Rapid and reliable determination of the halogenating peroxidase activity in blood samples

Abstract We compared four methods for determination of glutathione peroxidase (EC 1.11.1.9) activity, using blood samples from 52 healthy volunteers. Two methods depended on direct assay of the amount of glutathione remaining at specific time intervals; the two indirect methods involved measuring the rate of disappearance of NADPH. We assessed the precision and reproducibility of each method. One of the indirect assays proved to be far superior to the other methods. Results of each of the methods were correlated with one another. We present the normal reference intervals for glutathione peroxidase activity for all four methods.

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A panel of mono- and dinucleotide microsatellite markers is required for reliable determination of the MSI status in colorectal cancer

Gastroenterology ◽

10.1016/s0016-5085(01)82977-2 ◽

2001 ◽

Vol 120 (5) ◽

pp. A599-A599

Author(s):

C ARNOLD ◽

A GOEL ◽

J CARETHERS ◽

L WASSERMAN ◽

C COMPTON ◽

...

Keyword(s):

Colorectal Cancer ◽

Microsatellite Markers ◽

Reliable Determination

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Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v12i7.6703 ◽

2013 ◽

Vol 12 (7) ◽

pp. 460-465

Author(s):

Sameer Amereih ◽

Zaher Barghouthi ◽

Lamees Majjiad

Keyword(s):

Drinking Water ◽

Detection Limit ◽

Complex Formation ◽

Molar Absorptivity ◽

Colorimetric Determination ◽

Zirconium Complex ◽

Reliable Determination ◽

Percentage Recovery ◽

Quantitation Limit

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.

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Synthesis and solvatochromic studies of 2- amino-3-phenolazo1-(4-sulfophenyl)-3-methyi-5-pyrozolone and use it for the determination of trace amount of Nickel (II) in blood samples

International Journal of Bioassays ◽

10.21746/ijbio.2016.10.001 ◽

2016 ◽

Vol 5 (10) ◽

pp. 4920

Author(s):

Amar M. Ali ◽

Hussain. J. Mohammed*

Keyword(s):

Stability Constant ◽

Trace Amount ◽

Benzenesulfonic Acid ◽

Determination Method ◽

Blood Samples ◽

Determination Of Nickel ◽

Normal Human ◽

The Stability ◽

Normal Human Blood

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood.

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Determination of 19 Psychoactive Substances in Premortem and Postmortem Whole Blood Samples Using Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

Separations ◽

10.3390/separations8060078 ◽

2021 ◽

Vol 8 (6) ◽

pp. 78

Author(s):

Sevasti Karampela ◽

Jessica Smith ◽

Irene Panderi

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Formic Acid ◽

Whole Blood ◽

High Performance ◽

Tandem Mass ◽

Psychoactive Substances ◽

Blood Samples ◽

Whole Blood Samples

An ever-increasing need exists within the forensic laboratories to develop analytical processes for the qualitative and quantitative determination of a broad spectrum of new psychoactive substances. Phenylethylamine derivatives are among the major classes of psychoactive substances available on the global market and include both amphetamine analogues and synthetic cathinones. In this work, an ultra-high-performance liquid chromatography-positive ion electrospray ionization tandem mass spectrometric method (UHPLC-ESI-MS/MS) has been developed and fully validated for the determination of 19 psychoactive substances, including nine amphetamine-type stimulants and 10 synthetic cathinone derivatives, in premortem and postmortem whole blood. The assay was based on the use of 1 mL premortem or postmortem whole blood, following solid phase extraction prior to the analysis. The separation was achieved on a Poroshell 120 EC-C18 analytical column with a gradient mobile phase of 0.1% formic acid in acetonitrile and 0.1% formic acid in water in 9 min. The dynamic multiple reaction monitoring used in this work allowed for limit of detection (LOD) and lower limit of quantitation (LOQ) values of 0.5 and 2 ng mL−1, respectively, for all analytes both in premortem and postmortem whole blood samples. A quadratic calibration model was used for the 12 quantitative analytes over the concentration range of 20–2000 ng mL−1, and the method was shown to be precise and accurate both in premortem and postmortem whole blood. The method was applied to the analysis of real cases and proved to be a valuable tool in forensic and clinical toxicology.

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Fast and Sensitive Determination of the Fungicide Carbendazim in Fruit Juices with an Immunosensor Based on White Light Reflectance Spectroscopy

Biosensors ◽

10.3390/bios11050153 ◽

2021 ◽

Vol 11 (5) ◽

pp. 153

Author(s):

Georgios Koukouvinos ◽

Chrysoula-Evangelia Karachaliou ◽

Ioannis Raptis ◽

Panagiota Petrou ◽

Evangelia Livaniou ◽

...

