10.55 A modified second derivative method to correct for the system effect in the determination of cardiac wall thickness: phantom experiment

2001 ◽  
Vol 8 (1) ◽  
pp. S73-S73
Author(s):  
N BALLANI ◽  
N SPYROU
Keyword(s):  
Wall Thickness ◽  
Second Derivative ◽  
Phantom Experiment ◽  
System Effect ◽  
Cardiac Wall ◽  
Derivative Method ◽  
Second Derivative Method

Different Spectrophotometric and Chromatographic Methods for Determination of Mepivacaine and Its Toxic Impurity

2017 ◽  
Vol 100 (5) ◽  
pp. 1392-1399 ◽  
Author(s):  
Nada S Abdelwahab ◽  
Nehal F Fared ◽  
Mohamed Elagawany ◽  
Esraa H Abdelmomen
Keyword(s):  
Particle Size ◽  
Stationary Phase ◽  
Second Derivative ◽  
Spectrophotometric Measurement ◽  
Spectrophotometric Methods ◽  
Derivative Method ◽  
Tlc Plates ◽  
Second Derivative Method ◽  
Developing System

Abstract Stability-indicating spectrophotometric, TLC-densitometric, and ultra-performance LC (UPLC) methods were developed for the determination of mepivacaine HCl (MEP) in the presence of its toxic impurity, 2,6-dimethylanaline (DMA). Different spectrophotometric methods were developed for the determination of MEP and DMA. In a dual-wavelength method combined with direct spectrophotometric measurement, the absorbancedifference between 221.4 and 240 nm was used for MEPmeasurements, whereas the absorbance at 283 nm was used for measuring DMA in the binary mixture. In the second-derivative method, amplitudes at 272.2 and 232.6 nm were recorded and used for the determination of MEP and DMA, respectively. The developed TLC-densitometric method depended on chromatographic separation using silica gel 60 F254 TLC plates as a stationary phase and methanol–water–acetic acid (9 + 1 + 0.1, v/v/v) as a developing system, with UV scanning at 230 nm. The developed UPLC method depended on separation using a C18 column (250 × 4.6 mm id, 5 μm particle size) as a stationary phase and acetonitrile–water (40 + 60, v/v; pH 4 with phosphoric acid) as a mobilephase at a flow rate of 0.4 mL/min, with UV detection at 215 nm. The chromatographic run time was approximately 1 min. The proposed methods were validated with respect to International Conference on Harmonization guidelines regarding precision, accuracy, ruggedness, robustness, and specificity.

scholarly journals VALIDATED SPECTROPHOTOMETRIC METHODS FOR THE ESTIMATION OF CINNARIZINE IN BINARY MIXTURE WITH PARACETAMOL IN BULK AND TABLETS

2021 ◽  
pp. 161-166
Author(s):  
AHMED M AL-GHANI ◽  
ANES AM THABET
Keyword(s):  
Quality Control ◽  
Second Derivative ◽  
Derivative Spectrum ◽  
Zero Crossing ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
Derivative Method ◽  
Analytical Tools ◽  
Second Derivative Method

Objectives: The aim of this work was to develop and validate new, simple, accurate, and selective spectrophotometric methods (derivative and derivative ratio spectrophotometric methods) for the determination of these drugs. These methods can be used as analytical tools in routine examination in quality control laboratories. Methods: The first method was derivative method in which the first derivative method (1D) for determination of PCM and the second derivative method (2D) for determination of CIN. The second method was the first derivative ratio spectrophotometric method (1DD) for determination of CIN and PCM. Results: In first method, the first derivative spectrum (1D) of PCM where PCM was determined by measuring the amplitude of the valley at 235 nm while CIN showed zero crossing spectrum, and the second derivative spectrum (2D) of CIN where CIN was determined by measuring the amplitude of the peak at 287.5 nm while PCM showed a zero value. In the second method, the first derivative ratio spectrophotometry (1DD) for CIN and PCM determination, where the amplitude at 290 and 291 nm, was selected for the determination of CIN and PCM, respectively. Conclusions: The developed methods were applied for the determination of the cited drugs in tablets containing binary drug mixture. The methods are simple and precise and can be used for routine analysis of the labeled drugs in combined dosage forms in quality control laboratories.

scholarly journals DERIVATIVE SPECTROPHOTOMETRY FOR NO3- DETERMINATION IN SANITARY SEWAGES

2020 ◽  
Vol 28 ◽  
pp. 579-583
Author(s):  
Tayane Cristiele Rodrigues Mesquita ◽  
Pamela Lais Cabral Silva ◽  
Lucas Rafael Lommez Vaz ◽  
Alisson Carraro Borges
Keyword(s):  
Organic Matter ◽  
Spectrophotometric Method ◽  
Second Derivative ◽  
Whitney Test ◽  
Satisfactory Performance ◽  
Significant Difference ◽  
Derivative Method ◽  
The Difference ◽  
Second Derivative Method

