scholarly journals Paper-based standard addition assays

2014 ◽  
Vol 6 (5) ◽  
pp. 1296-1300 ◽  
Author(s):  
Cory A. Chaplan ◽  
Haydn T. Mitchell ◽  
Andres W. Martinez
Keyword(s):  
Digital Image ◽  
Microfluidic Devices ◽  
Standard Addition ◽  
Lighting Conditions

Standard addition assays conducted on paper-based microfluidic devices are introduced as an alternative to external standards for calibrating quantitative tests. To demonstrate this technique, a colorimetric, paper-based, standard addition assay was optimized for the determination of glucose concentrations in the range of 0 to 5 mM. Comparable results were obtained from the assay via digital image colorimetry under three different lighting conditions.

scholarly journals Application of Derivative, Derivative Ratio, and Multivariate Spectral Analysis and Thin-Layer Chomatography-Densitometry for Determination of a Ternary Mixture Containing Drotaverine Hydrochloride, Caffeine, and Paracetamol

2007 ◽  
Vol 90 (2) ◽  
pp. 391-404 ◽  
Author(s):  
Fadia H Metwally ◽  
Yasser S El-Saharty ◽  
Mohamed Refaat ◽  
Sonia Z El-Khateeb
Keyword(s):  
Thin Layer ◽  
Least Squares ◽  
Ternary Mixture ◽  
Principal Component Regression ◽  
Pharmaceutical Preparations ◽  
Principal Component ◽  
Standard Addition ◽  
Drotaverine Hydrochloride ◽  
Assay Precision

Abstract New selective, precise, and accurate methods are described for the determination of a ternary mixture containing drotaverine hydrochloride (I), caffeine (II), and paracetamol (III). The first method uses the first (D1) and third (D3) derivative spectrophotometry at 331 and 315 nm for the determination of (I) and (III), respectively, without interference from (II). The second method depends on the simultaneous use of the first derivative of the ratio spectra (DD1) with measurement at 312.4 nm for determination of (I) using the spectrum of 40 μg/mL (III) as a divisor or measurement at 286.4 and 304 nm after using the spectrum of 4 μg/mL (I) as a divisor for the determination of (II) and (III), respectively. In the third method, the predictive abilities of the classical least-squares, principal component regression, and partial least-squares were examined for the simultaneous determination of the ternary mixture. The last method depends on thin-layer chromatography-densitometry after separation of the mixture on silica gel plates using ethyl acetatechloroformmethanol (16 + 3 + 1, v/v/v) as the mobile phase. The spots were scanned at 281, 272, and 248 nm for the determination of (I), (II), and (III), respectively. Regression analysis showed good correlation in the selected ranges with excellent percentage recoveries. The chemical variables affecting the analytical performance of the methodology were studied and optimized. The methods showed no significant interferences from excipients. Intraday and interday assay precision and accuracy values were within regulatory limits. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of their pharmaceutical preparations. The validity of the proposed methods was further assessed by applying a standard addition technique. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.

scholarly journals Recent Advances in Microfluidic Devices for Contamination Detection and Quality Inspection of Milk

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 558
Author(s):  
Hwee-Yeong Ng ◽  
Wen-Chin Lee ◽  
Chia-Te Kung ◽  
Lung-Chih Li ◽  
Chien-Te Lee ◽  
...  
Keyword(s):  
Foodborne Pathogens ◽  
Human Life ◽  
Microfluidic Devices ◽  
Quality Inspection ◽  
Milk Samples ◽  
Sample Preconcentration ◽  
Sample Extraction ◽  
Microfluidic Analysis ◽  
Sample Separation

Milk is a necessity for human life. However, it is susceptible to contamination and adulteration. Microfluidic analysis devices have attracted significant attention for the high-throughput quality inspection and contaminant analysis of milk samples in recent years. This review describes the major proposals presented in the literature for the pretreatment, contaminant detection, and quality inspection of milk samples using microfluidic lab-on-a-chip and lab-on-paper platforms in the past five years. The review focuses on the sample separation, sample extraction, and sample preconcentration/amplification steps of the pretreatment process and the determination of aflatoxins, antibiotics, drugs, melamine, and foodborne pathogens in the detection process. Recent proposals for the general quality inspection of milk samples, including the viscosity and presence of adulteration, are also discussed. The review concludes with a brief perspective on the challenges facing the future development of microfluidic devices for the analysis of milk samples in the coming years.

scholarly journals Spectrophotometric Determination of Zidovudine in Pharmaceuticals Based on Charge-Transfer Complexation Involving N-Bromosuccinimide, Metol and Sulphanilic Acid as Reagents

2007 ◽  
Vol 4 (2) ◽  
pp. 173-179 ◽  
Author(s):  
K. Basavaiah ◽  
U. R. Anil Kumar
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Sulphanilic Acid ◽  
Bulk Drug ◽  
Student’S T ◽  
Charge Transfer Complexation

A simple spectrophotometric method is proposed for the determination of zidovudine(ZDV) in bulk drug and in pharmaceutical preparations. The method is based on the oxidation of ZDV by a known excess of oxidant N-bromosuccinimide (NBS), in buffer medium of pH 1.5, followed by the estimation of unreacted amount of oxidant with metol and sulphanilic acid. The reacted oxidant corresponds to the amount ZDV. The purple-red reaction product absorbs maximally at 530 nm and Beer’s law is obeyed over a range 5 to 75 μg mL-1. The apparent molar absorptivity is calculated to be 5.1×103L mol-1cm-1, and the corresponding Sandell sensitivity value is 0.052 μg cm-2. The limit of detection and quantification are found to be 0.90 and 2.72, respectively. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The method was successfully applied to the assay of ZDV in tablet/capsule preparations and the results were statistically compared with those of the reference method by applying the Student’s t-test and F-test. No interference was observed from the common tablet/capsule excipients. The accuracy of the method was further ascertained by performing recovery studies via standard-addition method.

Estimation of bodyweight from body measurements and determination of body measurements on Limousin cattle using digital image analysis

2016 ◽  
Vol 56 (12) ◽  
pp. 2060 ◽  
Author(s):  
Serkan Ozkaya ◽  
Wojciech Neja ◽  
Sylwia Krezel-Czopek ◽  
Adam Oler
Keyword(s):  
Image Analysis ◽  
Body Length ◽  
Digital Image ◽  
Digital Image Analysis ◽  
Digital Camera ◽  
Body Measurements ◽  
Analysis Software ◽  
Body Area ◽  
Image Analysis Software

The objective of this study was to predict bodyweight and estimate body measurements of Limousin cattle using digital image analysis (DIA). Body measurements including body length, wither height, chest depth, and hip height of cattle were determined both manually (by measurements stick) and by using DIA. Body area was determined by using DIA. The images of Limousin cattle were taken while cattle were standing in a squeeze chute by a digital camera and analysed by image analysis software to obtain body measurements of each animal. While comparing the actual and predicted body measurements, the accuracy was determined as 98% for wither height, 97% for hip height, 94% for chest depth and 90.6% for body length. Regression analysis between body area and bodyweight yielded an equation with R2 of 61.5%. The regression equation, which included all body traits, resulted in an R2 value of 88.7%. The results indicated that DIA can be used for accurate prediction of body measurements and bodyweight of Limousin cattle.

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