large high pressure (HP) boilers operating in municipal waste and recycling facilities to prevent corrosion of metals. The samples used in this study are from such a facility in Coventry waste treatment facility, U.K., which has 3 × 40 tonne/hour boilers operating at 17.5 bar.

Ambient Ionization Mass Spectrometry for Cancer Diagnosis and Surgical Margin Evaluation.

There is a clinical need for new technologies that would enable rapid disease diagnosis based on diagnostic molecular signatures. Ambient ionization mass spectrometry has revolutionized the means by which molecular information can be obtained from tissue samples in real time and with minimal sample pretreatment. New developments in ambient ionization techniques applied to clinical research suggest that ambient ionization mass spectrometry will soon become a routine medical tool for tissue diagnosis. This review summarizes the main developments in ambient ionization techniques applied to tissue analysis, with focus on desorption electrospray ionization mass spectrometry, probe electrospray ionization, touch spray, and rapid evaporative ionization mass spectrometry. We describe their applications to human cancer research and surgical margin evaluation, highlighting integrated approaches tested for ex vivo and in vivo human cancer tissue analysis. We also discuss the challenges for clinical implementation of these tools and offer perspectives on the future of the field. A variety of studies have showcased the value of ambient ionization mass spectrometry for rapid and accurate cancer diagnosis. Small molecules have been identified as potential diagnostic biomarkers, including metabolites, fatty acids, and glycerophospholipids. Statistical analysis allows tissue discrimination with high accuracy rates (>95%) being common. This young field has challenges to overcome before it is ready to be broadly accepted as a medical tool for cancer diagnosis. Growing research in new, integrated ambient ionization mass spectrometry technologies and the ongoing improvements in the existing tools make this field very promising for future translation into the clinic.

2D wax-printed paper substrates with extended solvent supply capabilities allow enhanced ion signal in paper spray ionization.

Paper-based microfluidic channels were created from solid wax printing, and the resultant 2D wax-printed paper substrates were used for paper spray (PS) mass spectrometry (MS) analysis of small organic compounds. Controlling fluid flow at the tip of the wax-printed paper triangles enabled the use of lower spray voltages (0.5-1 kV) and extended signal lifetime (10 minutes) in PS-MS. High sensitivity (sub ng mL(-1) levels) and quantitation precision (<10% RSD) have been achieved in the analysis of illicit drugs in 4 μL of raw urine (fresh and dry), as well as corrosion inhibitors and pesticides in water samples. The reported study encourages the future development of disposable 3D microfluidic paper-based analytical devices, which function with simple operation but capable of on-chip analyte detection by MS; such a device can replace the traditional complex laboratory procedures for MS analysis to enable on-site in situ sampling with portable mass spectrometers.

Coupling liquid-phase microextraction with paper spray for rapid analysis of malachite green, crystal violet and their metabolites in complex samples using mass spectrometry

Coupling liquid-phase microextraction (LPME) with paper spray mass spectrometry (PS-MS) to analyze malachite green, crystal violet and their metabolites.

Differentiation of Toxic and Non-Toxic Leaves of Jatropha curcas L. Genotypes by Leaf Spray Mass Spectrometry

Differentiation of Toxic and Non-Toxic Leaves of Jatropha curcas L. Genotypes by Leaf Spray Mass Spectrometry

Detection of signature forgery with erasable pens using paper spray mass spectrometry (PS-MS)

Paper spray mass spectrometry (PS-MS) is applied to a fast, sensible and reproducible detection of forgery in signatures made with erasable pens.

Improving the analytical performance and versatility of paper spray mass spectrometry via paper microfluidics

Two paper-based microfluidic techniques, photolithography and wax patterning, were investigated for their potential to improve upon the sensitivity, reproducibility, and versatility of paper spray mass spectrometry. The main limitation of photolithography was the significant signal (approximately three orders of magnitude) above background which was attributed to the chemicals used in the photoresist process. Hydrophobic barriers created via wax patterning were discovered to have approximately 2 orders of magnitude less background signal compared to analogous barriers created using photolithography. A minimum printed wax barrier thickness of approximately 0.3 mm was necessary to consistently retain commonly used paper spray solvents (1 : 1 water : acetonitrile/methanol) and avoid leakage. Constricting capillary flow via wax-printed channels yielded both a significant increase in signal and detection time for detection of model analytes. This signal increase, which was attributed to restricting the radial flow of analyte/solvent on paper (i.e., a concentrating effect), afforded a significant increase in sensitivity (p ≪ 0.05) for the detection of pesticides spiked into residential tap water using a five-point calibration curve. Finally, unique mixing designs using wax patterning can be envisioned to perform on-paper analyte derivatization.

