Accuracy Improvements in LPC Measurements for CMP Slurries

2009 ◽  
Vol 1157 ◽  
Author(s):  
Bruno Tolla ◽  
David Boldridge
Keyword(s):  
Analytical Method ◽  
Large Particle ◽  
Current Method ◽  
Particle Count ◽  
Accuracy And Precision

AbstractWe have examined the Large Particle Count (LPC) analytical method to see whether there are opportunities to improve both the accuracy and precision in hope of improving the utility of the LPC measurement. We have identified weaknesses in the current method that limit both its accuracy and its precision, and which can introduce count errors in excess of a factor of 10. We propose modifications to the current method which result in both accuracy and precision improvements. We recommend these improvements as absolutely necessary for any experiments designed to test the correlation between LPC and defectivity.

Analytical method for the determination of curcumin entrapped in polymeric micellar powder using HPLC

2021 ◽  
Vol 32 (4) ◽  
pp. 867-873
Author(s):  
Helmy Yusuf ◽  
Nina Wijiani ◽  
Rizka Arifa Rahmawati ◽  
Riesta Primaharinastiti ◽  
M. Agus Syamsur Rijal ◽  
...  
Keyword(s):  
Flow Rate ◽  
Analytical Method ◽  
Hplc Method ◽  
Array Detector ◽  
Good Resolution ◽  
Diode Array Detector ◽  
Accuracy And Precision ◽  
The Family ◽  
Effective Analysis

Abstract Objectives Curcumin belongs to the family of curcuminoids, natural polyphenolic compounds that possesses neuroprotective properties, anti inflammatory and anticancer. Its entrapment in the developed casein-based micellar powder (CMP) and poloxamer-based micellar powder (PMP) was to enhance the solubility and improve the bioavailability. Henceforth, the present study aimed to acquire an efficient analytical method for the curcumin analysis in polymeric micellar formulations. Methods A fast and specific HPLC method was developed for analyzing curcumin in two different micellar matrices using casein and poloxamer. The HPLC was equipped with a C18 column (250 × 4 mm, 5 µm) and diode array detector. A designated isocratic elution of curcumin was employed using mobile phase with a composition of water (1%, v/v acetic acid) and acetonitrile in a ratio of 50:50 v/v. The employed flow rate was 1.0 mL/min and the analyte was examined at 421 nm. Results An effective analysis in HPLC was successfully achieved by the predetermined HPLC condition. A good resolution of peaks at the employed flow rate was achieved. The linearity was excellent in two different range of concentrations, 2–20 and 10–50 μg/mL. The selectivity, accuracy and precision fulfilled the acceptable requirements. Conclusions The developed method was practically effective to qualitatively identified curcumin. In addition, the assay also effectively quantified the amount of curcumin in the polymeric entrapping matrices which demonstrates that it has great potential to be used in natural compound analysis.

scholarly journals A New Analytical Method for Spherical Thin Shells’ Axisymmetric Vibrations

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Mariame Nassit ◽  
Abderrahmane El Harif ◽  
Hassan Berbia ◽  
Mourad Taha Janan
Keyword(s):  
Analytical Method ◽  
Natural Frequencies ◽  
Equations Of Motion ◽  
Current Method ◽  
Free Edge ◽  
Free Vibrations ◽  
Thin Shells ◽  
Element Calculation ◽  
Spherical Shells ◽  
Clamped Edge

In order to improve the spherical thin shells’ vibrations analysis, we introduce a new analytical method. In this method, we take into consideration the terms of the inertial couples in the stress couples’ differential equations of motion. These inertial couples are omitted in the theories provided by Naghdi–Kalnins and Kunieda. The results show that the current method can solve the axisymmetric vibrations’ equations of elastic thin spherical shells. In this paper, we focus on verifying the current method, particularly for free vibrations with free edge and clamped edge boundary conditions. To check the validity and accuracy of the current analytical method, the natural frequencies determined by this method are compared with those available in the literature and those obtained by a finite element calculation.

