scholarly journals Glycohemoglobin filter assay for doctors’ offices based on boronic acid affinity principle

1997 ◽  
Vol 43 (12) ◽  
pp. 2390-2396 ◽  
Author(s):  
Frank Frantzen ◽  
Kjersti Grimsrud ◽  
Dag-Erik Heggli ◽  
Arne Ludvig Faaren ◽  
Trond Løvli ◽  
...  
Keyword(s):  
Acid Derivative ◽  
Boronic Acid ◽  
Correlation Coefficients ◽  
Water Soluble ◽  
Precipitation Method ◽  
Hb A1c ◽  
Total Hemoglobin ◽  
Filter Assay ◽  
Unique Application

Abstract We present a new filter assay for the determination of glycohemoglobin as a unique application of the boronic acid affinity principle. With the use of a water-soluble blue-colored boronic acid derivative and a specific precipitation method for hemoglobin, total hemoglobin including bound boronic acid is precipitated and collected on a filter strip before quantification. Hemoglobin and boronic acid are quantified by a dual-wavelength reflectometric measurement, and the result is reported directly as percent glycohemoglobin. The test is simple, quick, and designed as a doctors’ office test for the monitoring and management of diabetes. The imprecision of the assay is <4% over the range 3–18% Hb A1c, and the method is linear up to at least 20% Hb A1c. Comparisons with four well-established glycohemoglobin methods yielded correlation coefficients ranging from 0.94 to 0.99, with slopes from 0.94 to 1.01.

scholarly journals Non-separation assay for glycohemoglobin

1998 ◽  
Vol 44 (6) ◽  
pp. 1302-1308 ◽  
Author(s):  
Stuart Blincko ◽  
Raymond Edwards
Keyword(s):  
Diabetes Mellitus ◽  
Acid Derivative ◽  
Fluorescence Intensity ◽  
Boronic Acid ◽  
Total Hemoglobin ◽  
Established Procedure ◽  
Hemoglobin A ◽  
Light Absorbance

Abstract The determination of glycohemoglobin [HbA1c, HbA1, or total glycohemoglobin (GHb)] has become an established procedure in the management of diabetes mellitus. Here, we describe the development of a simple, fluorescence, non-separation assay for the percentage of GHb (%GHb). The fluorescence of an eosin-boronic acid derivative when it was mixed with hemolysates of unwashed erythrocytes was quenched in proportion to the percentage of glycohemoglobin. Measurement of the fluorescence intensity gave an estimate of GHb in the sample, and measurement of light absorbance gave an estimate of total hemoglobin. A combination of the two measurements gave the assay response. Comparison with HPLC (Menarini-Arkray HA-8140 fully automated analyzer) for the percentage of HbA1 (%HbA1) gave %GHb(NETRIA) = 1.1(SD ±0.03)%HbA1 +0.6(SD ±0.3), Sy‖x = 0.821, r = 0.972, n = 80; comparison for HbA1c gave %GHb(NETRIA) = 1.3(SD ±0.04)%HbA1c + 1.8(SD ±0.3), Sy‖x = 0.813, r = 0.973, n = 80. Precision, estimated as the percentage of the CV of the %GHb assay results, was <2% (intraassay, range 5–22% GHb) and <4.2% (interassay, range 4–16% GHb). Dilution of a high-percentage GHb sample lysate showed that the assay was linear, and addition of glucose (60 mmol/L), bilirubin (250 μmol/L), and triglycerides (14 mmol/L) to low, medium, and high %GHb samples showed no clinical interference in assay results.

scholarly journals Chemometric Methods for the Simultaneous Determination of Some Water-Soluble Vitamins

2011 ◽  
Vol 94 (2) ◽  
pp. 467-481 ◽  
Author(s):  
Abdel-Maaboud I Mohamed ◽  
Horria A Mohamed ◽  
Niveen A Mohamed ◽  
Marwa R El-Zahery
Keyword(s):  
Correlation Coefficients ◽  
Water Soluble ◽  
Multivariate Methods ◽  
Linear Calibration ◽  
Principal Components Regression ◽  
Regression Methods ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
Accuracy And Precision