Metal–organic framework coated paper substrates for paper spray mass spectrometry

Metal–organic frameworks (MOFs) have emerged as novel materials owing to their inherent structural characteristics, i.e., a large surface area and a well-ordered porous structure, but there are no reports on their application to paper spray mass spectrometry. Herein we explore the capability of paper substrates coated with three types of MOFs [e.g., MIL-53(Al), ZIF-8 and UiO-66(Zr)] for paper spray, in which the as-prepared UiO-66(Zr) coated paper demonstrated the highest sensitivity in the analysis of therapeutic drugs in dried blood spots relative to MIL-53(Al) and ZIF-8 coated paper substrates. To get a better understanding on the interactions between drugs and MOF coated papers, much effort has been focused on the elution behaviors of target drug verapamil from the MOF coated papers and the adsorption ability of the studied analyte to MOF particles in solution systems. Due to the more favorable elution behaviors and weaker adsorption ability of the tested drugs at the surface of UiO-66(Zr) coated paper relative to the other two papers, the estimated lower limit of quantitation (LLOQ) values of the examined drugs with UiO-66(Zr) coated paper have improvements of 8.5–46.6-fold relative to those from uncoated filter paper, and the values were in the range of 0.04–0.65 ng mL−1. Based on the high sensitivity of UiO-66(Zr) coated paper in drug quantitative analysis, the developed paper has also been successfully applied for the analysis of five anti-psychotic drugs (e.g., clozapine, amisulpride, quetiapine, risperidone and aripiprazole) in 40 human blood samples.

Rapid screening of agrochemicals by paper spray ionization and leaf spray mass spectrometry: which technique is more appropriate?

Paper Spray Ionization and Leaf Spray were compared by detection and quantification of agrochemicals.

A new insert sample approach to paper spray mass spectrometry: a paper substrate with paraffin barriers.

The analytical performance for paper spray (PS) using a new insert sample approach based on paper with paraffin barriers (PS-PB) is presented. The paraffin barrier is made using a simple, fast and cheap method based on the stamping of paraffin onto a paper surface. Typical operation conditions of paper spray such as the solvent volume applied on the paper surface, and the paper substrate type are evaluated. A paper substrate with paraffin barriers shows better performance on analysis of a range of typical analytes when compared to the conventional PS-MS using normal paper (PS-NP) and PS-MS using paper with two rounded corners (PS-RC). PS-PB was applied to detect sugars and their inhibitors in sugarcane bagasse liquors from a second generation ethanol process. Moreover, the PS-PB proved to be excellent, showing results for the quantification of glucose in hydrolysis liquors with excellent linearity (R(2) = 0.99), limits of detection (2.77 mmol L(-1)) and quantification (9.27 mmol L(-1)). The results are better than for PS-NP and PS-RC. The PS-PB was also excellent in performance when compared with the HPLC-UV method for glucose quantification on hydrolysis of liquor samples.

Macroscopic spray characteristics of wide distillation fuel (WDF)

In this study, the performance of piezoelectric and solenoid injectors were compared. With a piezoelectric injector, the spray characteristics of kerosene and G50 (gasoline/diesel blend fuel), which are kinds of WDF, were investigated and compared to diesel. The characteristics such as spray penetration, spray velocity, spray angle and air entrainment were used to understand the spray behaviour of the test fuels. The results indicate that the piezoelectric injector shows significant improvement over the conventional solenoid injector in injection response and needle opening speed, which enables precise and rapid control of injection. The trade-off effects of charge density and injection pressure on spray penetration and spray velocity are quite clear, while spray angle is almost insensitive to injection pressure. Kerosene and G50 give smaller but similar spray penetration and velocity compared to diesel. The spray angle of kerosene and G50 are larger compared to diesel. The spray volume and mass of entrained air for kerosene and G50 are higher compared to diesel, which indicates kerosene and G50 can form better fuel–air mixing, which is very important for the performance of engine when fuelled by WDF.