The objective of this study was to observe the feasibility of using the UV spectrophotometric method of the second derivative in the determination of nitrogen in the form of nitrate in sanitary sewers, since this method is indicated for water with low content of organic matter. Therefore, the results obtained in that method were compared with the salicylate methodology. The Mann-Whitney test showed a significant difference (? = 5%) between the results obtained in both methods. However, when compared, the difference between them was less than 0.25 mg L-1 in half of the observations. Despite this significant difference, the use of the second derivative method for sanitary sewage samples showed satisfactory performance.

Usefulness of a Curve Fitting Method in the Analysis of Overlapping Overtones and Combinations of CH Stretching Modes

2002 ◽  
Vol 10 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Yukiteru Katsumoto ◽  
Daisuke Adachi ◽  
Harumi Sato ◽  
Yukihiro Ozaki
Keyword(s):  
Curve Fitting ◽  
Second Derivative ◽  
Downward Shift ◽  
Fitting Method ◽  
Derivative Method ◽  
Structural Differences ◽  
Alcohol Mixtures ◽  
Curve Fitting Method ◽  
Second Derivative Method ◽  
Water Alcohol

This paper reports the usefulness of a curve fitting method in the analysis of NIR spectra. NIR spectra in the 7500–5500 cm−1 (1333–1818 nm) region were measured for water–methanol, water–ethanol and water–1-propanol mixtures with alcohol concentrations of 0–100 wt% at 25°C. The 6000–5600 cm−1 (1667–1786 nm) region, where the overtones and combinations of CH3 and CH2 stretching modes are expected to appear, shows significant band shifts with the increase in the alcohol content. To analyse the concentration-dependent spectral changes, a curve fitting method was utilised, and the results were compared with those obtained previously by a second derivative method. It was found that the first overtones of CH3 asymmetric and symmetric stretching modes of alcohols show a downward shift by about 15–30 cm−1 with the increase in the concentration of alcohols. The shifts are much larger for water–methanol mixtures than for water–ethanol and water–1-propanol mixtures. The first overtones and combinations of CH2 stretching modes of ethanol and 1-propanol also show a small downward shift. These shifts support our previous conclusion that there is an intermolecular “CH⃛O” interaction between the methyl group and water in the water–alcohol mixtures. The curve fitting method provided more feasible results for the band shifts than the second derivative method. It was revealed from the curve fitting method that the first overtone of the CH3 asymmetric stretching mode of water–methanol, water–ethanol and water–1-propanol mixtures shows different concentration-dependent plots. The first overtone of CH3 asymmetric stretching mode of water–methanol mixtures shifts more rapidly in the high methanol concentration range while that of water–1-propanol concentration shifts more markedly in the low 1-propanol concentration range. That of water–ethanol mixtures shows an intermediate trend. Based upon these differences structural differences among the three kinds of water–alcohol mixtures are discussed.

Second-Derivative UV Spectrometric Microdetermination of Dithiocarbamate Residues as Methyl Xanthate

1995 ◽  
Vol 78 (2) ◽  
pp. 458-462 ◽  
Author(s):  
Wolfgang Schwack ◽  
Steven Nyanzi
Keyword(s):  
Classical Method ◽  
Residue Analysis ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Second Derivative ◽  
Acid Decomposition ◽  
Negative Peak ◽  
Fungicide Residues ◽  
Derivative Method ◽  
Second Derivative Method

Abstract The microdetermination of dithiocarbamate fungicide residues as methyl xanthate using second-derivative UV spectrometry is described. The residue analysis is based on a hot-acid decomposition, scrubbing the evolved CS2 with lead acetate and concentrated H2SO4, and absorbing the CS2 in methanolic KOH. The absorbance of the xanthate system (conventional method) and the height of the negative peak at 302 nm (second-derivative method) are used to quantitate the CS2. The molar absorptivity of the xanthate system within the range of 0.3–2.4 μg CS2/mL where Beer’s law is obeyed, was 1.70 × 104 L mol-1 cm-1. The derivative procedure was more selective and sensitive to CS2 than the classical method. The calibration graph of the derivative procedure was rectilinear from 0.1–1.1 μg/mL of CS2. The coefficient of variation for the determination (n = 10) of a 0.28 (μg/mL standard of CS2 was 2.6%. The detection limit for CS2 was 0.08 μg/mL. The second-derivative procedure was applied to the residue analysis of thiram on tomatoes.

Sign in / Sign up

Export Citation Format

Share Document