The limit of detection of amosite in two forms of calcium silicate matrix

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

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Position Paper on Treatment of Hepatitis C in Romania, 2017. Part One

Journal of Gastrointestinal and Liver Diseases ◽

10.15403/jgld.2014.1121.262.rom ◽

2017 ◽

Vol 26 (2) ◽

pp. 171-181 ◽

Cited By ~ 2

Author(s):

Liana Gheorghe ◽

Ioan Sporea ◽

Speranţa Iacob ◽

Roxana Şirli ◽

Anca Trifan ◽

...

Keyword(s):

Hepatitis C Virus ◽

Liver Disease ◽

Hepatitis C ◽

Limit Of Detection ◽

Position Paper ◽

Hcv Infection ◽

Fixed Dose ◽

Diagnostic Tools ◽

End Stage Liver Disease ◽

End Stage

Background & Aims: Hepatitis C Virus (HCV) infection is a common condition with endemic prevalence in some areas of the world. In Romania, the mean prevalence is about 3%. New treatments became available on the market in recent years and new drugs are in the pipeline. A re-evaluation of HCV therapy was considered mandatory. The Romanian Society of Gastroenterology and Hepatology undertook this task for the practitioners of this country.Methodology: A group of recognized experts was created who screened the available literature and the major available guidelines. A list of items requiring attention has been created. These items were discussed and rated. Decisions were taken by consensus.Recommendations: We present here the first of the two parts of our Society’s recommendations for chronic HCV infection treatment. An agreement was reached regarding the diagnostic tools, the assessment of severity and the up-dated therapy schedules.Conclusions: This Position Paper represents a guide for the assessment and the therapy of HCV infection. The recommendations are in concordance with other guidelines but are applied to the real-life conditions in this country.Abbreviations: DAAs: Direct-acting antivirals; DDIs: Drug-drug interactions; ESLD: End-stage liver disease; ESRD: End-stage renal disease; eGFR: Estimated glomerular filtration rate; EASL: European Association for the Study of the Liver; EMA: European Medicines Agency; FDA: US Food and Drug Administration; FDC: Fixed-dose combination; GT: Genotype; GRADE: Grading of Recommendations Assessment, Development and Evaluation; HCV: Hepatitis C virus; HCC: Hepatocellular carcinoma; LT: Liver transplantation; LLD: Lower limit of detection; MELD score: Mayo-Clinic End-Stage Liver Disease score; ANMDM: National Agency of Medicines and Medical Devices; PPIs: Proton pump inhibitors; PWID: People who inject drugs; RCT: Randomized controlled trial; RDT: Rapid diagnostic test; RAS: Resistance-associated substitution; SRGH: Romanian Society of Gastroenterology and Hepatology; SAE: serious adverse events; SPC: Summary of Product Characteristics; SVR: Sustained virologic response.

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Development and Validation of A Reversed Phase-High Performance Liquid Chromatography Method for the Quantitative Estimation of Ramipril Drug Content from Formulated Dosage Form

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v6i3.8890 ◽

2016 ◽

Vol 6 (3) ◽

Author(s):

Raju Chandra ◽

Manisha Pant ◽

Harchan Singh ◽

Deepak Kumar ◽

Ashwani Sanghi

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Active Ingredient ◽

High Performance ◽

Limit Of Detection ◽

Quantitative Estimation ◽

Reversed Phase ◽

Uv Detector ◽

Chromatography Method ◽

Drug Content

A reliable and reproducible reversed-phase high performance liquid chromatography (RP-HPLC) was developed for the quantitative determination of Remipril drug content from marketed bulk tablets. The active ingredient of Remipril separation achieved with C18 column using the methanol water mobile phase in the ratio of 40:60 (v/v). The active ingredient of the drug content quantify with UV detector at 215 nm. The retention time of Remipril is 5.63 min. A good linearity relation (R2=0.999) was obtained between drug concentration and average peak areas. The limit of detection and limit of quantification of the instrument were calculated 0.03 and 0.09 µg/mL, respectively. The accuracy of the method validation was determined 102.72% by recoveries method.

