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Syringe Pump (syringe + pump)

Distribution by Scientific Domains

Life Sciences	50%
Chemistry	30%

Selected Abstracts

Direct automatic determination of free and total anesthetic drugs in human plasma by use of a dual (microdialysis,microextraction by packed sorbent) sample treatment coupled at-line to NACE,MS

ELECTROPHORESIS, Issue 10 2009
Gabriel Morales-Cid
Abstract This paper reports for the first time the use of microextraction by packed sorbent in combination with CE. The combined system was used to determine anesthetic drugs in human plasma. A microdialysis fiber was coupled on-line to the microextraction unit in order to distinguish between free and total concentrations of drugs. The system was automated by connecting the microextraction unit to a syringe pump and interfacing it to a computer. The ensuing method allows the determination of 10,,g/L concentrations of free drugs and 1,,g/L concentrations of total drugs from only 200,,L of sample with an RSD of less than 9%. [source]

A multilayer poly(dimethylsiloxane) electrospray ionization emitter for sample injection and online mass spectrometric detection

ELECTROPHORESIS, Issue 24 2005
Jamie M. Iannacone
Abstract An ESI emitter made of poly(dimethylsiloxane) interfaces on-chip sample preparation with MS detection. The unique multilayer design allows both the analyte and the spray solutions to reside on the device simultaneously in discrete microfluidic environments that are spatially separated by a polycarbonate track-etched, nanocapillary array membrane (NCAM). In direct spray mode, voltage is applied to the microchannel containing a spray solution delivered via a syringe pump. For injection, the spray potential is lowered and a voltage is applied that forward biases the membrane and permits the analyte to enter the spray channel. Once the injection is complete, the bias potential is switched off, and the spray voltage is increased to generate the ESI of the injected analyte plug. Consecutive injections of a 10,,M bovine insulin solution are reproducible and produce sample plugs with limited band broadening and high quality mass spectra. Peptide signals are observed following transport through the NCAM, even when the peptide is dissolved in solutions containing up to 20% seawater. The multilayer emitter shows great potential for performing multidimensional chemical manipulations on-chip, followed by direct ESI with negligible dead volume for online MS analysis. [source]

Chemiluminescence determination of chlorpheniramine using tris(1,10-phenanthroline),ruthenium(II) peroxydisulphate system and sequential injection analysis

LUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 1 2009
Fakhr Eldin O. Suliman
Abstract A sequential injection (SI) method was developed for the determination of chlorpheniramine (CPA), based on the reaction of this drug with tris(1,10-phenanthroline),ruthenium(II) [Ru(phen)32+] and peroxydisulphate (S2O82,) in the presence of light. The instrumental set-up utilized a syringe pump and a multiposition valve to aspirate the reagents [Ru(phen)32+ and S2O82,] and a peristaltic pump to propel the sample. The experimental conditions affecting the chemiluminescence reaction were systematically optimized, using the univariate approach. Under the optimum conditions linear calibration curves of 0.1,10 µg/ml were obtained. The detection limit was 0.04 µg/ml and the relative standard deviation (RSD) was always < 5%. The procedure was applied to the analysis of CPA in pharmaceutical products and was found to be free from interferences from concomitants usually present in these preparations. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Analysis of estrogenic contaminants in river water using liquid chromatography coupled to ion trap based mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 14 2002
Tom Benijts
A precise and reliable method, using liquid chromatography combined with ion trap based mass spectrometry, for the determination of three endogenous estrogens, namely, estrone, estradiol, and estriol, and two synthetic estrogens, ethinyl estradiol and diethylstilbestrol, in environmental water samples was developed. Optimization of the parameter settings of the ion source and mass analyzer as well as evaluation of solvent composition were carried out by continuous introduction of standards through a syringe pump. In negative ion mode the electrospray ionization source gave acceptable results. The optimum solvent used consisted of water/acetonitrile, with no volatile bases or buffers added. A simple, off-line, manual solid-phase extraction method was developed for sample preparation of environmental water samples. Recoveries were over 86% for all compounds. The method was validated and found to be linear, selective, and robust. For analysis of a 50-mL sample, the limit of detection (LOD) ranged from 3.2 to 10.6,ng/L for all compounds, and the limit of quantitation (LOQ) from 10.6 to 35.0,ng/L. Within-day (n,=,5) and total (n,=,5) reproducibility were investigated at three different concentration levels and ranged from 6.2 to 9.5% and 9.4 to 12.1%, respectively. Finally, the method was applied to real-world samples. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Regional hydrodynamic gene delivery to the rat liver with physiological volumes of DNA solution

