scholarly journals Method validation and measurement uncertainty of possible thirty volatile organic compounds (VOCs) presented in the polyethylene present in bottled drinking waters sold in Turkey

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Barış Güzel ◽  
Oltan Canli

Abstract This study was actualized for the simultaneous determination of possible thirty VOCs presented in drinking waters in Turkey by direct injection to purge and trap (PT) gas chromatography-mass spectrometry (GC-MS). It consists of selectivity, linearity, the limit of detection (LOD) and limit of quantification (LOQ), accuracy (recovery), precision, trueness, and measurement uncertainty studies. In linearity, the values of correlation coefficients (r2) for the matrix-matched calibration curves were higher than 0.998 for all analytes. This method showed high sensitivity (LOD: 0.011–0.040 μg/L; LOQ: 0.035–0.133 μg/L), quite sufficient recovery (82.6% to 103.1%) for accuracy, and acceptable precision (intra-day recovery: 81.5–104.4%, relative standard deviation (RSD): 1.04–9.81%; inter-day recovery: 92.6–104.1%, RSD: 1.15–7.52%). All the recovery and RSD values obtained below 10% are evaluated agreeable in point of the AOAC and EURACHEM/CITAC validation guidelines. The recovery percentages of all analytes in CRM changed between 80.3 and 109.9% and the RSD (%) values for each analyte obtained below 10%. The proficiency test results were satisfactory and comparable (z score less than or equal to 2.0 is no questionable or satisfactory) to those obtained by other laboratories participating in the round. The calculated percentage of relative uncertainties for each analyte changed from 2.99 to 10.10% and the major contribution to uncertainty budget arises from the calibration curve and repeatability. Therefore, the results demonstrate that this method is applicable for the determination of possible thirty VOCs in drinking waters in routine analysis for custom laboratories.

2021 ◽  
Vol 1162 ◽  
pp. 101-108
Author(s):  
Yuli Rohyami ◽  
Toni Aprianto ◽  
Marjono

The validation method for determination of chemical oxygen demand (COD) with indirect UV-Vis spectrometry have been done. This method enable to easily perform highly sensitive, considerably faster and easier, and minimize the use of digestion solution. This method is the development of standard method of COD determination by closed reflux using UV-Vis spectrometry so it requires the method validation stage. The validation is used to ensure linearity, limit of detection, limit of quantification, precision, and accuracy values in accordance with quality control. This study was also carried out to formulate the uncertainty calculation modeling of COD on water analysis. The result of validation method show that the calibration curve linearity is 0.9994 with the linear regression equation Y = 0.0003X + 0.0005. The method is able to have high sensitivity in measuring COD value with low concentrations with limit of detection and limit of quantitation of 9.78 and 32.59 mg O2/L. Indirect UV-Vis spectrometry has high precision with relative standard deviation of 0.66% and high accuracy with the percentage of recovery of 91.35%. The uncertainty formulation model on determination of COD from the source of standard uncertainty of sample volume, calibration curves, and repeatability.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Indhu Priya Mabbu ◽  
G. Sumathi ◽  
N. Devanna

Abstract Background The aim of the present method is to develop and validate a specific, sensitive, precise, and accurate liquid chromatography-mass spectrometry (LC-MS) method for the estimation of the phenyl vinyl sulfone in the eletriptan hydrobromide. The effective separation of the phenyl vinyl sulfone was achieved by the Symmetry C18 (50 × 4.6 mm, 3.5 μm) column and a mobile phase composition of 0.1%v/v ammonia buffer to methanol (5:95 v/v), using 0.45 ml/min flow rate and 20 μl of injection volume, with methanol used as diluent. The phenyl vinyl sulfone was monitored on atomic pressure chemical ionization mode mass spectrometer with positive polarity mode. Results The retention time of phenyl vinyl sulfone was found at 2.13 min. The limit of detection (LOD) and limit of quantification (LOQ) were observed at 1.43 ppm and 4.77 ppm concentration respectively; the linear range was found in the concentration ranges from 4.77 to 27.00 ppm with regression coefficient of 0.9990 and accuracy in the range of 97.50–102.10%. The percentage relative standard deviation (% RSD) for six replicates said to be injections were less than 10%. Conclusion The proposed method was validated successfully as per ICH guidelines. Hence, this is employed for the determination of phenyl vinyl sulfone in the eletriptan hydrobromide.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1837
Author(s):  
Harischandra Naik Rathod ◽  
Bheemanna Mallappa ◽  
Pallavi Malenahalli Sidramappa ◽  
Chandra Sekhara Reddy Vennapusa ◽  
Pavankumar Kamin ◽  
...  

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg−1 for Capsicum and 0.10 to 9.55 µg·kg−1 (LOD) and 0.35 to 33.43 µg·kg−1 (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSDwR) by spiking of mixed pesticides standards at 100 µg·kg−1 recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.


