scholarly journals The Application of a Cadmium Reducer and a Diazotisation Reaction for the Determination of Nitrate and Nitrite in Tobacco / Über die Anwendung des Cadmium-Reduktors und der Diazotierung zur Bestimmung von Nitrat und Nitrit im Tabak

1965 ◽  
Vol 3 (2) ◽  
Author(s):  
U. Dölberg
Keyword(s):  
Quantitative Analysis ◽  
Reduction Method ◽  
Limit Of Detection ◽  
Nitrate And Nitrite ◽  
Inferior Limit

AbstractNitrate is reduced by means of a cadmium reducer and spectrophotometrically determined in the form of nitrite by a diazotisation reaction. The results obtained by application of the described method to tobacco extracts correspond well to those resulting from the earlier described dimethylphenol procedure. Owing to its better sensitivity and specifity the reduction method is particularly suitable for the quantitative analysis of smallest amounts of nitrate. Quantities of 0.03 % of nitrate can be determined without difficulties. The inferior limit of detection is 0.001 %.

scholarly journals A Method for the Determination of Nicotine in Lung Tissue of Hamsters / Eine Methode zur Bestimmung des Nikotins in Hamsterlungen

1966 ◽  
Vol 3 (6) ◽  
Author(s):  
H. Elmenhorst
Keyword(s):  
Standard Deviation ◽  
Hydrochloric Acid ◽  
Lung Tissue ◽  
Coefficient Of Variation ◽  
Steam Distillation ◽  
Analytical Procedure ◽  
Limit Of Detection ◽  
Experimental Animals ◽  
Inferior Limit

AbstractA method for the determination of nicotine in lung tissue is presented. The nicotine is extracted from homogenized lung tissue by means of a mixture of hydrochloric acid and methanol. It is then spectrophotometrically determined after the disturbing accompanying substances have been eliminated by a preliminary acid steam distillation. The method's inferior limit of detection is 40 µg of nicotine contained in 3 lungs, which corresponds to 17.7 µg of nicotine per gramme of lung tissue. In the case of nicotine contents of 50 µg per analytical procedure the standard deviation of the method was found to be 1.7 µg, and the resulting coefficient of variation was calculated to be 3.4 %. The procedure is simple and therefore suitable for the study of numerous samples. The exposure of hamsters to inhaled raw cigarette smoke revealed that the nicotine content of lungs of experimental animals augments with the number of burnt cigarettes and the duration of inhalation. The reproducibility of Dontenwill's inhalation procedure was tested and proved to be satisfactory. The coefficient of variation within two series of inhalation experiments was found to be between 4.1 and 5.2 %

scholarly journals Quantitative Analysis of Three Chiral Pesticide Enantiomers by High-Performance Column Liquid Chromatography

2008 ◽  
Vol 91 (5) ◽  
pp. 1007-1012 ◽  
Author(s):  
Peng Wang ◽  
Donghui Liu ◽  
Xu Gu ◽  
Shuren Jiang ◽  
Zhiqiang Zhou
Keyword(s):  
Quantitative Analysis ◽  
Quantitative Determination ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Optical Purity ◽  
High Performance Liquid Chromatographic ◽  
Precision Data ◽  
Chiral Pesticides

Abstract Methods for the enantiomeric quantitative determination of 3 chiral pesticides, paclobutrazol, myclobutanil, and uniconazole, and their residues in soil and water are reported. An effective chiral high-performance liquid chromatographic (HPLC)-UV method using an amylose-tris(3,5-dimethylphenylcarbamate; AD) column was developed for resolving the enantiomers and quantitative determination. The enantiomers were identified by a circular dichroism detector. Validation involved complete resolution of each of the 2 enantiomers, plus determination of linearity, precision, and limit of detection (LOD). The pesticide enantiomers were isolated by solvent extraction from soil and C18 solid-phase extraction from water. The 2 enantiomers of the 3 pesticides could be completely separated on the AD column using n-hexane isopropanol mobile phase. The linearity and precision results indicated that the method was reliable for the quantitative analysis of the enantiomers. LODs were 0.025, 0.05, and 0.05 mg/kg for each enantiomer of paclobutrazol, myclobutanil, and uniconazole, respectively. Recovery and precision data showed that the pretreatment procedures were satisfactory for enantiomer extraction and cleanup. This method can be used for optical purity determination of technical material and analysis of environmental residues.

