scholarly journals Determination of the limit of quantification of the calorimeter using a mixture of benzoic acid and silicon dioxide

2011 ◽  
Vol 65 (1) ◽  
pp. 93-97
Author(s):  
Vesna Krstic ◽  
Branko Blagojevic ◽  
Lidija Gomidzelovic ◽  
Emina Pozega ◽  
Jelena Petrovic ◽  
...  

In recent years quality control has received a great attention in laboratory work. Implementation of the international standard ISO/IEC 17025 is necessary for any laboratory that wishes to establish quality control in its work. One of the important factors for meeting the requirements of this standard is the usage of the certified reference materials (CRM) in laboratory work. In order to determine the performance of the calorimeter, benzoic acid as CRM, from AlliedSignal Riedelda Haen, Ref.: 33045 and SiO2, Pro analyze, in various mass ratios was used. The results showed that benzoic acid can be successfully utilized for the control of the entire technical and instrumental measuring range and resolve the problem of determination of the limit of detection and quantification of the calorimeter.

Author(s):  
Anna Jeżewska

Propane-1,3-sultone (PS) is an alkylating substance used in the production of polymers, fungicides, insecticides, dyes, and detergents. It is absorbed into the human body by inhalation, digestion, and through the skin; it is also a possible carcinogen. Occupational exposure to this substance may occur on industrial or laboratory contact. In Poland, the maximum allowable concentration (MAC) for PS in workplace air is 7 µg/m3. The paper presents a method for determination of PS in workplace air using a gas chromatograph coupled with a mass spectrometer (GC-MS). Air containing PS is passed through a glass tube containing a glass fiber filter and two layers of silica gel. The substance is washed with acetonitrile and the solution obtained analysed using GC-MS. The measuring range for an air sample of 360 L is 0.7 ÷ 14 µg/m3. The limit of detection (LOD) is 13 ng/m3, limit of quantification (LOQ) is 40 ng/m3.


Author(s):  
Ankita Panchal ◽  
Gaurav Sanghvi ◽  
Ashish Vachhani ◽  
Navin Sheth ◽  
Devendra Vaishnav

A simple, sensitive, specific, and cost effective method for simultaneous determination of Aspirin and Rosuvastatin calcium was developed and validated in single dosage formulation. The sample solution of ASP and RSTC was prepared using methanol as a solvent. Separation of ASP and RSTC was achieved with a mobile phase consisting of 20 mM KH2PO4 : Methanol (30:70 v/v) at a flow rate of 1.0 ml/min. Separations were performed on Merck hibar 250-4.6 RP18 (5 µm) column (150 mm X 3.0 mm), using a Shimadzu Prominence HPLC system equipped with a Shimadzu SPD-20A detector, Rhenodyne 7725i injector with 20 μL loop, LC-20 AD pump, CBM-20 Alite controller and LC Solution software. Retention times of ASP and RSTC were 3.747 and 5.969 minutes respectively. Absolute recovery of ASP and RSTC was 100.3 and 100.03 % respectively. The lower limit of quantification (LLOQ) of ASP and RSTC was 0.3097 and 0.1063 ppm and lower limit of detection (LLOD) of ASP and RSTC was 0.01535 and 0.01358 ppm respectively. Linearity was established for the range of concentrations 15.00-90.0 μg/ml and 2.0-12.0 μg/ml for ASP and RSTC respectively with the coefficient of determination (R2) of 0.994 and 0.999 for both the compounds. The inter- and intra-day precision in the measurement of ASP quality control (QC) sample 75 μg/ml, were in the range 0.1-0.2 % relative standard deviation (R.S.D.) and 0.2-0.3 % R.S.D., respectively. The inter- and intra-day precision in the measurement of RST quality control (QC) sample 10 μg/ml, were in the range 0.1-0.2 % R.S.D., and 0.0-0.3 % R.S.D., respectively. The developed method would be applicable for routine quality control of ASP And RSTC in bulk as well as in pharmaceutical formulations


2019 ◽  
Vol 31 (9) ◽  
pp. 1985-1988
Author(s):  
Indah Hairunisa ◽  
Muhammad Da'i ◽  
Erindyah Retno Wikantyasning ◽  
Andhika Rizky Gilang Mahaputra ◽  
Normaidah Normaidah ◽  
...  

