Determination of Lead in Soil

1972 ◽  
Vol 26 (4) ◽  
pp. 456-460 ◽  
Author(s):  
J. L. Seeley ◽  
D. Dick ◽  
J. H. Arvik ◽  
R. L. Zimdahl ◽  
R. K. Skogerboe
Keyword(s):  
Atomic Absorption ◽  
Concentration Ratio ◽  
Lead Concentration ◽  
Analytical Determination ◽  
Precision Data ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision

The analytical determination of lead in soil is discussed with particular reference to emission spectrographic and atomic absorption spectrophotometric methods. The problems associated with the two techniques are discussed, and accuracy and precision data are presented. Data indicating that the titanium-to-lead concentration ratio can be used to differentiate between lead-contaminated and noncontaminated soils are presented.

scholarly journals Uv Spectrophotometric Methods for Determination of Sofosbuvir in Pure Form and Pharmaceutical Dosage Forms in Presence of Its Alkaline Degradate

2020 ◽  
pp. 12-25
Author(s):  
Zeinab Adel Nasr ◽  
Noha S. Said ◽  
Sawsan A. Abdel-Razeq
Keyword(s):  
Good Accuracy ◽  
Dosage Forms ◽  
Difference Spectra ◽  
Pharmaceutical Dosage Forms ◽  
Spectrophotometric Methods ◽  
Good Linearity ◽  
Ratio Difference ◽  
Accuracy And Precision ◽  
Tablet Dosage

Aims: Two spectrophotometric methods were developed and validated for the determination of sofosbuvir in presence of its alkaline degradate. Study Design: Ratio difference and ratio derivative methods were assisted for determination of sofosbuvir in presence of its alkaline degradate, laboratory-prepared mixtures and in tablet dosage forms. Place and Duration of Study: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy (Girls), Al - Azhar University, between December 2019 and January 2020. Methodology: Two analytical methods were achieved and validated for the quantitative determination of Sofosbuvir in presence of its alkaline degradate. The first method was ratio difference (RD) method, where the UV absorption spectra of different concentrations of sofosbuvir were divided by the spectrum of a certain concentration (15 µg mL-1) as a devisor of its alkaline degradate to get the ratio difference spectra. Afterwards, the peak amplitudes difference between 253.7 and 243.5 nm were measured. The second method was the ratio derivative (1DR) method, where the first derivative of the ratio spectra (1DR) was obtained and its amplitude was measured at 247 and 268 nm. Good linearity was obtained over the concentration range of 3-15 µg mL-1 for the proposed methods. The proposed procedures were adopted for the selective determination of intact Sofosbuvir in presence of up to 80% of its degradation product. Sofosbuvir was exposed to different conditions as alkaline, acidic and oxidative degradation. Results: The proposed methods were developed and validated with good linearity range of 3-15 µg mL-1 for both methods, and also with good accuracy and precision. And the obtained results were statistically compared to those obtained by the reported method. Conclusion: Sofosbuvir was successfully determined by the proposed ratio difference and ratio derivative methods in bulk powder, laboratory prepared mixtures and tablet dosage form with good accuracy and precision. The methods were validated according to ICH guidelines. The results obtained were compared with those of the reported method and were found to be in good agreement.

scholarly journals Extractive Spectrophotometric Methods for Determination of Zolmitriptan in Tablets

2007 ◽  
Vol 90 (5) ◽  
pp. 1237-1241 ◽  
Author(s):  
Zeynep Aydogmus ◽  
Ipek Inanli
Keyword(s):  
High Performance ◽  
Correlation Coefficients ◽  
Bromothymol Blue ◽  
Chromatography Method ◽  
Statistical Comparison ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Liquid Chromatography Method ◽  
Comparison Of The Results

Abstract Two simple and sensitive extractive spectrophotometric methods have been developed for determination of zolmitriptan (ZTP) in tablets. These methods are based on the formation of yellow ion-pair complexes between ZTP and tropaeolin OO (TPOO) and bromothymol blue (BTB) in citratephosphate buffer of pH 4.0 and 6.0, respectively. The formed complexes were extracted with dichloromethane and measured at 411.5 and 410 nm for TPOO and BTB, respectively. The best conditions of the reactions were studied and optimized. Beer's law was obeyed in the concentration ranges of 220 and 1.517 g/mL with molar absorptivities of 1.42 104 and 1.60 104 L/mol/cm for the TPOO and BTB methods, respectively. Correlation coefficients were 0.9998 and 0.9999 for TPOO and BTB methods, respectively. Limits of detection of the TPOO and BTB methods were 0.341 and 0.344 g/mL, respectively, and the limits of quantitation were 1.034 and 1.051 g/mL, respectively. Sandell's sensitivity and stability constant were also calculated. The proposed methods have been applied successfully for the analysis of the drug in its dosage forms. No interference was observed from excipients present in tablets. Statistical comparison of the results with those obtained by a high-performance liquid chromatography method showed excellent agreement and indicated no significant differences in accuracy and precision.