Vibrations and Power Flows in a Coupled Beam System

2007 ◽  
Vol 129 (5) ◽  
pp. 616-622 ◽  
Author(s):  
Wen L. Li ◽  
Murilo W. Bonilha ◽  
Jie Xiao
Keyword(s):  
Boundary Conditions ◽  
Analytical Method ◽  
Power Flow ◽  
Practical Interest ◽  
Current Method ◽  
Beam System ◽  
The Subject ◽  
Coupled Beams ◽  
Elastically Restrained ◽  
Excellent Accuracy

Vibrations of and power flow between coupled beams have been the subject of many investigations, and various techniques have been developed over the years. However, most of the existing methods will require a certain level of modifications or adaptations to account for the variations in the coupling and∕or boundary conditions. In this study, a general analytical method is developed for predicting the vibrations of and power flow between two-coupled beams. The coupling between the beams is generically represented by two (translational and rotational) springs of arbitrary stiffnesses. Thus, many rigid and nonrigid connectors of practical interest can be directly taken into account. In addition, because the beams are elastically restrained at each end, the current method can be universally applied to different boundary conditions by simply varying the stiffnesses of the boundary springs. Numerical results are presented to show the excellent accuracy of the proposed approach.

Application of spatial analysis techniques to adjust for fertility trends and identify interplot competition in early stage sugarcane selection trials

2002 ◽  
Vol 53 (8) ◽  
pp. 911 ◽  
Author(s):  
J. K. Stringer ◽  
B. R. Cullis
Keyword(s):  
Spatial Analysis ◽  
Early Stage ◽  
Sugar Content ◽  
Current Method ◽  
Cane Yield ◽  
Field Variation ◽  
Breeding Programs ◽  
Fertility Trends ◽  
Accuracy And Precision ◽  
Modelling Approach

Most sugarcane breeding programs in Australia use large unreplicated trials to evaluate clones in the early stages of selection. Commercial varieties that are replicated provide a method of local control of soil fertility. Although such methods may be useful in detecting broad trends in the field, variation often occurs on a much smaller scale. Methods such as spatial analysis adjust a plot for variability by using information from immediate neighbours. These techniques are routinely used to analyse cereal data in Australia and have resulted in increased accuracy and precision in the estimates of variety effects. In this paper, spatial analyses in which the variability is decomposed into local, natural, and extraneous components are applied to early selection trials in sugarcane. Interplot competition in cane yield and trend in sugar content were substantial in many of the trials and there were often large differences in the selections between the spatial and current method used by the Bureau of Sugar Experiment Stations. A joint modelling approach for tonnes sugar per hectare in response to fertility trends and interplot competition is recommended.

scholarly journals Analytical Method Validation of Azadirachtin Extracted From Azadirachta Indica

2017 ◽  
Vol 2 (04) ◽  
pp. 99-106
Author(s):  
Syed Imran Ul Haq ◽  
Tribhuvan Singh ◽  
Shaik Mohammed Salman ◽  
Afifa Namreen ◽  
Anas Rasheed
Keyword(s):  
Regression Analysis ◽  
Statistical Analysis ◽  
Azadirachta Indica ◽  
Spectrophotometric Method ◽  
Drug Concentration ◽  
Analytical Method ◽  
Distilled Water ◽  
Analytical Method Validation ◽  
Accuracy And Precision

A simple UV spectrophotometric method for the determination of Azadirachtin is developed exhibiting maximum absorbance using distilled water at 542nm.The present study is based on the detection of sample drug concentration using dichloro methane as diluent. All the conditions required were optimized. Statistical analysis was carried out and results of which were satisfactory. The optical characteristics such as absorption maxima, regression analysis and correlation coefficient are obtained. Recovery studies were close to 100% that indicate the accuracy and precision of proposed method and the non-interference of the formulation excipients. All the valid parameters are summarized.