2003 ◽  
Vol 68 (8-9) ◽  
pp. 691-698 ◽  
Author(s):  
Milena Jelikic-Stankov ◽  
Predrag Djurdjevic ◽  
Dejan Stankov

In this work a new enzymatic method for the determination of uric acid in human serum has been developed. The method is based on the oxidative coupling reaction between the N-methyl-N-(4-aminophenyl)-3-methoxyaniline (NCP) reagent and the hydrogen ? donor reagent N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline (TOOS), in the system involving three enzymes: uricase, peroxidase and ascorbate oxidase. Using this method uric acid could be determined in concentrations up to 1.428 mmol/L, with a relative standard deviation of up to 1.8 %. The effect of the medium pH and the NCP concentration on the linearity of the chromogen absorbance versus the uric acid concentration curve was investigated. The influence of the uricase activity on the maximum rate of uric acid oxidation was also examined. The use of the NCP reagent demonstrated a more precise and more sensitive determination of the uric acid compared to the determination with 4-aminoantipyrine (4-AA) as the coupling regent. The sensitivity of the method determined from the calibration curve was 0.71 absorbance units per mmol/L of uric acid; the limit of detection was LOD = 0.0035 mmol/L and the limit of quantification was LOQ = 0.015 mmol/L of uric acid.


2015 ◽  
Vol 12 (1) ◽  
pp. 167-177 ◽  
Author(s):  
Baghdad Science Journal

A spectrophotometric method has been proposed for the determination of two drugs containing phenol group [phenylephrine hydrochloride (PHP) and salbutamol sulphate (SLB)] in pharmaceutical dosage forms. The method is based on the diazotization reaction of metoclopramide hydrochloride (MCP) and coupling of the diazotized reagent with drugs in alkaline medium to give intense orange colored product (?max at 470 nm for each of PHP and SLB). Variable parameters such as temperature, reaction time and concentration of the reactants have been analyzed and optimized. Under the proposed optimum condition, Beer’s law was obeyed in the concentration range of 1-32 and 1-14 ?g mL-1 for PHP and SLB, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for each of PHP and SLB were 0.60, 0.52 ?g mL-1 and 2.02, 1.72 ?g mL-1, respectively. No interference was observed from common excipients present in pharmaceutical preparations. The good correlation coefficients and low relative standard deviation assert the applicability of this method. The suggested method was further applied for the determinations of drugs in commercial pharmaceutical preparations, which was compared statistically with reference methods by means of t- test and F- test and were found not to differ significantly at 95% confidence level. The procedure was characterized by its simplicity with accuracy and precision.


2013 ◽  
Vol 3 (1) ◽  
pp. 208-210
Author(s):  
Nia Kristiningrum ◽  
Ellsy Novita Martyanti

A rapid, reproducible and accurate TLC method was developed for the determination of Cetirizine Dihydrochloride in tablet. The analytes were dissolved with ethanol 70% and chromatographed on silica Gel GF 254 TLC plate using chloroform : methanol : ethyl acetate in the ratio of 2 : 7 : 3 (v/v) as mobile phase. Quantitative analysis was done through densitometric measurement at wavelength 234 nm. Method was found linear over the concentration range of 400 – 1600 ng/spot with the correlation coefficient of 0.996. 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 75.54 and 226.64 ng/spot. The relative standard deviation of this method was 0.86% whereas the means of the recovery data was 100.54 ± 0.11%. The proposed method has been applied to the determination of Cetirizine Dihydrochloride in commercial tablet formulations and the result were 96.97 ± 0.86 % for brand A and 100.57 ± 1.17 % for brand B. The developed method was successfully used for the assay of Cetirizine Dihydrochloride. This 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.v3i1.17294 International Current Pharmaceutical Journal, December 2013, 3(1): 208-210


2018 ◽  
Vol 5 (4) ◽  
pp. 172128 ◽  
Author(s):  
Ming Ding ◽  
Kailiang Wang

A practical method for the determination of cyanide in bamboo shoots has been developed using microdiffusion preparation integrated with ion chromatography–pulsed amperometric detection (IC-PAD). Cyanide was released from bamboo shoots after Conway cell microdiffusion, and then analysed by IC-PAD. In comparison with the previously reported methods, derivatization and ion-pairing agent addition were not required in this proposed microdiffusion combined with IC-PAD method. The microdiffusion parameters were optimized including hydrolysis systems, temperature, time, and so on. Under the optimum conditions, the linear range of the calibration curve for cyanide was 0.2–200.0 µg kg −1 with satisfactory correlation coefficients of 0.9996 and the limit of detection was 0.2 µg kg −1 ( S/N  = 3). The spiked recovery range was from 92.8 to 98.6%. The intra-day and inter-day relative standard deviations of cyanide were 2.7–14.9% and 3.0–18.3%, respectively. This method was proved to be convenient in operation with high sensitivity, precision and accuracy, and was successfully applied in the determination of cyanide in bamboo shoot samples.