Spectrophotometric Methods for Simultaneous Determination of Sofosbuvir and Ledipasvir (HARVONI Tablet): Comparative Study with Two Generic Products

2017 ◽  
Vol 100 (4) ◽  
pp. 976-984 ◽  
Author(s):  
Nisreen F Abo-Talib ◽  
Mohamed R El-Ghobashy ◽  
Marwa H Tammam
Keyword(s):  
Dosage Form ◽  
Drug Dosage ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Drug Dosage Form ◽  
Generic Products ◽  
Third Derivative ◽  
Combination Pill

Abstract Sofosbuvir and ledipasvir are the first drugs in a combination pill to treat chronic hepatitis C virus. Simple, sensitive, and rapid spectrophotometric methods are presented for the determination of sofosbuvir and ledipasvir in their combined dosage form. These methods were based on direct measurement of ledipasvir at 333 nm (due to the lack of interference of sofosbuvir) over a concentration range of 4.0–14.0 µg/mL, with a mean recovery of 100.78 ± 0.64%. Sofosbuvir was determined, without prior separation, by third-derivative values at 281 nm; derivative ratio values at 265.8 nm utilizing 5.0 µg/mL ledipasvir as a divisor; the ratio difference method using values at 270 and 250 nm using 5.0 µg/mL ledipasvir as a divisor; and the ratio subtraction method using values at 261 nm. These methods were found to be linear for sofosbuvir over a concentration range of 5.0–35.0 µg/mL. The suggested methods were validated according to International Conference on Harmonization guidelines. Statistical analysis of the results showed no significant difference between the proposed methods and the manufacturer's LC method of determination with respect to accuracy and precision. These methods were used to compare the equivalence of an innovator drug dosage form and two generic drug dosage forms of the same strength.

scholarly journals Rapid Gas Chromatographic Method for Simultaneous Determination of Cholesterol and α-Tocopherol in Eggs

1998 ◽  
Vol 81 (6) ◽  
pp. 1177-1184 ◽  
Author(s):  
Nickos Botsoglou ◽  
Dimitrios Fletouris ◽  
Ioannis Psomas ◽  
Antonios Mantis
Keyword(s):  
Simultaneous Determination ◽  
Chromatographic Method ◽  
Labor Cost ◽  
Precision Data ◽  
Total Analysis Time ◽  
Accuracy And Precision ◽  
Relative Standard ◽  
Total Analysis ◽  
Gas Chromatographic Method

Abstract A new method was developed for simultaneous determination of cholesterol and α-tocopherol in eggs. It involves rapid and simple sample preparation accomplished in one tube and chromatographic separation that does not require derivatization of analytes. Total analysis time per sample is 40 min. Labor, cost, and use of hazardous chemicals are minimized. To ensure selectivity, accuracy, and precision, critical analytical parameters were investigated. Overall recoveries were 98.8 and 99.2% for cholesterol and α-tocopherol, respectively. Linearity was acceptable for both analytes (r = 0.9964 for cholesterol and 0.9996 for α-tocopherol) in the fortification range examined. Precision data based on within-day and between-days variation gave overall relative standard deviations of 2.0% for cholesterol and 7.0% for α-tocopherol.The method was applied successfully for quantitation of cholesterol and α-tocopherol in eggs.

scholarly journals Simple Atomic Absorption Spectroscopic and Spectrophotometric Methods for Determination of Pioglitazone Hydrochloride and Carvedilol in Pharmaceutical Dosage Forms

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Afaf A. Abdelmonem ◽  
Gamal H. Ragab ◽  
Hisham Hashem ◽  
Eman A. Bahgat
Keyword(s):  
Atomic Absorption ◽  
Acidic Medium ◽  
Methylene Chloride ◽  
Ion Pair ◽  
Fast Green ◽  
Experimental Conditions ◽  
Pharmaceutical Dosage Forms ◽  
Spectrophotometric Methods ◽  
Orange G

This study represents simple atomic absorption spectroscopic and spectrophotometric methods for determination of pioglitazone hydrochloride (PGZ-HCl) and carvedilol (CRV) based on formation of ion-pair associates between drugs and inorganic complex, bismuth(III) tetraiodide (Method A) and between drugs and organic acidic dyes, fast green and orange G (Method B). Method A is based on formation of ion-pair associate between drugs and bismuth(III) tetraiodide in acidic medium to form orange-red ion-pair associates, which can be quantitatively determined by two different procedures. The formed ion-pair associate is extracted by methylene chloride, dissolved in acetone, dried, and then decomposed by hydrochloric acid, and bismuth content is determined by direct atomic absorption spectrometric technique (Procedure 1) or extracted by methylene chloride, dissolved in acetone, and quantified spectrophotometrically at 490 nm (Procedure 2). Method B is based on formation of ion-pair associate between drugs and either fast green dye or orange G dye in acidic medium to form ion-pair associates. The formed ion-pair associate is extracted by methylene chloride and quantified spectrophotometrically at 630 nm (for fast green dye method) or 498 nm (for orange G dye method). Optimal experimental conditions have been studied. Both methods are applied for determination of the drugs in tablets without interference.