Determination of major bioactive compounds in polyphyto-formulation is important for production of standardized herbal products. A fast, simple and inexpensive method for detection and quantification of andrographolide concentration in nanoemulsion preparations containing a combination of Andrographis paniculata (Burm f.) Ness. and Phyllanthus niruri L. has been developed. Detection and quantification were carried out using UV-vis spectrophotometry analysis with picric acid reagent and NaOH (8:2) in methanol solvents, read at maximum wavelength 479 nm with 22 min of incubation time. Validation was done by determine the parameters such as linearity, intra and interday precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ). The results obtained showed linearity with r = 0.9945 (y = 0.0109x − 0.2066) in the range of 30-80 μg/mL. The accuracy (recovery) varied in the range of 97.15 to 104.42 %. Percentage of relative standard deviation (% RSD) for precision and intermediate precision value were 3.23 and 3.02 % with LOD value 211 μg/mL and the LOQ 705 μg/mL. As a conclusion, this method is suitable to detect andrographolide content in herbal nano-preparation.


Author(s):  
Dobrina Tsvetkova ◽  
Danka Obreshkova ◽  
Stefka Ivanova ◽  
Vladimir Yankov ◽  
Peter Atanasov ◽  
...  

The aim of current study was to validate spectrophotometric method with UV-detection for identification and determination of Telmisartan in 99.8 % ethanol in respect of analytical parameters: selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision (repeatability). For Telmisartan in 99.8 % еthanol at λ max = 298 nm for A1%1cm and ε the obtained results for А > 0.2 and А < 0.2 are: 1) А > 0.2: at 3.10–6 g/ml ÷ 1.25.10–5 g/ml; A1%1cm: 725 ÷ 823; ε: 37347 ÷ 423352) А < 0.2: at 2.5.10–7 g/ml ÷ 1.10–6 g/ml; A1%1cm: 1201 ÷ 1567; ε: 61816 ÷ 80651 Analytical parameter accuracy is represented by the degree of recovery, which in the corresponding confidence possibility suit the confidence interval: R СТ60: 100.31 % ÷ 102.05 %; R СТ80: 99.22 % ÷ 103.18 %; R СТ100 : 93.58 % ÷ 101.9 %. For precision is proved that all results for the quantities correspond to the relevant confidence interval: СТ60: 60.31 mg ÷ 60.77 mg; СТ80: 79.82 mg ÷ 82.18 mg; СТ100: 94.22 mg ÷ 101.58 mg.


2021 ◽  
Vol 18 ◽  
pp. 40-48
Author(s):  
Saad Antakli ◽  
Leon Nejem ◽  
Monzer Alraii

Simple and rapid spectrophotometric method was developed and applied to determine Glibenclamide (GB) by zero spectrophotometric method and first derivative spectrophotometric method for determining of (GB) in the presence of Metformin hydrochloride (MET). Zero spectrophotometric (ZS) method was applied for the determination of (GB) at λmax = 300 nm. Linearity range was (4 – 360) μg/mL. Regression analysis showed a good correlation coefficients R2 = 0.99993. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.65 μg/mL and 2.31 μg/mL, respectively.  First derivative spectrophotometric (1DS) method was applied for the determination of (GB) in the presence (MET). (GB) was determined at 317 nm (1D317). Linearity ranges were (4 – 240) μg/mL for (GB). Regression analysis showed a good correlation coefficients R2 = 0.999914. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.60 μg/mL and 1.83 μg/mL for (GB). The proposed zero spectrophotometry method was applied to analysis individual (GB), and the derivative (1D317) method was applied to analysis (GB) individually or combined with (MET) in Syrian trademark drugs. The proposed method is simple, direct, sensitive and do not require any extraction process. Thus, this method could be readily applicable for the quality control and routine analysis.


2012 ◽  
Vol 2 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Nia Kristiningrum ◽  
Mia Rakhmawati

A rapid and reproducible TLC method was developed for the determination of hydrocortisone acetate and chloramphenicol in cream. The analytes were dissolved with methanol and chromatographed on silica Gel GF 254 TLC plate using chloroform:ethyl acetate in the ratio of 1:1.5 (v/v) as mobile phase. Spots at Rf 0.29 and Rf 0.59 were recognized as chloramphenicol and hydrocortisone acetate, respectively. Quantitative analysis was done through densitometric measurement at wavelength 265 nm. Method was found linear over the concentration range of 300-900 ng/spot with the correlation coefficient of 0.999 and 0.998 for hydrocortisone acetate and chloramphenicol, respectively. Specificity showed calculation of purity and identity more than 0.99. The limit of detection (LOD) and the limit of quantification (LOQ) of the method were 23.84 and 71.51 ng/spot for hydrocortisone acetate, 21.06 and 63.18 ng/spot for chloramphenicol. The precision of this method was less than 2.8% whereas the means of the recovery data were 100.40± 0.579% for hydrocortisone acetate and 100.24±1.20% for chloramphenicol. The proposed method has been applied to the determination of hydrocortisone acetate and chloramphenicol in commercial cream formulations and the recovery of label claim were 99.23±0.66% (chloramphenicol) and 99.25±0.41% (hydrocortisone acetate) for brand A and 100.32±0.87% (chloramphenicol) and 100.53±0.78% (hydrocortisone acetate) for brand B. The developed method was successfully used for the assay of hydrocortisone acetate and chloramphenicol. The method is simple, sensitive and precise; it can be used for the routine quality control testing of marketed formulations.DOI: http://dx.doi.org/10.3329/icpj.v2i1.12871 International Current Pharmaceutical Journal 2012, 2(1): 7-10 