scholarly journals Using Cholinesterases and Immobilized Luminescent Photobacteria for the Express-Analysis of Mycotoxins and Estimating the Efficiency of Their Enzymatic Hydrolysis

Toxins ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 34
Author(s):  
Elena Efremenko ◽  
Olga Maslova ◽  
Nikolay Stepanov ◽  
Anvar Ismailov
Keyword(s):  
Quantitative Analysis ◽  
Ochratoxin A ◽  
Limit Of Detection ◽  
Scientific Practice ◽  
Rapid Analysis ◽  
Organophosphorus Hydrolase ◽  
Enzyme Efficiency ◽  
Express Analysis ◽  
First Time

Novel sensitive analytical agents that can be used for simple, affordable, and rapid analysis of mycotoxins are urgently needed in scientific practice, especially for the screening of perspective bio-destructors of the toxic contaminants. We compared the characteristics of a rapid quantitative analysis of different mycotoxins (deoxynivalenol, ochratoxin A, patulin, sterigmatocystin, and zearalenone) using acetyl-, butyrylcholinesterases and photobacterial strains of luminescent cells in the current study. The best bioindicators in terms of sensitivity and working range (μg/mL) were determined as follows: Photobacterium sp. 17 cells for analysis of deoxynivalenol (0.8–89) and patulin (0.2–32); Photobacterium sp. 9.2 cells for analysis of ochratoxin A (0.4–72) and zearalenone (0.2–32); acetylcholinesterase for analysis of sterigmatocystin (0.12–219). The cells were found to be more sensitive than enzymes. The assayed strains of photobacterial cells ensured 44%–83% lower limit of detection for deoxynivalenol and sterigmatocystin as compared to the previously known data for immobilized luminescent cells, and the range of working concentrations was extended by a factor of 1.5–3.5. Calibration curves for the quantitative determination of patulin using immobilized photobacteria were presented in this work for the first time. This calibration was applied to estimate the enzyme efficiency for hydrolyzing mycotoxins using zearalenone and His6-tagged organophosphorus hydrolase as examples.

scholarly journals Difluoroboron Curcumin Complex: A Study on Determination of Acidity Constants and Quantitative Analysis of Arsenic(III)

2021 ◽  
Vol 21 (5) ◽  
pp. 1271
Author(s):  
Nguyen Quoc Thang ◽  
Tran Nguyen Minh An ◽  
Le Thi Thanh Tran ◽  
Do Tam Nhan ◽  
Mai Ngoc Tan ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Boron Trifluoride ◽  
Dissociation Constants ◽  
Limit Of Detection ◽  
High Accuracy ◽  
The Other ◽  
Total Arsenic ◽  
Acidity Constants ◽  
Limit Of Quantification

In this study, the complex of difluoroboron, curcumin (BF2-Cur), has been synthesized and characterized via the combination of Boron trifluoride-diethyl etherate ((C2H5)2OBF3) and curcumin. However, the new dissociation constants, pKa1 and pKa2 of the BF2-Cur complex, have been indicted by the values of 8.44 ± 0.16 and 9.76 ± 0.13, respectively. On the other hand, the reagent was also used to determine As(III) in aqueous solutions by UV–Vis spectrophotometry. As a result, the method was validated for accuracy, precision, linearity, and sensitivity, and the linear range was from 1.0 to 25.0 µmol/L, with the linear regression, A = 0.0027 C + 0.0106, correlation coefficient R2 = 0.9969. Besides, the limit of detection (LOD) and limit of quantification (LOQ) were determined as 0.83 and 2.10 µmol/L, respectively. Thus, the developed method is successfully used for quantitative analysis of total arsenic in wastewater by reducing As(V) to As(III), then determining As(III) with high accuracy results.

scholarly journals Fast and sensitive method for phosphorus determination in dairy products

2021 ◽  
Author(s):  
Anna Gliszczyńska-Świgło ◽  
Iga Rybicka
Keyword(s):  
Quantitative Analysis ◽  
Dairy Products ◽  
Phosphorus Content ◽  
Limit Of Detection ◽  
Sustainable Chemistry ◽  
Limit Of Quantification ◽  
Molybdenum Blue ◽  
Phosphorus Determination ◽  
Sensitive Method

