Simple Extraction Technique Research Articles

Quantitation of cocaine and cocaethylene in small volumes of rat whole blood using gas chromatography-mass spectrometry

A simple solid phase extraction (SPE) technique combined with gas chromatography-mass spectrometry (GC/MS) operated in selected ion monitoring (SIM) mode is described for quantitation of cocaine and cocaethylene in small samples (250 μl) of rat whole blood. Use of ( N-[ 2H 3C])-cocaine and (N- [ 2H 3C])-cocaethylene internal standards resulted in high sensitivity and selectivity for this analytical method. Analysis was performed using a Hewlett-Packard 5890 GC equipped with a 7673A Automatic Liquid Sampler linked to a Hewlett-Packard 5972 Mass Selective Detector. Separation of analytes was accomplished on a cross-linked methyl silicone gum capillary column (Ultra 1: 12m × 0.2mm (i.d.) × 0.33 μm). Linearity was established over a wide range of concentrations (5.0–2000.0 ng ml −1) with good precision. Limits of detection (LOD) were 1.0 and 2.0 ng ml −1 for cocaine and cocaethylene, respectively. This analytical method was designed for use in pharmacokinetic experiments studying the formation of cocaethylene following ethanol pretreatment in rats administered cocaine.

Spatio-temporal video segmentation using a joint similarity measure

This paper presents a new morphological spatio-temporal segmentation algorithm. The algorithm incorporates luminance and motion information simultaneously and uses morphological tools such as morphological filters and watershed algorithm. The procedure toward complete segmentation consists of three steps: joint marker extraction, boundary decision, and motion-based region fusion. First, the joint marker extraction identifies the presence of homogeneous regions in both motion and luminance, where a simple joint marker extraction technique is proposed. Second, the spatio-temporal boundaries are decided by the watershed algorithm. For this purpose, a new joint similarity measure is proposed. Finally, an elimination of redundant regions is done using motion-based region fusion. By incorporating spatial and temporal information simultaneously, we can obtain visually meaningful segmentation results. Simulation results demonstrates the efficiency of the proposed method.

A novel procedure for the extraction of protein deposits from soft hydrophilic contact lenses for analysis

PURPOSE. A quick, simple, and efficient extraction technique was developed for the removal of protein from soft hydrophilic contact lenses. METHODS. An extraction solvent consisting of a 50:50 mix of 0.2% trifluoroacetic acid and acetonitrile was used to remove protein from in vitro laboratory-deposited and human-worn contact lenses. The protein removed was analyzed using HPLC, bicinchoninic acid (BCA) analysis, and SDS-PAGE gel electreophoresis. RESULTS. Extraction efficiency for lysozyme from laboratory-deposited Group IV lenses was determined to be ~100%. Group IV human-worn contact lenses were extracted and analyzed for lysozyme by HPLC and total protein by bicinchoninic acid (BCA) analysis. Groups I, II, III, and IV contact lenses deposited with an artificial tear protein solution and human-worn lenses were extracted and analyzed by SDS-PAGE gel electreophoresis and micro-BCA. CONCLUSIONS. The ACN/TFA procedure offers a simple, quick, and efficient extraction technique for removal of protein from contact lenses for subsequent analysis.

A simple method for on-chip, sub-femto Farad interconnect capacitance measurement

In this letter, a sensitive and simple technique for parasitic interconnect capacitance measurement and extraction is presented. This on-chip technique is based upon an efficient test structure design that utilizes only two transistors in addition to the unknown interconnect capacitance to be characterized. No reference capacitor is needed. The measurement itself is also simple; only a dc current meter is required. Furthermore, the extraction methodology employs a self-checking algorithm to verify that the extracted capacitance value is consistent and accurate. The technique is demonstrated by extracting the capacitance of a single crossover between a Metal 1 line and a Metal 2 of 0.44 fF. The resolution limit is dominated by the matching of the minimum sized transistors used for the test structure. We estimate this resolution limit to be about 0.03 fF.

