Evaluation of Monier-Williams and Committee Methods for Bisulfite Determination as Used by the Potato Processing Industry

1986 ◽  
Vol 69 (1) ◽  
pp. 11-14
Author(s):  
John G Moylan ◽  
F William Bowes ◽  
Walter J Pappin

Abstract The Monier-Williams and the iodometric Committee methods were evaluated for the determination of bisulfite in potato products. Both methods showed critical problems in accuracy and precision at concentrations below 60 ppm. Sensitivity levels of 25 ppm are possible with the Monier-Williams method. However, accuracy problems reflected by the coefficients of variation (Monier-Williams, 47.4%; Committee, 78.2%) as well as variability in recoveries and blank values for both methods produce qualitative rather than quantitative analytical data at low SO2 concentrations

1984 ◽  
Vol 67 (2) ◽  
pp. 284-289 ◽  
Author(s):  
James A Ault ◽  
Tim E Spurgeon ◽  
◽  
M M Anderson ◽  
R Bowers ◽  
...  

Abstract A gas chromatographic electron capture detector method is described for the quantitative determination of organochlorine pesticide residues in poultry fat. The samples are rendered and cleaned up using automated gel permeation chromatography. The collaborative samples consisted of 10 fortified samples and one incurred residue sample, all in duplicate. Fortification levels ranged from 0.15 to 1.0 ppm for a-BHC, lindane, cis- and frans-chlordane, octachlor epoxide, o,p' and p,p'-DDT, p,p'-DDE, p,p'-TDE, hexachlorobenzene, heptachlor epoxide, dieldrin, endrin, methoxychlor, mirex, and toxaphene. The average recovery was 91.9% with a range of 81-102%. The ranges of coefficients of variation were: CVo = 3.39-14.79%; CVL = 0-16.6%; and CVx = 5.82-19.0%. The results indicate accuracy and precision comparable to other official methodology. The method has been adopted official first action.


1988 ◽  
Vol 71 (2) ◽  
pp. 280-282
Author(s):  
Dilek Boyacioglu ◽  
Meral Gonul

Abstract A study was conducted to determine the accuracy and precision of 3 AOAC methods, sees 26.026-26.031 (CB), sees 26.032-26.036 (BF), and sees 26.052-26.060 (cottonseed), and the Romer quantitative method for the thin-layer chromatographic (TLC) determination of aflatoxins B„ B2, G„ and G2 in raisins. The samples were spiked at a level of 10 Mg total aflatoxins/kg. The TLC development systems were: ether-methanol-water (94 + 4.5 + 1.5) and chloroform-acetone (9 + 1). The interaction between the 4 methods and the 2 development systems was also studied. The average recoveries were 88, 80, 75, and 93% with coefficients of variation of 14.0,10.4,14.0, and 9.6% for aflatoxin B, using the CB, BF, cottonseed, and Romer methods, respectively. Statistical analysis showed no difference in the results obtained using the 2 TLC development systems


2006 ◽  
Vol 49 (spe) ◽  
pp. 41-46 ◽  
Author(s):  
Roseane Brandão de Brito ◽  
Roberto Gonçalves Junqueira

A high performance liquid chromatographic method to assay beta-lactam residues in milk was developed and validated. Milk samples were spiked with standard solutions and deproteinated. The extract was cleaned-up on C18 SPE cartridge, the antibiotics eluted with acetonitrile:water (50:50 v/v) and derivatized with acetic anhydride and 1-methyl-imidazole solution containing HgCl2. The chromatographic analysis was performed on C18 column using mobile phase consisting of acetonitrile and phosphate buffer (pH 6.5) in the presence of Na2S2O3 gradient and detection at 325 nm. The method was selective for ampicillin, penicillin G and penicillin V, the latter used as internal standard. Average recoveries for ampicillin and penicillin G ranged, respectively, from 60.0% to 104.9% and from 82.7% to 109.2%, with coefficients of variation from 11.1% to 24.6%, and from 2.1% to 25.2%, indicating accuracy and precision. Detection limit of 4.0 µg/L for ampicillin and 3.0 µg/L for penicillin G, and quantification limits of 4.0 µg/L for both were estimated.


1968 ◽  
Vol 22 (4) ◽  
pp. 283-285
Author(s):  
L. T. Kurtz ◽  
H. L. S. Tandon ◽  
E. C. Marcusiu

Fluoride greater than 0.1 N interfered negatively in the determination of Al by the rotatingdisk-electrode technique. Fluoride interference was eliminated by the addition of H3BO3. Aluminum in the 1–100 ppm range was successfully determined in the presence of 0.25 N fluoride by making the solutions 2.5% in H3BO3. The coefficients of variation among six determinations for solutions containing 10 and 100 ppm Al were 3.0% and 0.9%, respectively. Recovery of known amounts of Al added to fluoride-extracts of soils ranged from 98.4% to 102.2%. The proposed method thus gave acceptable accuracy and precision. The method is simple and rapid since it does not require the removal of fluoride by distillation as H2SiF0 nor does it prevent the determination of Si in the same sample.