THE JOURNAL OF GENE MEDICINE, Issue 6 2004
Xiaohong Zhang
Abstract Background The major barrier to the clinical application of hydrodynamic gene delivery to the liver is the large volume of fluid required using standard protocols. Regional hydrodynamic gene delivery via branches of the portal vein has not previously been reported, and we have evaluated this approach in a rat model. Methods The pGL3 plasmid with the luciferase reporter gene was used at 50 µg/ml in isotonic solutions, and was administered with a syringe pump for precise control of the hydrodynamic conditions evaluated. Gene expression was individually measured in six anatomically distinct liver lobes. The effect of systemic chloroquine to promote endocytic escape and a (Lys)16 -containing peptide to condense the DNA into ,100-nm nanoparticles was also evaluated. Results Hydrodynamic conditions for excellent gene delivery were obtained by using 3-ml volumes (,12 ml/kg) of isotonic DNA solution delivered at 24 ml/min to the right lateral lobe (,20% of the liver mass). Under these conditions, >95% of gene delivery usually occurred in the targeted right lateral lobe. Outflow obstruction was essential for gene delivery, both at optimal and at very low levels of hydrodynamic gene delivery. The use of systemic chloroquine to promote endocytic escape did not augment hydrodynamic gene delivery, while condensation of DNA in non-ionic isotonic solutions (5% dextrose) to nanoparticles of ,100 nm completely abolished gene delivery. Conclusions Regional hydrodynamic gene delivery via a branch of the portal vein offers a physiological model of liver gene therapy, for experimental and clinical application. Copyright © 2004 John Wiley & Sons, Ltd. [source]

The effects of syringe plunger design on drug delivery during vertical displacement of syringe pumps

ANAESTHESIA, Issue 11 2000
M. Weiss
Fluid delivery from four types of commercially available 50-ml syringes was measured using an electronic balance at an infusion rate of 1 ml.h,1. Retrograde aspiration volume and zero-drug delivery time were recorded after lowering the syringe pump by 50 cm. Syringe compliance was calculated from the volume of bolus released after occlusion at 100 mmHg. Zero-drug delivery times differed significantly between syringes, ranging from [mean (SD)] 3.26 (0.40) min to 6.38 (0.56) min (F = 55.5, d.f. = 3/20, p < 0.0001). Syringe compliance correlated well with aspiration volume (Pearson r2 = 0.92, p < 0.001) and zero-drug delivery time (r2 = 0.90, p < 0.001). Syringe design affected the internal syringe compliance. All syringes were associated with potentially relevant zero-drug delivery times after moderate vertical displacement. To minimise this risk, vertical displacement of syringe pumps delivering highly vasoactive drugs should be avoided. [source]

Microchannels Constructed on Rough Hydrophobic Surfaces

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 8 2008
M. Watanabe
Abstract A microchannel was constructed between two glass slides, taking advantage of their surface properties. The channel geometry was defined by a line that was previously printed on the slide surface using a highly water-soluble liquid [2-(2-ethoxyethoxy)ethanol] as the ink. Water, which acted as the working fluid flowed along this line. Although the channel did not have any sidewalls, the water was fixed along the printed line due to the large contact-angle hysteresis of the slide surface whose properties were rough and hydrophobic. Such roughness was more advantageous over smoothness due to the large contact-angle hysteresis of water and the good wettability of the ink. Using a syringe pump, the water was able to continuously flow through a 1,mm wide and 0.13,mm deep channel without flooding. [source]

An accessible micro-capillary electrophoresis device using surface-tension-driven flow

ELECTROPHORESIS, Issue 9 2009
Swomitra K. Mohanty
Abstract We present a rapidly fabricated micro-capillary electrophoresis chip that utilizes surface-tension-driven flow for sample injection and extraction of DNA. Surface-tension-driven flow (i.e. passive pumping) [G. M. Walker et al., Lab. Chip. 2002, 2, 131,134] injects a fixed volume of sample that can be predicted mathematically. Passive pumping eliminates the need for tubing, valves, syringe pumps, and other equipment typically needed for interfacing with microelectrophoresis chips. This method requires a standard micropipette to load samples before separation, and remove the resulting bands after analysis. The device was made using liquid phase photopolymerization to rapidly fabricate the chip without the need of special equipment typically associated with the construction of microelectrophoresis chips (e.g. cleanroom) [A. K. Agarwal et al., J. Micromech. Microeng. 2006, 16, 332,340; S. K. Mohanty et al., Electrophoresis 2006, 27, 3772,3778]. Batch fabrication time for the device presented here was 1.5,h including channel coating time to suppress electroosmotic flow. Devices were constructed out of poly-isobornyl acrylate and glass. A standard microscope with a UV source was used for sample detection. Separations were demonstrated using Promega BenchTop 100,bp ladder in hydroxyl ethyl cellulose (HEC) and oligonucleotides of 91 and 118,bp were used to characterize sample injection and extraction of DNA bands. The end result was an inexpensive micro-capillary electrophoresis device that uses tools (e.g. micropipette, electrophoretic power supplies, and microscopes) already present in most labs for sample manipulation and detection, making it more accessible for potential end users. [source]

Application of a microfluidic device for counting of bacteria

LETTERS IN APPLIED MICROBIOLOGY, Issue 3 2006
K.-I. Inatomi
Abstract Aims:, To develop a miniaturized analytical system for counting of bacteria. Methods and Results:,Escherichia coli cells were used throughout the experiments. The system consists of a microfluidic chamber, a fluorescence microscope with a charge-coupled device (CCD) camera and syringe pumps. The chamber was made of a silicone rubber (30 × 30 mm and 4 mm high). The E. coli cells were flowed from a micro-nozzle fabricated in the chamber and detected with the CCD camera. The individual cells were indicated as signal peaks on a computer. The cell counts showed a good correlation compared with that of a conventional plate counting method, and results of the simultaneous detection of live and dead cells were also presented. Conclusions, Significance and Impact of the Study:, The system having a small disposable nozzle has the advantages for low cost and safe medical or environmental analysis, when compared with a conventional flow cytometer. This is the first step of the development of a one-chip microbe analyzer. [source]