Simple solvent extraction technique for elimination of matrix interferences in the determination of methylmercury in environmental and biological samples by ethylation-gas chromatography-cold vapor atomic fluorescence spectrometry

A solvent extraction technique involving no critical clean-up steps was developed for the determination of methylmercury (MeHg) in environmental and biological samples by aqueous phase ethylation, room temperature precollection, gas chromatographic separation and cold vapor atomic fluorescence spectrometric detection. Samples were first digested with KOH-methanol. then acidified prior to extraction with methylene chloride. MeHg was back-extracted from the solvent phase into water prior to aqueous phase ethylation. Recoveries close to 100% were obtained with RSDs less than 5% for all samples analyzed, making direct standardization possible. The detection limits were about 0.08 ng g −1 when analyzing 0.1 g of dry sea plant homogenate and 0.02 ng g when analyzing 0.5 g of wet sediment samples. Various certified reference materials and intercomparison samples, including sediments, sea plants and tissues, were analyzed, and the results were in good agreement with the certified values. The technique was applied to the determination of MeHg in both sea plants from the Atlantic and the red blood protein of dolphins from the Mediteranean Sea. in sediments from the Mediterranean Sea and Minnesota rivers and in soils from different origins. Concentrations of MeHg in dolphin red blood protein samples were as high as 300 ng g −1.

Establishment of a reliable extraction method of estrone sulfate from bovine plasma for detection of the peripheral level during the regular estrous cycle by radioimmunoassay

A simple extraction and assay technique of estrone sulfate in bovine blood was developed with the object of detecting the peripheral level of estrone sulfate in a normal estrous cycle or in early pregnancy. Estrone sulfate in bovine plasma was extracted with a small reversed phase cartridge. The steroid conjugate retained in the cartridge was eluted with 40% (v/v) methanol. Estrone sulfate was separately recovered from other steroids by the stepwise increase in methanol concentration in the elution solvent. The recoveries of estrone sulfate eluted with 40% methanol were more than 90%, irrespective of the applied plasma volume. The concentration measured by radioimmunoassay with the eluent of 40% methanol was consistent for plasma extraction volumes of 0.5–2.0 ml. The change of estrone sulfate in bovine peripheral plasma during the regular estrous cycle was determined with a small reversed phase cartridge for extraction and 40% methanol for elution. The change in estrone sulfate was found to be similar to the change of estrone and estradiol-17β. The concentration of estrone sulfate was not higher than that of both estrogens in cattle.

Determination of Pentachlorophenol in Water and Soil by a Magnetic Particle-Based Enzyme Immunoassay

A competitive enzyme immunoassay using specific pentachlorophenol (PCP) antiserum covalently coupled to a magnetic particle solid phase has been developed for the detection of PCP in water and soil. The immunoassay allows the quantification of PCP from 100 ppt(parts per trillion, ng/L) in water and 100 ppb (parts per billion, mg/L) in soil. Spike recovery from water samples with no sample pretreatment and from various soil types following a simple extraction technique averaged 105% and 94%, respectively. The method compares favorably with GC/MS and HPLC measurements in water (r=0.980) and soil (r=0.996) samples.

A simple parameter extraction method for ultra-thin oxide MOSFETs

A simple parameter extraction technique is presented for ultra-thin oxide MOSFETs. The technique is based on a suitable MOSFET mobility model and extracts threshold voltage ( V t), mobility ( μ 0), and two mobility degradation parameters θ 1 and θ 2. It has been found that the extracted parameters accurately describe the measured current voltage characteristics for strong inversion.