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Spectrophotometeric Determination of Trifluoperazine HCL in Pure Forms and Pharmaceutical Preperations

International Journal of Pharmaceutical and Clinical Research ◽

10.25258/ijpcr.v9i5.8593 ◽

2017 ◽

Vol 9 (5) ◽

Author(s):

Mohammad Hamzah Hamzah ◽

Rawa M M Taqi ◽

Muna M. Hasan ◽

Raid J. M. Al-Timimi

Keyword(s):

Standard Method ◽

Limit Of Detection ◽

Molar Absorptivity ◽

Dosage Forms ◽

Oxidizing Agent ◽

Optimum Conditions ◽

Limit Of Quantification ◽

Cerium Ion ◽

Blank Solution

A simple and accurate spectrophotometric method for the determination of Trifluoperazine HCl in pure and dosage forms was developed. The method is based on the reaction between Trifluoperazine HCl and p-chloroaniline in the presence of cerium ion as oxidizing agent which lead to the formation of violate color product that absorbed at a maximum wavelength 570nm while the blank solution was pink. Under the optimum conditions a linear relationship between the intensity and concentration of TRF in the range 4-50μg/ml was obtained . The molar absorptivity 3.74×103 L.mol-1.cm-1 , Limit of detection (2.21μg/ml), while limit of quantification was 7.39μg/ml. The proposed analytical method was compared with standard method using t-test and F-test , the obtained results shows there is no significant differences between proposed method and standard method. Based on that the proposed method can be used as an alternative method for the determination of TRF in pure and dosage forms.

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Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

10.26434/chemrxiv.5662315.v1 ◽

2017 ◽

Author(s):

Bo Tian ◽

Peter Svedlindh ◽

Mattias Strömberg ◽

Erik Wetterskog

Keyword(s):

Magnetic Nanoparticles ◽

Ferromagnetic Resonance ◽

Limit Of Detection ◽

Point Of Care ◽

Rolling Circle Amplification ◽

Resonance Field ◽

Isothermal Amplification ◽

Detection Sensitivity ◽

Serum Samples ◽

Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, i.e., rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg2P2O7 (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.

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Comparative analysis of luminescence Property of Tb3+and Er3+Activated Calcium Silicate Phosphor

International Journal of Computer Sciences and Engineering ◽

10.26438/ijcse/v6i10.108114 ◽

2018 ◽

Vol 6 (10) ◽

pp. 108-114

Author(s):

Shailendra Verma ◽

Anup Mishra ◽

Manmeet Bhuie ◽

Nirbhay K Singh

Keyword(s):

Comparative Analysis ◽

Calcium Silicate ◽

Luminescence Property ◽

Silicate Phosphor

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Skin exposure: requirements to methods determining active ingredient of pesticides in washings

Russian Journal of Occupational Health and Industrial Ecology ◽

10.31089/1026-9428-2018-9-43-48 ◽

2019 ◽

pp. 43-48

Author(s):

V. N. Rakitskii ◽

N. E. Fedorova ◽

I. V. Bereznyak ◽

N. G. Zavolokina ◽

L. P. Muhina

Keyword(s):

Lower Limit ◽

Limit Of Detection ◽

Solid Phase ◽

Absorbed Dose ◽

Ambient Air ◽

Safety Coefficient ◽

Limit Value ◽

Calculated Risk ◽

Nature Studies ◽

Active Substances

The article presents results of studies exemplified by diquat on analysis concerning inﬂuence of lower limit value of quantitative assessment in washing sample for safety coefficient in exposure and in absorbed dose, if acting substance is absent in workplace ambient air samples and in dermal washings of workers. To control diquat in dermal washings, there is a method based on ion-pair liquid chromatography with ultraviolet detection (working wavelength 310 nm). To concentrate sample, cartridges for solid-phase extraction, containing ion exchange sorbent (Oasis MCX 6cc/500 mg), are used. Lower limit of assessment in washing sample — 0,15 micrograms. Experimentally set washing completeness is within range of 80–92%, standard deviation of repetition is 7,0% at most. The method created was tested in nature studies determining dermal exposure in workers subjected to 5 various preparations based on diquat dibromide when used for surface spraying from tractor and from aircraft. For lower limit of detection in washing sample (0,15 micrograms/washing), calculated risk value of exposure varied within 0,26–0,36; risk of absorbed dose was low — 0,23 (the allowable one ≤1). Findings are that present measuring methods which provide lower limit of detection 1 and 5 micrograms in washing sample could result in unallowable risk establishment even with absence of the substance in all samples of workplace air and dermal washings. The calculation formula suggested enables to give theoretic basis for requirements to lower limit of detecting active substances in dermal washing samples for evaluating risk of pesticides use in agriculture.

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