Keyword(s):

White Light ◽

Optical Biosensor ◽

Reflectance Spectroscopy ◽

Fruit Juices ◽

Sample Treatment ◽

Assay Sensitivity ◽

Reliable Determination ◽

Light Reflectance ◽

Sensitive Determination

Carbendazim is a systemic benzimidazole-type fungicide with broad-spectrum activity against fungi that undermine food products safety and quality. Despite its effectiveness, carbendazim constitutes a major environmental pollutant, being hazardous to both humans and animals. Therefore, fast and reliable determination of carbendazim levels in water, soil, and food samples is of high importance for both food industry and public health. Herein, an optical biosensor based on white light reflectance spectroscopy (WLRS) for fast and sensitive determination of carbendazim in fruit juices is presented. The transducer is a Si/SiO2 chip functionalized with a benzimidazole conjugate, and determination is based on a competitive immunoassay format. Thus, for the assay, a mixture of an in-house developed rabbit polyclonal anti-carbendazim antibody with the standards or samples is pumped over the chip, followed by biotinylated secondary antibody and streptavidin. The WLRS platform allows for real-time monitoring of biomolecular interactions carried out onto the Si/SiO2 chip by transforming the shift in the reflected interference spectrum caused by the immunoreaction to effective biomolecular adlayer thickness. The sensor is able to detect 20 ng/mL of carbendazim in fruit juices with high accuracy and precision (intra- and inter-assay CVs ≤ 6.9% and ≤9.4%, respectively) in less than 30 min, applying a simple sample treatment that alleviates any “matrix-effect” on the assay results and a 60 min preincubation step for improving assay sensitivity. Excellent analytical characteristics and short analysis time along with its small size render the proposed WLRS immunosensor ideal for future on-the-spot determination of carbendazim in food and environmental samples.

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Exploitation of HPLC Analytical Method for Simultaneous Determination of Six Principal Unsaturated Fatty Acids in Oviductus Ranae Based on Quantitative Analysis of Multi-Components by Single-Marker (QAMS)

Molecules ◽

10.3390/molecules26020479 ◽

2021 ◽

Vol 26 (2) ◽

pp. 479

Author(s):

Shihan Wang ◽

Yuanshuai Gan ◽

Hong Kan ◽

Xinxin Mao ◽

Yongsheng Wang

Keyword(s):

Fatty Acids ◽

Quantitative Analysis ◽

Unsaturated Fatty Acids ◽

Internal Standard ◽

Active Components ◽

Reliable Determination ◽

External Standard Method ◽

Single Marker ◽

Oviductus Ranae

As one of the featured products in northeast China, Oviductus Ranae has been widely used as a nutritious food, which contains a variety of bioactive unsaturated fatty acids (UFAs). It is necessary to establish a scientific and reliable determination method of UFA contents in Oviductus Ranae. In this work, six principal UFAs in Oviductus Ranae, namely eicosapentaenoic acid (EPA), linolenic acid (ALA), docosahexaenoic acid (DHA), arachidonic acid (ARA), linoleic acid (LA) and oleic acid (OA), were identified using UPLC-MS/MS. The UFAs identified in Oviductus Ranae were further separated based on the optimized RP-HPLC conditions. Quantitative analysis of multi-components by single-marker (QAMS) method was implemented in content determination of EPA, ALA, DHA, ARA and OA, where LA was used as the internal standard. The experiments based on Taguchi design verified the robustness of the QAMS method on different HPLC instruments and chromatographic columns. The QAMS and external standard method (ESM) were used to calculate the UFA content of 15 batches of Oviductus Ranae samples from different regions. The relative error (r < 0.73%) and cosine coefficient showed that the two methods obtained similar contents, and the method validations met the requirements. The results showed that QAMS can comprehensively and effectively control the quality of UFAs in Oviductus Ranae which provides new ideas and solutions for studying the active components in Oviductus Ranae.

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Does the manual insertion torque of smartpegs affect the outcome of implant stability quotients (ISQ) during resonance frequency analysis (RFA)?