Chemicals Generated During Oxygen-Organosolv Pulping of Wood

Abstract In this paper, we have characterized the black liquors from oxygen-organosolv pulping of Eucalyptus globulus wood in ethanol/water solutions (50:50, V/V) and acetic acid/water solutions (80:20, V/V). After pulp separation, the organic solvent has been distilled and recycled; the precipitated lignin has been recovered by filtration. The degradation products in solution have been easily separated by simple extraction techniques. Five main groups of compounds have been isolated: solid lignin (11–12% o.d.w.), sugars (10–17% o.d.w.), aliphatic acids (12,5%), aromatic acids (2% o.d.w.) and low molecular weight phenols (1% o.d.w.). Most of these compounds were identified by HPLC and GC. Solid lignins have been analyzed by FTIR and 13C NMR spectroscopy. It has been concluded that oxygen-organosolv pulping process can be a new and interesting way for pulp preparation with little pollution and possibility of total biomass recovery; alternatively, it can be used for the fractionation and valorization of the...

The Use of Sulphur Hexafluoride as a Conservative Tracer in Saturated Sandy Media

AbstractSulphur hexafluoride (SF6), a volatile, nontoxic, inorganic compound, behaved identically to bromide in a laboratory column tracer experiment with saturated sandy media. A simple system was used to achieve an SF6 injection concentration of approximately 7 mg/1, roughly 25% of its solubility. While this system requires more equipment and time than that involved in preparing ionic tracer solutions, certain benefits are realized. The detection limit for SF6 was approximately 5 μg/l using a simple headspace extraction technique and a gas Chromatograph with an electron capture detector. Thus, the tracer could be followed for a three order of magnitude decrease in concentration. For similar resolution, bromide had to be injected at a concentration over 1000 mg/1 (typical detection limit approximately 0.5 mg/1). When the required higher concentrations of the ionic tracers may lead to significant geochemical changes or density effects, SF6 may be the preferable tracer. Furthermore, unlike ionic tracers, the highly volatile SF6 may be readily removed from water. High volatility does, however, require that some care be taken to limit the potential loss of mass during injection, sampling, and analysis. Since others are developing procedures for analyzing SF6 in ground water with extremely low detection limits (on the order of 1 ng/1), it appears likely that measurable concentrations could range over six to seven orders of magnitude. This range is considerably wider than typically possible with ionic tracers, and may offer an important advantage in some applications.

抽出法およびＥＬＩＳＡ法を組み合わせた尿中ＩＬ‐６測定系の検討とメサンギウム増殖性腎炎患者における尿中ＩＬ‐６濃度の臨床的意義

The simple extraction technique of urinary IL-6 was developed, so urinary IL-6 levels can be measured by enzyme linked immunosorbent assay (ELISA) method without the influences of non-specific reactions and/or inhibitors. The urinary IL-6 levels in active stage of MesPGN cases were higher than those of remission stage of MesPGN cases, healthy cases and other glomerular disease cases. And in remission stage of MesPGN cases, urinary IL-6 levels were same level as in healthy cases.These data suggest that measurement of levels of urinary IL-6 is helpful for the diagnosis and evaluation of clinical activities of MesPGN.

Determination of Gluten in Foods Using a Monoclonal Antibody‐based Competition Enzyme Immunoassay

A sensitive competition enzyme‐immunoassay for quantification of gluten in foods was developed, using horseradish peroxidase‐labelled monoclonal antibodies. Selected antibodies specific for wheat omega‐gliadin components were used, and these antibodies bound proteins from the related cereals, rye and barley, which are also toxic to individuals with gluten‐intolerance (coeliac disease). Binding of these antibodies was not inhibited by heating of gluten during cooking or baking and the assay did not detect cereals not toxic in coeliac disease, such as maize or rice. Gluten could be quantified at higher levels in meat products or in cereal products such as flours or baked goods. Results were not affected by wheat variety. Quantitiative results could be obtained using simple extraction techniques and solvents (40% or 70% ethanol). Detection of gluten was quantitative in a wide range of foods, except for certain products containing gluten proteins that had been subjected to severe heat, enzymic or chemical tre...