2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Neelkant Prasad ◽  
Roshan Issarani ◽  
Badri Prakash Nagori

A simple and sensitive ultraviolet spectrophotometric method for quantitative estimation of glipizide in presence of lipid turbidity is described to avoid false estimation due to diffraction by turbidity. UV detection was performed at 230 nm, 225 nm, and 235 nm, and the calibration curve was plotted between resultant of absorbance of [230 nm − (225 nm + 235 nm)/2] and concentration of analyte. The calibration curve was linear over the concentration range tested (1–20 μg/mL) with limit of detection of 0.27 μg/mL and limit of quantification of 0.82 μg/mL. Percent relative standard deviations and percent relative mean error, representing precision and accuracy, respectively, for clear as well as turbid solutions, were found to be within acceptable limits, that is, always less than 0.69 and 0.41, respectively, for clear solution and 0.65 and 0.47, respectively, for turbid solution. Conclusively, our method was successfully applied for the determination of glipizide in clear as well as turbid solutions, and it was found that the drug analyte in both types of solutions can be detected from the same calibration curve accurately and precisely and glipizide entrapped in the liposomes or in proliposomal matrix was not detected.


Author(s):  
DAVID ALEXANDER ◽  
Abdul Rohman

Objective: The aim of this research was to validate inductively coupled plasma-atomic emission spectroscopy (ICP-AES) for quantitative analysis of cadmium (Cd), chromium (Cr), cuprum (Cu), mangan (Mn) and nickel (Ni) in milk products. Methods: The heavy metals in milk were determined using ICP-AES at optimized wavelength. The method was validated by assessing several validation parameters which included linearity and range, accuracy, precision and sensitivity expressed by the limit of detection and limit of quantification. The validated method was then used for the analysis of milks commercially available. Results: ICP-AES for determination of Cd, Cr, Cu, Mn, and Ni was linear over a certain concentration range with a coefficient correlation value of>0.997. The limit of quantification values of Cd, Cr, Cu, Mn, and Ni were 0.0047; 0.0050; 0.0066; 0.0061; and 0.0169 µg/ml, respectively. The precision of analytical method exhibited relative standard deviation (RSD) values of 3.18%; 4.17%; 3.05%; 2.93%; and 4.47% during repeatability test and 5.28%; 5.06%; 3.67%; 3.67%; and 11.17% during intermediate precision of Cd, Cr, Cu, Mn, and Ni respectively. The recoveries of these metals assessed using standard addition method were 92.25; 90.88; 102.87; 94.50; and 86.85%, respectively. Conclusion: ICP-AES offered a reliable and fast method for the determination of heavy metals in milk products. The developed method could be proposed as an official method for determination of heavy metals in milk products.


Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 552
Author(s):  
Shun-Yu Han ◽  
Lan-Lan Hao ◽  
Xiao Shi ◽  
Jian-Ming Niu ◽  
Bo Zhang

The aim of this study was to develop and validate an improved, simple, and sensitive method for the simultaneous determination of seven types (cadaverine, CAD; hexylamine, HEX; histamine, HIS; phenylethylamine, PEA; putrescine, PUT; tyramine, TYR) of biogenic amines (BAs) in wine matrices. For this reason, a modified QuEChERS combined with ultra-performance liquid chromatography coupled to a triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) method was investigated. The optimization of UHPLC-QqQ-MS/MS separation and QuEChERS procedure was performed. Under optimum conditions, the excellent chromatographic performance of the whole separation was accomplished within 6.3 min analyzing time. Meanwhile, the recoveries ranged from 77.2% to 101.7%, while relative standard deviation (RSD) remained between 0.0% and 9.4%. The limit of detection (LOD, 0.50–1.00 µg/L) and the limit of quantification (LOQ, 1.65–3.30 µg/L) were lower than those permitted by legislation in food matrices, which demonstrated the high sensitivity and applicability of this efficient method. This validated method was also applied in a pilot study to analyze BAs in 81 wine samples from Hexi Corridor Region (Gansu Province, Northwest China), CAD, HEX, HIS, PEA, PUT, and TYR were detected to varying degrees in the samples. However, when compared with the existing standards, the BAs in all 81 wine samples did not exceed the prescribed limit value or toxic dose (2–40 mg/L). Moreover, a statistical approach was also conducted using Pearson correlation analysis, and to evaluate their concentrations in terms of wine parameters (storage time, grape variety, wine type, and basic physicochemical index). The results showed that, among the seven kinds of BAs, the concentration of HIS had a certain correlation with alcoholic degree and grape variety. In addition, the level of PEA had a certain correlation with the wine pH and wine storage time. It is worth noting that this seems to be the first report regarding the application of QuEChERS-UHPLC-QqQ-MS/MS in the analysis of BAs in wine in this region.


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