scholarly journals ANALYTICAL METHOD OPTIMIZATION AND VALIDATION OF GLIBENCLAMIDE AND METFORMIN HYDROCHLORIDE IN DIABETIC HERBS PRODUCT BY THIN-LAYER CHROMATOGRAPHY-DENSITOMETRY

2020 ◽  
pp. 83-87
Author(s):  
BAITHA PALANGGATAN MAGGADANI ◽  
NOVIANI SUGIANTO ◽  
HAYUN
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Analytical Method ◽  
Mobile Phase ◽  
Glacial Acetic Acid ◽  
Correlation Coefficients ◽  
Metformin Hydrochloride ◽  
Accuracy And Precision ◽  
Method Optimization ◽  
Layer Chromatography

Objective: This study aimed to develop and validate an analytical method using thin-layer chromatography (TLC)-densitometry for detecting thepresence of glibenclamide and metformin hydrochloride in herbal diabetic products.Methods: The jamu samples were extracted using methanol, followed by analysis using TLC-densitometry with methanol-aquades-glacial acetic acid(9:1:0.25) as the mobile phase at a wavelength of 237 nm.Results: From the validation results, the correlation coefficients for glibenclamide and metformin hydrochloride were determined to be 0.9998and 0.9981, respectively. The limits of detection and quantitation for glibenclamide were 49.97 μg/mL and 66.55 μg/mL, respectively, while thoseof metformin hydrochloride were 74.75 μg/mL and 249.25 μg/mL, respectively. The method developed in this study met the criteria of selectivity,accuracy, and precision. From seven jamu samples tested, four tested positive for glibenclamide, with sample 1=4.9522%, sample 2=4.1495%, sample3=4.2578%, and sample 4=4.9412%.Conclusion: None of the jamu samples contained metformin hydrochloride.

scholarly journals Simultaneous Determination of 5 Flavonoids and 7 Saponins for Quality Control of Traditional Chinese Medicine Preparation Xinnaoshutong Capsule Using HPLC-VWD-ELSD

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Jin Li ◽  
Yang Bai ◽  
Peng Zhang ◽  
Jun He ◽  
Jun Cao ◽  
...  
Keyword(s):  
Quality Control ◽  
Analytical Method ◽  
Mobile Phase ◽  
Gradient Elution ◽  
Tribulus Terrestris ◽  
Ripe Fruit ◽  
Accuracy And Precision ◽  
Marker Compounds ◽  
Traditional Chinese Medicine Preparation

Xinnaoshutong capsule (XC) is a traditional Chinese prescription derived from the ripe fruit of Tribulus terrestris L. (TT). Although XC has long been considered as an important herbal medicine, no analytical method of marker compounds for quality assessment is registered in the Chinese Pharmacopoeia. A simple analytical method of twelve marker components was developed and validated by HPLC-VWD-ELSD method. Chromatographic separation by HPLC was carried out on a Hedera ODS 2 column (4.6 × 250 mm, 5 μm) by gradient elution with acetonitrile-water (0.1% formic acid) as the mobile phase. Various extraction conditions were optimized to achieve twelve marker compounds with faster extraction and higher recovery. The analytical condition was then validated in terms of the linearity, accuracy and precision, repeatability, and stability. The twelve markers were successfully quantified in 30 batches of commercial samples. The developed HPLC-VWD-ELSD could be used as a rapid and reliable way in the assessment and quality control of XC and TT.