A purification method for apolipoprotein A-I and A-II

Apolipoproteins A-I and A-II were isolated from precipitates obtained by cold ethanol fractionation of human plasma. The starting material used in this report was precipitate B of the Kistler and Nitschmann method which corresponds approximately to fraction III of the Cohn and Oncley procedure. Through the use of urea, chloroform, and ethanol in appropriate concentrations, apolipoproteins A-I and A-II were isolated by a simple extraction technique avoiding time-consuming ultracentrifugation. Starting from 10 g of centrifuged precipitate B, approximately 100 mg of apolipoprotein A-I and 10 mg of apolipoprotein A-II were obtained. When incubated with normal human or rabbit plasma, both apolipoproteins were readily incorporated into high-density lipoproteins. Apolipoprotein A-I obtained by the cold ethanol method activated lecithin-cholesterol acyltransferase to the same extent as apolipoprotein A-I prepared by the classical flotation method. Apolipoprotein A-II had no such properties by itself, but was capable of potentiating lecithin-cholesterol acyltransferase activity of apolipoprotein A-I.

Hepatic microsomal 4,5,6-trichloroguaiacol glucuronidation in five species of fish

Abstract 1. 1. Hepatic microsomal UDP glucuronyl transferase activity towards 4,5,6-trichloroguaiacol was characterized in five species of fish. The simple extraction technique used to determine glucuronidation rates was sufficiently accurate, as judged by high pressure liquid chromatography. 2. 2. UDP glucuronyl transferase activities were found to vary considerably between fish species. The level of UDP glucuronyl transferase activity in rainbow trout is among the highest in vitro conjugating activities reported in fish. 3. 3. Intraperitoneal injection of β-naphthoflavone resulted in an almost doubling of the UDP glucuronyl transferase activity in rainbow trout.

Extraction from Natural Planktonic Microorganisms of DNA Suitable for Molecular Biological Studies

We developed a simple technique for the high-yield extraction of purified DNA from mixed populations of natural planktonic marine microbes (primarily bacteria). This is a necessary step for several molecular biological approaches to the study of microbial communities in nature. The microorganisms from near-shore marine and brackish water samples, ranging in volume from 8 to 40 liters, were collected on 0.22-mum-pore-size fluorocarbon-based filters, after prefiltration through glass fiber filters, to remove most of the eucaryotes. DNA was extracted directly from the filters in 1% sodium dodecyl sulfate that was heated to 95 to 100 degrees C for 1.5 to 2 min. This procedure lysed essentially all the bacteria and did not significantly denature the DNA. The DNA was purified by phenol extraction, and precautions were taken to minimize shearing. Agarose gel electrophoresis showed that most of the final preparation had a large molecular size (>23 kilobase pairs). The DNA was sufficiently pure to allow complete digestion by the restriction endonuclease Sau3AI and ligation to vector DNA. In a sample in which the extracted DNA was quantified by binding to the dye Hoechst H33258, DNA was quantitatively extracted, and 45% of the initially extracted DNA was recovered after purification. Final yields were a few micrograms of DNA per liter of seawater and were roughly 25 to 50% of the total bacterial DNA in the sample. Alternatives to the initial harvest by filtration method, including continuous-flow centrifugation and thin-channel or hollow-fiber concentration followed by centrifugation, were less efficient than filtration in terms of both time and yield, largely because of the difficulty of centrifuging the very small bacteria typical of marine plankton. These methods were judged to be less appropriate for studies of natural populations as they impose a strong selection for the larger bacteria.

The analysis of several nonopiate narcotic analgesics and cocaine in serum using high-performance liquid chromatography.

This paper describes a procedure for the quantitative determination of methadone, meperidine, normeperidine, pentazocine, propoxyphene, norpropoxyphene, and dextromoramide in serum down to levels of 10 micrograms/L and of cocaine down to 25 micrograms/L. The procedure involves a simple extraction technique and high-performance liquid chromatography and is suitable for use in overdose drug screening, forensic toxicology, therapeutic drug monitoring, and pharmacokinetic studies.

