Novel Analytical Approach for the Determination of Zirconium and Yttrium in Ysz Powders

2012 ◽  
Vol 51 (4) ◽  
pp. 428-435
Author(s):  
A. Zarkov ◽  
A. Zalga ◽  
S. Tautkus ◽  
A. Kareiva
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Analytical Approach ◽  
Analytical Procedure ◽  
Sol Gel ◽  
Calibration Graph ◽  
Gel Method ◽  
Spectrophotometric Methods ◽  
Relative Standard

Two simple and sensitive spectrophotometric methods for the determination of zirconium and yttrium in YSZ specimens have been suggested in this study. The calibration graph for zirconium and yttrium was linear in the range of 0.08-0.4 and 0.1-0.6 μg/mL, respectively. The proposed analytical procedure was applied for the determination of zirconium and yttrium in the YSZ samples synthesized by aqueous sol-gel method. The relative standard deviation (RSD) for zirconium was in the range from 0.6 to 4.5%, for yttrium it was from 0.6 to 3.6%. The achieved results demonstrated that the suggested procedure could be successfully applied for the analysis of YSZ powders with satisfactory accuracy.

Cloud Point Extraction-Fluorimetric Combined Methodology for the Determination of Magnolol

2013 ◽  
Vol 699 ◽  
pp. 34-39
Author(s):  
Li Liu ◽  
Xia Shi Zhu
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Cloud Point ◽  
Relative Standard Deviation ◽  
Cloud Point Extraction ◽  
Calibration Graph ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Triton X

A new Triton X-114 cloud point extraction combined with fluorometry method for analysis of magnolol in drug samples was developed. Under the optimum conditions, the calibration graph was linear in the range of 2.0-150.0ng/mL of magnolol in the initial solution with r = 0.9998. Detection limit (DL) was 0.03ng/mL (S/N=3) and the relative standard deviation (RSD) for 20.0ng/mL of magnolol was 2.79%(n=11). The method was successfully applied for the determination of magnolol in drug samples with satisfactory results.

Determination of diltiazem based on the reduction of Cu(II)–BCA complexes in micellar medium

2010 ◽  
Vol 88 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Larissa Zuppardo Lacerda Sabino ◽  
Daniele Cestari Marino ◽  
Horacio Dorigan Moya
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Confidence Level ◽  
Limit Of Detection ◽  
Calibration Graph ◽  
Micellar Medium ◽  
Solution Ph ◽  
Simple Method ◽  
Relative Standard

A simple method was developed for determining microquantities of diltiazem, based on the reduction of copper(II) in buffered solution (pH 7.0) and the use of a micellar medium containing 4,4′-dicarboxy-2,2′-biquinoline acid. The copper(I) produced reacts with 4,4′-dicarboxy-2,2′-biquinoline acid and the complexes formed are spectrophotometrically measured at 558 nm. A typical calibration graph shows good linearity (r = 0.993) from 20 to 100 μg mL–1 of diltiazem. The limit of detection and relative standard deviation were calculated as 12 μg mL–1 (99% confidence level) and 3.5% (40 μg mL–1; n = 6), respectively, with a mean recovery value of 96.5% found in pharmaceutical dosages. A straightforward and effective way to recycle the reagents is addressed. The hazardous aspects of the Cu(I)–BCA reaction are presented as well.

Voltammetric Determination of Metals in Copper Alloys at Trace and Ultratrace Concentrations

2003 ◽  
Vol 68 (8) ◽  
pp. 1437-1448 ◽  
Author(s):  
Clinio Locatelli ◽  
Giancarlo Torsi
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Relative Error ◽  
Analytical Procedure ◽  
Copper Alloys ◽  
Voltammetric Determination ◽  
Standard Reference Materials ◽  
Relative Standard ◽  
Precision And Accuracy

The present work describes the analytical procedures for the voltammetric determination of Cu, Pb, Cd, Zn, Fe, Mn, Co, Ni, Sn, Sb and Bi in copper alloys. The possibility of determining simultaneously metal concentrations in the case of interference of the voltammetric signals due to the peak overlapping is also highlighted and discussed. The analytical procedure was verified by the analysis of the standard reference materials: commercial bronze A NIST-SRM 1115, gunmetal BCS-CRM 207/2, high tensile brass BCS-CRM 390. Precision and accuracy, expressed as relative standard deviation and relative error, respectively, were in all cases lower than 6%. The limits of detection for each element were also reported.

scholarly journals Spectrophotometric Determination of Lamivudine in Pure and Tablet Forms

2012 ◽  
Vol 9 (2) ◽  
pp. 569-575 ◽  
Author(s):  
A. Biksham Babu ◽  
G. Ramu ◽  
Ch. Muralikrishna ◽  
S. Brahma Reddy ◽  
C. Rambabu
Keyword(s):  
Standard Deviation ◽  
Correlation Coefficient ◽  
Relative Standard Deviation ◽  
Diazonium Salt ◽  
Salt Formation ◽  
Spectrophotometric Methods ◽  
Confidence Levels ◽  
Relative Standard ◽  
Colored Product