Abstract Two spectrophotometric methods, derivative and multivariate methods, were applied for the determination of binary, ternary, and quaternary mixtures of the water-soluble vitamins thiamine HCl (I), pyridoxine HCl (II), riboflavin (III), and cyanocobalamin (IV). The first method is divided into first derivative and first derivative of ratio spectra methods, and the second into classical least squares and principal components regression methods. Both methods are based on spectrophotometric measurements of the studied vitamins in 0.1 M HCl solution in the range of 200500 nm for all components. The linear calibration curves were obtained from 2.590 g/mL, and the correlation coefficients ranged from 0.9991 to 0.9999. These methods were applied for the analysis of the following mixtures: (I) and (II); (I), (II), and (III); (I), (II), and (IV); and (I), (II), (III), and (IV). The described methods were successfully applied for the determination of vitamin combinations in synthetic mixtures and dosage forms from different manufacturers. The recovery ranged from 96.1 1.2 to 101.2 1.0 for derivative methods and 97.0 0.5 to 101.9 1.3 for multivariate methods. The results of the developed methods were compared with those of reported methods, and gave good accuracy and precision.

scholarly journals Multiple-Reaction Monitoring Tandem Mass Method for Determination of Phenolics and Water-Soluble Vitamins in Eccoilopus formosanus

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3632
Author(s):  
Ho-Shin Huang ◽  
Hsu-Sheng Yu ◽  
Chia-Hung Yen ◽  
Ean-Tun Liaw
Keyword(s):  
Multiple Reaction Monitoring ◽  
Correlation Coefficients ◽  
Ion Source ◽  
Water Soluble ◽  
Reaction Monitoring ◽  
Limit Of Quantification ◽  
Cereal Grain ◽  
Relative Standard ◽  
Qualitative Determination

This study established a validated method for the quantitative and qualitative determination of eight signature compounds in Eccoilopus formosanus. We used multiple-reaction monitoring scanning for quantification, and switched the electrospray ion source polarity between positive and negative modes in a single chromatographic run. The precursor-to-product ion transitions were m/z 355/163, m/z 181/163, m/z 265/122, m/z 269/117, m/z 170/152, m/z 377.2/180.7, m/z 169/124.8 and m/z 193/134 for chlorogenic acid, caffeic acid, thiamine, apigenin, pyridoxamin, riboflavin, gallic acid and ferulic acid, respectively. The developed method was also validated for accuracy, precision and limit of quantification. In this method, eight compounds were quantified with correlation coefficients of greater than 0.995. A high recovery (81.5–94.1%) and good reproducibility was obtained for five phenolics and three vitamins with the relative standard deviation, ranging from 1.2 to 3.5%. This method may be applied to the determination of both phenolics and water-soluble vitamins in cereal grain. The results may suggest that the extract of E. formosanus could be a good source of bioactive phytochemicals.

Colorimetric and Fluorescent Determination of Fluoride Using a Novel Naphthalene Diimide Boronic Acid Derivative

2016 ◽  
Vol 49 (14) ◽  
pp. 2301-2311 ◽  
Author(s):  
Luis Ernesto Solís-Delgado ◽  
Adrián Ochoa-Terán ◽  
Anatoly K. Yatsimirsky ◽  
Georgina Pina-Luis
Keyword(s):  
Acid Derivative ◽  
Boronic Acid ◽  
Naphthalene Diimide

Controlled Release of Metformin Hydrochloride I. In vitro Release from Physical Mixture Containing Xanthan Gum as Hydrophilic Rate Retarding Polymer

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza
Keyword(s):  
Controlled Release ◽  
Xanthan Gum ◽  
In Vitro Release ◽  
Correlation Coefficients ◽  
High Ratio ◽  
Water Soluble ◽  
Metformin Hydrochloride ◽  
Model Drug ◽  
Very High

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

Simultaneous Spectrophotometric Determination of Salbutamol by Coupling with Diazotized 4-Aminobenzoic acid

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Hind Hadi ◽  
Gufran Salim
Keyword(s):  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Dosage Forms ◽  
Water Soluble ◽  
Trace Determination ◽  
Aminobenzoic Acid ◽  
Optimum Conditions ◽  
Colored Product ◽  
Versus Concentration

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.

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