International Journal of Implant Dentistry ◽

10.1186/s40729-019-0195-1 ◽

2019 ◽

Vol 5 (1) ◽

Cited By ~ 1

Author(s):

Ingrid Kästel ◽

Giles de Quincey ◽

Jörg Neugebauer ◽

Robert Sader ◽

Peter Gehrke

Keyword(s):

Resonance Frequency ◽

Frequency Analysis ◽

Insertion Torque ◽

Resonance Frequency Analysis ◽

Implant Stability ◽

Reliable Determination ◽

Torque Values ◽

Finger Pressure

Abstract Background There is disagreement about the optimal torque for tightening smartpegs for resonance frequency analysis (RFA). Subjective finger pressure during hand tightening could affect the reliability of the resulting values. The aim of the current study was therefore to assess whether or not the insertion torque of a smartpeg magnetic device influences the implant stability quotient (ISQ) value during RFA. Methods Thirty self-tapping screw implants (XiVE S, Dentsply Sirona Implants, Bensheim, Germany) with a diameter of 3.8 mm and a length of 11 mm were inserted in three cow ribs with a bone quality of D1. The RFA value of each implant was measured (Ostell, FA W&H Dentalwerk, Bürmoos, Austria) in two orthogonal directions (mesial and buccal) after tightening the corresponding smartpeg type 45 with a mechanically defined value of 5 Ncm (Meg Torq device, Megagen, Daegu, South Korea) (test). Additionally, 4 different examiners measured the RFA after hand tightening the smartpegs, and the results were compared (control). Insertion torque values were determined by measuring the unscrew torque of hand seated smartpegs (Tohnichi Manufacturing Co. Ltd, Tokyo, Japan). Results The ISQ values varied from 2 to 11 Ncm by hand tightening and from 2 to 6 Ncm by machine tightening. The comparison of hand and machine tightening of smartpegs displayed only minor differences in the mean ISQ values with low standard deviations (mesial 79.76 ± 2,11, buccal 77.98 ± 2,) and no statistical difference (mesial p = 0,343 and buccal p = 0,890). Conclusions Manual tightening of smartpeg transducers allows for an objective and reliable determination of ISQ values during RFA.

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Validation of two UHPLC-MS/MS methods for fast and reliable determination of quinolone residues in honey

Food Additives & Contaminants Part A ◽

10.1080/19440049.2021.1881621 ◽

2021 ◽

pp. 1-13

Author(s):

Akyıldız İsmail Emir ◽

Yetimoğlu Kök Ece ◽

Raday Sinem ◽

Acar Sezer ◽

Erdem Özge

Keyword(s):

Reliable Determination

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Proteomic Determination of Low-Molecular-Weight Glutenin Subunit Composition in Aroona Near-Isogenic Lines and Standard Wheat Cultivars

International Journal of Molecular Sciences ◽

10.3390/ijms22147709 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7709

Author(s):

Kyoungwon Cho ◽

You-Ran Jang ◽

Sun-Hyung Lim ◽

Susan B. Altenbach ◽

Yong Q. Gu ◽

...

Keyword(s):

Molecular Weight ◽

Allelic Variation ◽

Reversed Phase ◽

Glutenin Subunit ◽

Low Molecular Weight ◽

Near Isogenic Lines ◽

Wheat Cultivars ◽

Reliable Determination ◽

Isogenic Lines

The low-molecular weight glutenin subunit (LMW-GS) composition of wheat (Triticum aestivum) flour has important effects on end-use quality. However, assessing the contributions of each LMW-GS to flour quality remains challenging because of the complex LMW-GS composition and allelic variation among wheat cultivars. Therefore, accurate and reliable determination of LMW-GS alleles in germplasm remains an important challenge for wheat breeding. In this study, we used an optimized reversed-phase HPLC method and proteomics approach comprising 2-D gels coupled with liquid chromatography–tandem mass spectrometry (MS/MS) to discriminate individual LMW-GSs corresponding to alleles encoded by the Glu-A3, Glu-B3, and Glu-D3 loci in the ‘Aroona’ cultivar and 12 ‘Aroona’ near-isogenic lines (ARILs), which contain unique LMW-GS alleles in the same genetic background. The LMW-GS separation patterns for ‘Aroona’ and ARILs on chromatograms and 2-D gels were consistent with those from a set of 10 standard wheat cultivars for Glu-3. Furthermore, 12 previously uncharacterized spots in ‘Aroona’ and ARILs were excised from 2-D gels, digested with chymotrypsin, and subjected to MS/MS. We identified their gene haplotypes and created a 2-D gel map of LMW-GS alleles in the germplasm for breeding and screening for desirable LMW-GS alleles for wheat quality improvement.

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