AbstractThe spectrophotometric molybdenum blue method for phosphorus determination was adapted to a multiwell plate format. The method was sensitive and allowed for the simultaneous determination of phosphorus in many samples. It was cheap and eco-friendly due to application of small volumes of reagents and, therefore, it meets the requirements for “green” or sustainable chemistry. The method’s limit of detection (LOD) is 0.37 μg/mL and its limit of quantification (LOQ) is 1.13 μg/mL. Its linearity is up to 30 μg of phosphorus/mL. The method was applied for the determination of phosphorus in 65 dairy products (yogurts, yogurt drinks, buttermilks, kefirs and homogenized cheeses) of strawberry, peach, forest fruits, vanilla and other flavours. The phosphorus content was 143–226 mg/100 g in flavoured yogurts, 78–204 mg/100 g in yogurt drinks, 89–218 mg/100 g in kefirs, around 195 mg/100 g in buttermilks, and 165–277 mg/100 g in homogenized cheeses. The presented method can be used in the routine quantitative analysis of the total phosphorus content in dairy products.

An Improved Quantitative Image Analyser

1977 ◽  
Vol 35 ◽  
pp. 226-227
Author(s):  
J.P. Fallon ◽  
P.J. Gregory ◽  
C.J. Taylor
Keyword(s):  
Feature Extraction ◽  
Quantitative Analysis ◽  
Frequency Content ◽  
General Sense ◽  
Physical Measurements ◽  
Quantitative Image ◽  
Image Analyser ◽  
Automatic Methods ◽  
Quantitative Results

Quantitative image analysis systems have been used for several years in research and quality control applications in various fields including metallurgy and medicine. The technique has been applied as an extension of subjective microscopy to problems requiring quantitative results and which are amenable to automatic methods of interpretation.Feature extraction. In the most general sense, a feature can be defined as a portion of the image which differs in some consistent way from the background. A feature may be characterized by the density difference between itself and the background, by an edge gradient, or by the spatial frequency content (texture) within its boundaries. The task of feature extraction includes recognition of features and encoding of the associated information for quantitative analysis.Quantitative Analysis. Quantitative analysis is the determination of one or more physical measurements of each feature. These measurements may be straightforward ones such as area, length, or perimeter, or more complex stereological measurements such as convex perimeter or Feret's diameter.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

1973 ◽  
Vol 72 (4) ◽  
pp. 714-726 ◽  
Author(s):  
A. Burger ◽  
B. Miller ◽  
C. Sakoloff ◽  
M. B. Vallotton
Keyword(s):  
Ionic Strength ◽  
Limit Of Detection ◽  
Improved Method ◽  
Accuracy Of Measurement ◽  
Tracer Amount ◽  
The Mean ◽  
Physiological Values ◽  
Hyperthyroid Patients ◽  
Solvent Blank

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.

Spectrophotometeric Determination of Trifluoperazine HCL in Pure Forms and Pharmaceutical Preperations

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.

Application of EDS Technique for OSP Film Thickness Measurement

2006 ◽  
Author(s):  
Prong Kongsubto ◽  
Sirarat Kongwudthiti
Keyword(s):  
Thin Film ◽  
Quantitative Analysis ◽  
Joint Strength ◽  
Critical Factor ◽  
Thickness Measurement ◽  
Ic Manufacturing ◽  
And Control ◽  
Film Thickness Measurement ◽  
Non Destructive

Abstract Organic solderability preservatives (OSPs) pad is one of the pad finishing technologies where Cu pad is coated with a thin film of an organic material to protect Cu from oxidation during storage and many processes in IC manufacturing. Thickness of OSP film is a critical factor that we have to consider and control in order to achieve desirable joint strength. Until now, no non-destructive technique has been proposed to measure OSP thickness on substrate. This paper reports about the development of EDS technique for estimating OSP thickness, starting with determination of the EDS parameter followed by establishing the correlation between C/Cu ratio and OSP thickness and, finally, evaluating the accuracy of the EDS technique for OSP thickness measurement. EDS quantitative analysis was proved that it can be utilized for OSP thickness estimation.

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