Nanofluids spray heat transfer enhancement

Spray cooling experiments were carried out to study the effect of seven (7) different types of nanofluids on heat transfer enhancement. Three different concentrations of 0.04%, 0.07%, and 0.1% by volume of Ag, Al, Al2O3, Fe3O4, SiO2, TiO2 and multi-walled carbon nanotubes (MWCNTs) dispersed with deionized (DI) water were tested, and transient as well as steady spray boiling experiments were conducted over a copper flat plate heater 4cm2 in size with a 1cm thickness. The spray was issued by a 270μm full-cone nozzle with a spray height of 30mm and a spray mass flux of 1.5×10−3kg/cm2s. Both a transient cooling curve and steady boiling curve were obtained. The results revealed that the average heat transfer coefficient (HTC), as well as the associated critical heat flux (CHF), are significantly enhanced, and the enhancement ratio can be up to 1.7 (HTC) and 1.84 (CHF), respectively, corresponding to the DI water as the nanofluids’ volume fraction increased from 0.04% to 0.1%.

Engineering cell-compatible paper chips for cell culturing, drug screening, and mass spectrometric sensing.

Paper-supported cell culture is an unprecedented development for advanced bioassays. This study reports a strategy for in vitro engineering of cell-compatible paper chips that allow for adherent cell culture, quantitative assessment of drug efficiency, and label-free sensing of intracellular molecules via paper spray mass spectrometry. The polycarbonate paper is employed as an excellent alternative bioscaffold for cell distribution, adhesion, and growth, as well as allowing for fluorescence imaging without light scattering. The cell-cultured paper chips are thus amenable to fabricate 3D tissue construction and cocultures by flexible deformation, stacks and assembly by layers of cells. As a result, the successful development of cell-compatible paper chips subsequently offers a uniquely flexible approach for in situ sensing of live cell components by paper spray mass spectrometry, allowing profiling the cellular lipids and quantitative measurement of drug metabolism with minimum sample pretreatment. Consequently, the developed paper chips for adherent cell culture are inexpensive for one-time use, compatible with high throughputs, and amenable to label-free and rapid analysis.

Cell-patterned glass spray for direct drug assay using mass spectrometry

In this work, the establishment of a glass spray mass spectrometry (GS-MS) platform for direct cell-based drug assay was described. Cell co-culture, drug-induced cell apoptosis, proliferation analysis and intracellular drug absorption measurement were performed simultaneously on this specifically designed platform. Two groups of co-cultured cells (NIH-3T3/HepG2 and HepG2/MCF-7) were cultivated and they showed high viability within 3 days. The biocompatibility of the platform facilitated the subsequent bioassays, in which, cyclophosphamide (CPA) and genistein were used as the model drugs. The distinctions of cell apoptosis and proliferation between the mono-cultured and co-cultured cells were clearly observed and well explained by in situ GS-MS measurements. A satisfactory linearity of the calibration curve between the relative MS intensity and CPA concentrations was obtained using stable isotope labeling method (y = 0.16545 + 0.0985x, R2 = 0.9937). The variations in the quantity of absorbed drug were detected and the results were consistent with the concentration-dependence of cell apoptosis. All the results demonstrated that direct cell-based drug assay could be performed on the stable isotope labeling assisted GS-MS platform in a facile and quantitative manner.

Catalytic Vicinal Diacylation of Epoxidized Triglycerides in Canola Oil

AbstractThe epoxy ring opening and vicinal diacylation of fatty acids in vegetable oils was found to be promising reaction to synthesize stable biolubricants and bioplasticizers. The current research investigation is emphasized on the synthesis of a value added product vicinally diacylated canola oil by sulfated‐ZrO2. The two‐step research approach employed includes: (i) epoxidation, and (ii) epoxy ring opening and vicinal diacylation of epoxidized triglycerides in the canola oil. Sulfated‐ZrO2 was prepared and characterized to measure the physico‐chemical properties required for the effective catalysis. The Taguchi (L16 orthogonal array) statistical design method was employed to optimize the process conditions for the maximum formation of diacylated canola oil. Sulfated‐ZrO2 demonstrated promising activity for the epoxy ring opening and vicinal diacylation of canola oil, and 99 % conversion was achieved at the optimum process conditions of temperature 130 °C, epoxy to acetic anhydride molar ratio (1:1.25), 16 wt% of catalyst loading and reaction time of 1 h which were inferred from the Taguchi analyses. The products were characterized and confirmed with FT‐IR, 1H NMR and sodium spray mass spectroscopy. Spectroscopic analysis also confirmed the absence of intermediate products. The statistical analyses was undertaken to determine the order, rank and interactions among the process variables. The reaction followed Langmuir–Hinshelwood–Hougen–Watson type mechanism and the kinetic data was fitted in overall second order equation. Calculated apparent activation energy was 23.1 kcal/mol.