Screening Study on Frictional Force Analysis in Relation to Silica Abrasive and Slurry Properties

2007 ◽  
Vol 991 ◽  
Author(s):  
Yun Zhuang ◽  
Yasa Adi Sampurno ◽  
Fransisca Sudargho ◽  
Geoff Steward ◽  
Herbert Barthel ◽  
...  
Keyword(s):  
Particle Size ◽  
Frictional Force ◽  
Fumed Silica ◽  
Large Particle ◽  
Removal Rate ◽  
Silica Powder ◽  
Particle Count ◽  
Mean Particle Size ◽  
Large Size ◽  
Slurry Viscosity

ABSTRACTIn this study, different amounts of standard fumed silica and fumed silica contaminated by coarse particles was added as powder to a standard copper CMP slurry to investigate their effects on large particle count, mean particle size, slurry viscosity, frictional force during wafer polishing, and copper removal rate. Standard silica powder consisted of the same particles used in the standard slurry while contaminated silica powder consisted of the same particles used in the standard slurry and additional large size particles. Large particle count analysis indicated that slurry dispersion itself generated large size particles in the slurries. The addition of 0.3% and 1% contaminated silica to the standard slurry caused significant increases in large particle count, and the mean particle size increased with the amount of contaminated silica added to the standard slurry. The slurry viscosity generally increased with the amount of standard and contaminated silica added to the standard slurry under the shear rate of 100 s−1. The standard slurry and slurries added with 0.3% and 1% contaminated silica were used to polish 200-mm blanket copper wafers on the APD-500 polisher that has the unique ability to measure frictional force in real time during polishing. The coefficient of friction increased with the amount of contaminated silica added to the standard slurry. In general, the removal rates for the slurry added with 1% contaminated silica were higher than the standard slurry and slurry added with 0.3% contaminated silica.

Analysis of Large Particle Count in Fumed Silica Slurries and Its Correlation with Scratch Defects Generated by CMP

2006 ◽  
Vol 153 (5) ◽  
pp. G453 ◽  
Author(s):  
Edward E. Remsen ◽  
Sriram Anjur ◽  
David Boldridge ◽  
Mungai Kamiti ◽  
Shoutian Li ◽  
...  
Keyword(s):  
Fumed Silica ◽  
Large Particle ◽  
Particle Count

scholarly journals Determination of Parabens, Bisphenol A and Its Analogs, Triclosan, and Benzophenone-3 Levels in Human Urine by Isotope-Dilution-UPLC-MS/MS Method Followed by Supported Liquid Extraction

Toxics ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Hsin-Chang Chen ◽  
Jung-Wei Chang ◽  
Yi-Chen Sun ◽  
Wan-Ting Chang ◽  
Po-Chin Huang
Keyword(s):  
Isotope Dilution ◽  
Human Urine ◽  
Analytical Method ◽  
Antibacterial Agents ◽  
Human Biomonitoring ◽  
Liquid Extraction ◽  
Urine Samples ◽  
Accuracy And Precision ◽  
Liquid Chromatography Tandem Mass ◽  
Artificial Urine

The development of a rapid analytical approach for determining levels of antibacterial agents, plasticizers, and ultraviolet filters in biosamples is crucial for individual exposure assessment. We developed an analytical method to determine the levels of four parabens—bisphenols A (BPA) and its analogs, triclosan (TCS), triclocarban, and benzophenone-3 (BP-3)—in human urine. We further measured the levels of these chemicals in children and adolescents. We used a supported liquid extraction (SLE) technique coupled with an isotope-dilution ultraperformance liquid chromatography-tandem mass spectrometry (ID-UPLC-MS/MS) method to assess the detection performance for these chemicals. Forty-one urine samples from 13 children and 28 adolescents were assessed to demonstrate the capability and feasibility of our method. An acceptable recovery (75.6–102.4%) and matrix effect (precision < 14.2%) in the three-level spiked artificial urine samples were achieved, and good performance of the validated ID-UPLC-MS/MS method regarding linearity, limits of detection, and quantitation was achieved. The within-run and between-run accuracy and precision also demonstrated the sensitivity and stability of this analytical method, applied after SLE. We concluded that the ID-UPLC-MS/MS method with SLE pretreatment is a valuable analytical method for the investigation of urinary antibacterial agents, plasticizers, and ultraviolet filters in humans, useful for human biomonitoring.

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