Two visible spectrophotometric methods have been developed for the determination of Lamivudine(LMV) in pure and tablet forms. Method-A is based on oxidation of 3-methyl-2-benzathiazolinone hydrazone (MBTH) in the presence of iodoso benzene diacetate (IBDA) to form electrophilic intermediate which is an active coupling species that reacts with the coupler (LMV) by electrophillic attack on the most nucleophilic site on cyclic ring of the coupler. Method-B depends on diazonium salt formation and consequent reaction with resorcinol producing colored product. The absorbances are measured at 590 nm and 540 nm for Method-A and Method-B respectively. Beer's law is obeyed in the concentration range of 10.0-60.0 μg/mL for both the methods. The correlation coefficient which is very close to unity indicates that there is good correlation between concentration and absorbance. LOD, LOQ, confidence levels and relative standard deviation are calculated for the developed methods. The developed methods were successfully applied to tablet forms.

scholarly journals Determination of formaldehyde in production solutions using the piezoelectric sensors

2021 ◽  
Vol 25 (2) ◽  
pp. 140-145
Author(s):  
A. A. Merenkova ◽  
◽  
K. V. Zhuzhukin ◽  
A. N. Zyablov ◽  
L. I. Belchinskaya ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Piezoelectric Sensor ◽  
Calibration Graph ◽  
Piezoelectric Sensors ◽  
Coefficient Of Determination ◽  
Relative Standard ◽  
Production Solutions ◽  
Industrial Solutions

In the current work, piezoelectric sensors based on a molecular imprinted polymer (MIP) were obtained for determining the formaldehyde in the industrial solutions of a woodworking plant. The synthesis was carried out directly on the surface of the piezoelectric sensor. In the process of the two-stage thermoimidization of the obtained prepolymerization mixture, a molecular imprinted polyimide of formaldehyde was formed. For the analysis of the supra-resin part of the effluent of the Grafskaya kuhnya LLC (Voronezh) woodworking enterprise, which was obtained by the dry distillation of wood, the method of a calibration graph having a linear relationship was used; the coefficient of determination R2 = 0.97. The detection limit of the piezosensor was 0.6 ∙ 10–4 mol / dm3, the range of determined concentrations was 1.0 – 10–4 mol / dm3. The comparison of piezoelectric sensors based on the polymer without imprints and based on the polymer with imprints of formaldehyde showed high selectivity of the latter for the target molecule. The calculated imprinting factor was 28.3, the coefficient of selectivity with respect to phenol was 0.05, which indicated the selectivity of the modified sensor to formaldehyde. The verification of the correctness of the determination of formaldehyde in the model and production solutions was carried out using the "added-found" method. It was found that the MIP-based sensor was sensitive only to formaldehyde, the relative standard deviation did not exceed 2.0%. In order to assess the effect of the object matrix (formaldehyde) on the value of the resonant frequency, the standard addition method was used. It was determined that the matrix did not affect the value of the analytical signal, the relative standard deviation was 2.8%. For the re-analysis, the piezoelectric sensor was exposed to the regeneration in the oven at 50 ⁰С. The proposed method for determining the concentration of the formaldehyde using the MIP-sensor allowed controlling the content of the toxicant in the industrial solutions.

An Automated Procedure for the Determination of Ammonia in Tobacco

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Distillation Method ◽  
Relative Standard ◽  
Tobacco Sample ◽  
Automated Determination

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate

scholarly journals Indirect and Direct Determination of the Casein Content of Milk by Kjeldahl Nitrogen Analysis: Collaborative Study

1998 ◽  
Vol 81 (4) ◽  
pp. 763-774 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming
Keyword(s):  
Standard Deviation ◽  
Nitrogen Content ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Direct Determination ◽  
Raw Milk ◽  
Method Performance ◽  
Relative Standard ◽  
Milk Casein

Abstract The classic method for determination of milk casein is based on precipitation of casein at pH 4.6. Precipitated milk casein is removed by filtration and the nitrogen content of either the precipitate (direct casein method) or filtrate (noncasein nitrogen; NCN) is determined by Kjeldahl analysis. For the indirect casein method, milk total nitrogen (TN; Method 991.20) is also determined and casein is calculated as TN minus NCN. Ten laboratories tested 9 pairs of blind duplicate raw milk materials with a casein range of 2.42- 3.05℅ by both the direct and indirect casein methods. Statistical performance expressed in protein equivalents (nitrogen ⨯ 6.38) with invalid and outlier data removed was as follows: NCN method (wt%), mean = 0.762, sr = 0.010, SR = 0.016, repeatability relative standard deviation (RSDr) = 1.287℅, reproducibility relative standard deviation (RSDR) = 2.146%; indirect casein method (wt℅), mean = 2.585, repeatability = 0.015, reproducibility = 0.022, RSDr = 0.560℅, RSDR = 0.841; direct casein method (wt℅), mean = 2.575, sr = 0.015, sR = 0.025, RSDr = 0.597℅, RSDR = 0.988℅. Method performance was acceptable and comparable to similar Kjeldahl methods for determining nitrogen content of milk (Methods 991.20, 991.21,991.22, 991.23). The direct casein, indirect casein, and noncasein nitrogen methods have been adopted by AOAC INTERNATIONAL.