2018 ◽  
Vol 6 (6) ◽  
pp. 7-14
Author(s):  
Abdalla Ahmed Elbashir ◽  
Shahd Moutasim Merghani

A new, simple and sensitive spectrophotometric method is developed for the determination of ranitidine hydrochloride (RNH). The proposed method is based upon reaction of RNH with 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer of pH 8.0 producing an absorption maximum at 255 nm. All parameters required for the reaction conditions are investigated. Linearity is verified with a range of 2-16 μg/mL and is described by the regression equation y = 61129 x + 0.0354 with a correlation coefficient of 0.9998 (n = 7). The limit of detection (LOD) and the limit of quantification (LOQ) were calculated as per ICH guidelines and were found to be 0.2219 and 0.6724 μg/mL, respectively. The method was successfully applied for the determination of RNH in pharmaceutical formulation. Therefore, the method can be used for routine analysis of RNH in quality control laboratories.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Diego F. Coêlho ◽  
Thais Peron Saturnino ◽  
Fernanda Freitas Fernandes ◽  
Priscila Gava Mazzola ◽  
Edgar Silveira ◽  
...  

Given the importance of protease’s worldwide market, the determination of optimum conditions and the development of a standard protocol are critical during selection of a reliable method to determine its bioactivity. This paper uses quality control theory to validate a modified version of a method proposed by Charney and Tomarelli in 1947. The results obtained showed that using azocasein substrate bromelain had its optimum at 45°C and pH 9 (Glycine-NaOH 100 mM). We also quantified the limit of detection (LoD) and limit of quantification (LoQ) in the above-mentioned optimum (0.072 and 0.494 mg·mL−1of azocasein, resp.) and a calibration curve that correlates optical density with the amount of substrate digested. In all analysed samples, we observed a significant decrease in response after storage (around 17%), which suggests its use must be immediately after preparation. Thus, the protocol presented in this paper offers a significant improvement, given that subjective definitions are commonly used in the literature and this simple mathematical approach makes it clear and concise.


2015 ◽  
Vol 34 (2) ◽  
pp. 321 ◽  
Author(s):  
Tushar Dhanani ◽  
Sonal Shah ◽  
Satyanshu Kumar

A validated rapid and simple isocratic HPLC-PDA method was developed for identification and quantification of p- hydroxy benzoic acid and two iridoids negundoside and agnuside in the extracts of two Vitex species, Vitex negundo and Vitex trifolia. The separation of the three compounds was achieved on a RP-18 (250 mm X 4 mm, 5µm) column at 25o C using acetonitrile (15%) and 0.05% trifluoroacetic acid (TFA) in water (85%). Limit of detection (LOD) were 1, 2.5 and 2.5 μg/ml for p- hydroxy benzoic acid, negundoside and agnuside respectively. Similarly, limit of quantification (LOQ) were 2.5, 5 and 5 μg/ml for p- hydroxy benzoic acid, negundoside and agnuside respectively. Good linearity (r2 &gt; 0.999) was observed for all the three compounds in wide concentration range. Using the developed HPLC method, the three compounds were identified and quantified in leaves and bark extracts of Vitex negundo and Vitex trifolia. The novelty of the developed HPLC method is that it does not require complex sample processing such as use of solid phase extraction as well as use of buffer in mobile phase. This is the first report of a validated HPLC method for the simultaneous determination of p- hydroxy benzoic acid, negundoside and agnuside in Vitex species.


2019 ◽  
Vol 7 (1) ◽  
pp. 19-23
Author(s):  
Abdalla Ahmed Elbashir ◽  
Omnia Mohamed Abdallah alfaki

A new, simple, selective, precise and accurate spectrophotometric method for the determination of metformin in pharmaceutical formulation was developed and validated. The method was based on the reaction between metformin and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) at alkaline medium (pH 12.0) to form brown adduct.  Beer’s law was obeyed in the concentration range of 20-100 μg mL-1  of  metformin at maximum wave length 465 nm . Under the optimized reaction conditions, the linear regression equation of the calibration curve was found to be y=0.003x +0.156 with a linear correlation coefficient (r=0.999). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 5.8, 17.5 μg mL-1 respectively. The method is useful for routine analysis of metformin in quality control laboratories.


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