A Simplified Analytical Procedure for the Determination of Diazepam in Intravenous Admixtures

Abstract A Simplified gas-Chromatographic technique was developed for the determinatilon of diazepam in intravenous admixtures. Aliquots of a methanolic solution of diazepam were further diluted in various aqueous vehicles: double-distilled water, 5% dextrose in water, 0.9% sodium chloride injection, Lactated Ringer's injection, and Ringer's injection. The assay procedure consisted of a simple extraction technique from the aqueous system into an nbutyl acetate phase using prazepam as the internal standard, peak-height ratios of diazepam:prazepam from the chromatograms were then plotted against the chromatograms were then plotted agaisnt theoretical aqueous diazepam concentra tions. The y-intercept and correlation coefficient of the data were also determined. Results of the study show that the diazepam:prazepam peakheight ratios exhibited consistent correlation coefficients in the five fluids studied. The retention time for diazepam was about 7.5 minutes, while prazepam had a retention time of 12 minutes.

Intraalveolar transplantation of teeth with crown-root fractures

Intraalveolar transplantation using a simple extraction technique with extrusion of the root sufficiently to allow crown preparation was performed in 23 cases of crown-root fractures. A normal periodontal membrane was present after three months in all cases. Signs of superficial root resorption were observed in two cases, and small periapical radiolucencies were seen in another two, probably as a reaction to the presence of excess root-filling material. Minor remodeling of the marginal bone adjacent to the extruded roots was observed in eight cases.

A simple and highly sensitive radioimmunoassay for 8-arginine vasopressin in human plasma using a reversed-phase C18 silica column

A highly sensitive and simple radioimmunoassay for the measurement of 8-arginine vasopressin (AVP) in human plasma has been developed. The dose response curve ranges from 0.025 to 8 pg/tube. This simple extraction technique employing an ODS C18 column recovered 87.1 +/- 10.4 (mean +/- SD)% of AVP in the range of 1-10 pg/ml added to 0.5 ml plasma. Determination of AVP in each fraction of plasma, which was gel-filtrated through a Sephadex G25 (1 X 25 cm), revealed that the fraction of plasma AVP was superimposed on that of authentic AVP, and interference of non-specific substances was completely eliminated by an ODS C18 column. Using the assay, 13 of 16 patients with diabetes insipidus (DI) showed plasma AVP concentrations ranging from 0.03 to 0.21 pg/ml, and the other 3 patients had less than 0.03 pg/ml. The AVP concentrations of DI were clearly distinguished from those obtained in normal subjects (0.30-4.20 pg/ml, n = 65). The within and between assay variability was about 10% each. Plasma AVP concentrations (mean +/- SD) of normal subjects (n = 6) standing, sitting, and supine after an overnight of fluid deprivation were 2.41 +/- 1.15, 1.95 +/- 0.85 and 0.97 +/- 0.48 pg/ml (30 min after) respectively. Plasma AVP concentrations of normal subjects (n = 6) after water load (20 ml/kg wt) were clearly reduced from 1.89 +/- 1.00 (before) to 0.42 +/- 0.21 (standing for 60 min) and also from 0.89 +/- 0.41 to 0.40 +/- 0.22 pg/ml (supine for 60 min).

Electrophoretic extraction-concentration of ribonucleic acid from agarose-acrylamide composite gels

A simple technique for the electrophoretic extraction of RNA, under constant monitoring by bromphenol blue line, in a concentrated form from agarose-acrylamide composite gels run according to A. C. Peacock and C. W. Dingman, ( Biochemistry 7, 668–674, (1968)) has been developed. Typically, the extraction time from 5 gel slices/tube containing 56 μg of RNA was 3.5 h, and the maximum concentration of the recovered RNA was 0.37 mg/ml with a total recovery of more than 90%. The desired scale can be adjusted by manipulating the number of tubes or number of slices.