A model for a non-uniform spray evaporator taking into account the effect of non-isothermal polydisperse droplets

A mathematical model of the water spray heat and mass transfer equipment with co-current flow of air and water droplets has been developed to investigate the effect of polydispersity of droplet size and the effect of spatial non-uniformity of the spray on evaporation performance. Our simulation results revealed that the simplifying assumption of constant droplet temperature led to significant errors when the droplet size distribution was strongly polydisperse. Numerous simulations showed that the average droplet diameter, droplet size distribution and the radial distribution of water spray significantly affected the changes in properties of air and water droplets. For polydisperse droplets with non-uniform spray, the case of a narrower droplet size distribution (σ=0.2) showed a faster decrease in the averaged diameter and temperature of the droplets, which were associated with a faster temperature decrease and humidity increase of the contacting air, than the case of broader droplet size distribution (σ=0.4) with the same volume-averaged diameter.

Experimental and Simulation Study on the Performance of Counter Flow Closed Cooling Tower Systems

Cooling towers are required in building HVAC systems that use water as the cooling condenser fluid. Cooling towers used in this study are of the forced draft, counter flow, indirect/closed evaporative type. This study sought to demonstrate the performance characteristics of a closed system cooling tower by its effectiveness value, Number of Transfer Units (NTU), cooling capacity, and overall heat transfer and mass coefficient of the cooling tower. Experiments were performed on a heat exchanger coil intercrossed with ⅜ inch diameter intersections on parallel lines. Results of the experiment were then compared with the heat and mass transfer correlations taken from previous studies, and also combined with Computational Fluid Dynamics (CFD) simulations to examine the physical processes that occur in the cooling towers. All the experimental results, theoretical calculations and CFD simulations used variations of warm water mass, cold air, and water spray to present a clear description of the performance characteristics of a closed system cooling tower. The results of this study have shown that an increase in the amount of water spray mass flow causes an increase in the effectiveness value, heat transfer and overall mass transfer, as well as the cooling capacity of the cooling tower. The waste heat typically utilizes up to 80% of latent evaporation heat, and 20% of sensible air heat; however, waste heat in the closed system cooling tower utilizes 100% of latent evaporation heat. The mass transfer coefficient rate tends to be stable for a small mass of water spray.

Offshore drilling rig ice accretion modeling including a surficial brine film

This article presents an extension of the two-dimensional icing model ICEMOD2. In contrast to this model the new model (called ICEMOD2.1) considers the inertia terms in the momentum equation. The derivation of the model is presented and the model is applied to two typical structures of an offshore drilling rig which may be exposed to spray icing: a corner column and a truss. A mean impact-generated spray mass flux formula (called the “normal” value) based on droplet kinematics and spray measurements on the Norwegian semi-submersible rig “Treasure Scout” has been implemented in the model. The model results showed satisfactory agreement with some actual icing registration data from the drilling rigs “SEDCO 708” and “SEDCO 709”. Additionally sensitivity tests are presented for a selected section of a rig column of diameter 5.0m varying air temperatures, wind speeds and spray frequencies as expected ice accretion increases with decreasing air temperature. With the chosen formula for the spray mass flux and wind speed (17–25ms−1) ice accretion also increases with increasing wind speed. The available field results of Treasure Scout enable us only to construct a time-average spray mass flux formula independent of spray frequency. The single spray mass flux is then in the model a derived quantity obtained by dividing the time-average value by the product of spray frequency and spray duration. Based on these presumptions the sensitivity tests show that spray frequency variations have only a minor effect upon accreted ice load when normal spray mass flux is assumed (corresponding here to 5–10gm−2s−1). If however the spray mass flux is put 25 times as large as the normal value a substantial increase in model ice load with increasing spray frequency is obtained. Probably this is due to a large increase in brine film thickness (a factor of about 10). A possible theoretical explanation is given in the text. Finally the significance of brine film motion in icing modeling has been discussed. It turns out that for cylinder icing ICEMOD2.1 and ICEMOD2 give the same ice load and thickness distribution. The only noticeable difference in the two model results is the brine film horizontal velocity, but only for an increased spray mass flux (of order 102‐103gm−2s−1). For normal spray mass flux a simplified time-dependent model version with brine film velocity put equal to zero (Model01) gives similar ice accretion results as ICEMOD2.1. Even a stationary version of the latter model (Model02) gives adequate results for normal spray conditions. For the increased spray mass flux some brine may however be pushed over to the lee side by wind stress, especially if the cylinder is slim such as a truss, and only the complete versions of ICEMOD2.1 or ICEMOD2 can handle this situation. Model01 will still give correct ice thickness results on the major part of the upwind side of the cylinder while Model02 only will give some icing close to the cylinder shoulders (which means that this model cannot approximate periodic icing in this case).