scholarly journals An Indirect Atomic Absorption Spectrometric Determination of Trifluoperazine Hydrochloride in Pharmaceutical Formulations Based on Chelate Formation with Palladium(II)

2010 ◽  
Vol 7 (s1) ◽  
pp. S433-S441
Author(s):  
Ameen W. Qasim ◽  
Zuhair A. A. Khammas
Keyword(s):  
Atomic Absorption ◽  
Direct Determination ◽  
Pharmaceutical Formulations ◽  
Mean Value ◽  
Pharmaceutical Dosage Form ◽  
Accuracy And Precision ◽  
Standard Additions ◽  
Optimized Conditions ◽  
Atomic Absorption Spectrometric

A new application of an indirect atomic absorption spectrometric (AAS) method was offered for the assay of low concentration of trifluoperazine hydrochloride (TFPH) in pure and pharmaceutical dosage form with good accuracy and precision. The method is depended on the formation of metal complex between the drug (TFPH) and palladium(II) to form orange-yellowish product extractable in organic solvent prior to its aspiration into an air-acetylene flame and indirectly determined by AAS. Using AA responses, all experimental parameters such as, pH, concentration of palladium, reaction time, extraction time and phase ratio which affect the complexation and extraction of TFPH-Pd(II), have been investigated. Under optimized conditions, linearity was observed in the range of 0.5-17 μg mL-1with detection limit (S/N) of 0.038 μg mL-1, precision in range of 1.18-1.92%, accuracy as the %Erelof 2.4% and recoveries ranged from 101.7 to 104% with mean value of 102.4±0.135. The proposed method was applied for the determination of TFPH in the drug stelazine by both direct calibration and standard additions procedures and found to be 4.88 and 4.87 mg per unite, respectively compared with the stated value of 5 mg per unite. This method is also compared statistically with direct determination by using UV-Vis spectrophotometric technique which is preformed in our laboratory and found to be insignificant at 95% confidence level. All statistical calculations were implemented via the chemsoftware Minitab version 11.

Development and Single-Laboratory Validation of an Improved Method for the Determination of Cyclamate in Foods Using Liquid Chromatography/Tandem Mass Spectrometry

2014 ◽  
Vol 97 (6) ◽  
pp. 1651-1655 ◽  
Author(s):  
Romina Shah ◽  
Lowri S De Jager ◽  
Timothy H Begley
Keyword(s):  
Internal Standard ◽  
Pomegranate Juice ◽  
Spectral Determination ◽  
Precision Data ◽  
Mass Spectral ◽  
Minimal Sample ◽  
Accuracy And Precision ◽  
Liquid Chromatography Tandem Mass ◽  
Potential Matrix

Abstract A fast and reliable LC-MS/MS method for the determination of cyclamate in a variety of food matrices was developed and validated. This method provides both quantitation and qualitative mass spectral determination important for analysis of regulatory samples. Utilization of a cyclamate-d11 internal standard corrects for potential matrix interferences during sample injection and allows minimal sample preparation. Seventeen commercially available food products were fortified at 250 μg/mL and tested as part of the method validation. Recoveries ranged from 72 to 110%, with RSDs ranging from 3 to 15%. The linear range spanned 0.010–1.00 μg/mL. LODs were 0.1 and 0.6 ng/mL, determined in pomegranate juice and dried fig, respectively. LOQs were 0.3 and 1.6 ng/mL, which are significantly lower than needed to measure cyclamate when used as a food additive. The interday and intraday accuracy and precision data are presented. This method was validated for analysis of a variety of commonly adulterated products, including drinks, dried fruits, jams, and hard candies.

scholarly journals Simple Methods for the Spectrophotometric Determination of Carvedilol

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Divya N. Shetty ◽  
B. Narayana
Keyword(s):  
Charge Transfer ◽  
Complex Formation ◽  
Confidence Level ◽  
Charge Transfer Complex ◽  
Condensation Reaction ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision

Two simple spectrophotometric methods are described for the determination of carvedilol (CAR). Method A is the condensation reaction of CAR with p-dimethylaminobenzaldehyde (PDAB), and the reaction mixture exhibits maximum absorbance at 601 nm. Method B is based on the charge transfer complex formation of CAR with p-chloranil; the color developed is measured at 662 nm. The calibration graphs are found to be linear over 50.00–250.00 and 20.00–100.0 μg mL−1 with molar absorptivity values of 0.92×103 and 0.257×104 L mol−1cm−1 for CAR-PDAB and CAR-p-chloranil, respectively. Statistical comparisons of the results are performed with regard to accuracy and precision using Student’s t-test and F-test at 95% confidence level. The methods are successfully employed for the determination of CAR in pharmaceutical preparations, and the results agree favorably with the reference and proposed methods.

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