Determination of Nitrate in Water by HPLC

2013 ◽  
Vol 448-453 ◽  
pp. 406-408
Author(s):  
Jing Liu ◽  
Xiao Na Ji ◽  
Qing Kai Ren ◽  
Sheng Shu Ai ◽  
Li Jun Wan ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Recovery Rate ◽  
High Performance ◽  
Separation Efficiency ◽  
Fast Analysis ◽  
Relative Standard

We established a method fordetermination of nitrate in water by High Performance Liquid Chromatography(HPLC). The sample was analysed by HPLC-ADA and was quantitated by externalstandard method after being simply processed. This methd has the advantages ofhigh separation efficiency and fast analysis. The experiment result showed thatthe linearly dependent coefficient was0.994, the recovery rate was between 98.7%～105.7%,the relative standard deviation（RSD）wasless than 2.1 %, and the lowest detectable limit is 0.01ng (S/N=1.6).

scholarly journals Determination of 1,3-Dichloropropanol in Soy Sauce and Related Products by Headspace Gas Chromatography with Mass Spectrometric Detection: Interlaboratory Study

2005 ◽  
Vol 88 (5) ◽  
pp. 1404-1412 ◽  
Author(s):  
Sarah Hasnip ◽  
Colin Crews ◽  
Nicholas Potter ◽  
Paul Brereton ◽  
Henri Diserens ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Soy Sauce ◽  
Headspace Gas Chromatography ◽  
Relative Standard ◽  
Headspace Gas

Abstract An interlaboratory study was performed to evaluate the effectiveness of a headspace gas chromatography (GC) method for the determination of 1,3-dichloro-propan-2-ol (1,3-DCP) in soy sauce and related products at levels above 5 ng/g. The test portion is mixed with an internal standard (d5-1,3-DCP) and ammonium sulfate in a sealed headspace vial. After achieving equilibrium, the headspace is sampled either by gas-tight syringe or solid-phase microextraction (SPME) and analyzed by GC with mass spectrometric detection. 1,3-DCP is detected in the selected-ion mode (monitoring m/z 79 and 81 for 1,3-DCP and m/z 82 for the deuterated internal standard) and quantified by measurement against standards. Test materials comprising soy, dark soy, mushroom soy, and teriyaki sauces, both spiked and naturally contaminated, were sent to 9 laboratories in Europe, Japan, and the United States; of these, 5 used SPME and 4 used syringe headspace analysis. Test portions were spiked at 5.0, 10.0, 20.0, 100.0, and 500.0 ng/g. The average recovery for spiked blank samples was 108% (ranging from 96–130%). Based on results for spiked samples (blind pairs at 5, 10, 20, 100, and 500 ng/g) as well as a naturally contaminated sample (split-level pair at 27 and 29 ng/g), the relative standard deviation for repeatability (RSDr) ranged from 2.9–23.2%. The relative standard deviation for reproducibility (RSDR) ranged from 20.9–35.3%, and HorRat values of between 1.0 and 1.6 were obtained.

scholarly journals Development and validation of spectrophotometric method for phenylephrine hydrochloride estimation in nasal drops formulations

2008 ◽  
Vol 27 (2) ◽  
pp. 149 ◽  
Author(s):  
Ivana Savić ◽  
Goran Nikolić ◽  
Vladimir Banković
Keyword(s):  
Standard Deviation ◽  
Sodium Hydroxide ◽  
Relative Standard Deviation ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Phenylephrine Hydrochloride ◽  
Relative Standard ◽  
Development And Validation

Simple, accurate and reproducible UV-spectrophotometric method was developed and validated for the estimation of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. Phenylephrine hydrochloride was estimated at 291 nm in 1 mol⋅dm-3 sodium hydroxide (pH 13.5). Beer’s law was obeyed in the concentration range of 10–100 μg⋅cm−3 (r2 = 0.9990) in the sodium hydroxide medium. The apparent molar absorptivity was found to be 1.63×103 dm3⋅mol−1⋅cm−1. The method was tested and validated for various parameters according to the ICH (International Conference on Harmonization) guidelines. The detection and quantitation limits were found to be 0.892 and 2.969 μg⋅cm−3, respectively. The proposed method was successfully applied for the determination of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation < 1 %), while being simple, cheap and less time consuming, and hence can be suitably applied for the estimation of phenylephrine hydrochloride in different dosage forms.

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