2020 ◽  
Vol 23 (10) ◽  
pp. 1010-1022
Author(s):  
Emrah Dural

Aim and scope: Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey. Materials and Methods: Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes. Results: This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively. Conclusion: Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.


2020 ◽  
Vol 16 (6) ◽  
pp. 671-689
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Katarzyna Mądra-Gackowska ◽  
Piotr Kośliński ◽  
Stefan Kruszewski

At present, no one can imagine drug development, marketing and post-marketing without rigorous quality control at each stage. Only modern, selective, accurate and precise analytical methods for determination of active compounds, their degradation products and stability studies are able to assure the appropriate amount and purity of drugs administered every day to millions of patients all over the world. For routine control of drugs simple, economic, rapid and reliable methods are desirable. The major focus of current scrutiny is placed on high-performance thin layer chromatography and derivative spectrophotometry methods, which fulfill routine drug estimation’s expectations [1-4]. The present paper reveals state-of-the-art and possible applications of those methods in pharmaceutical analysis between 2010 and 2018. The review shows advantages of high-performance thin layer chromatography and derivative spectrophotometry, including accuracy and precision comparable to more expensive and time-consuming methods as well as additional fields of possible applications, which contribute to resolving many analytical problems in everyday laboratory practice.


2019 ◽  
Vol 15 (6) ◽  
pp. 635-641
Author(s):  
Nadia M. Mostafa ◽  
Ghada M. Elsayed ◽  
Nagiba Y. Hassan ◽  
Dina A. El Mously

Background:The concept of green analytical chemistry prevails due to the growing environmental pollution.Objective:Our attempts are to develop simple and eco-friendly method which is non-harmful to the environment by producing minimal waste. In this context, a green liquid chromatographic method was applied for the simultaneous determination of chlorpheniramine maleate, pseudoephedrine hydrochloride and propyphenazone in their combined dosage form.Methods:Separation was carried out using X select HSS RP C18 analytical column (250 × 4.6 mm, 5μm) using methanol - 0.02 M phosphate buffer pH 3 - triethylamine (60:40: 0.1, by volume) as a mobile phase. The separated peaks were detected at 215 nm at a flow rate 1.0 mL/min.Results:Quantification was done over the concentration ranges of 1-25 µg/mL for chlorpheniramine maleate, 5-35 µg/mL for pseudoephedrine hydrochloride and 10-120 µg/mL for propyphenazone. The suggested method was validated with regard to linearity, accuracy and precision according to the International Conference on Harmonization guidelines with good results.Conclusion:It could be used as a safer alternative for routine analysis of the mentioned drugs in quality control laboratories.


2020 ◽  
Vol 16 ◽  
Author(s):  
Aykut Kul ◽  
Murat Ozdemir ◽  
Selma Ozilhan ◽  
Olcay Sagirli

Background: Buprenorphine is quite common in the illicit market. Buprenorphine-containing drugs abuse is frequently encountered in patients. The analysis methods used to determine the abuse of buprenorphine and norbuprenorphine are important for forensic science. Buprenorphine is metabolized to norbuprenorphine by the liver. Objective: Therefore, the determination of buprenorphine and norbuprenorphine in urine is one of the methods to determine the abuse of buprenorphine. Methods: In this study, we have developed a precise, simple, and rapid ultra-performance liquid chromatographytandem mass spectrometer method for the determination of buprenorphine and norbuprenorphine simultaneously. Results: The developed method was validated in terms of selectivity and linearity, which was in the range of 9–1800 ng/mL for both buprenorphine and norbuprenorphine. The intra-assay and inter-assay accuracy and precision were found within acceptable limits of the EMA guideline. Lower limits of quantitation were 9 ng/mL for both buprenorphine and norbuprenorphine. Conclusion: The developed method was successfully applied for the determination of both analytes in the proficiency testing samples.


1975 ◽  
Vol 58 (5) ◽  
pp. 1051-1061
Author(s):  
William P Cochrane ◽  
James F Lawrence ◽  
Young W Lee ◽  
Ronald B Maybury ◽  
Brian P Wilson

Abstract An interlaboratory investigation of technical chlordane residues in food crops was carried out to determine the most practical and consistent method of reporting results. Using a technical chlordane reference standard, 8 gas chromatographic stationary phases were studied for their resolution capabilities. The best separations were obtained with SE-30 and its OV-1 equivalent. Using these columns and electron capture detection, potatoes and carrots from supervised field experiments were analyzed in duplicate and quantitated by using 4 methods of calculation. The data were statistically treated to determine the precision and bias for each method. Also, 1 sample was analyzed in duplicate on 2 different occasions by 6 laboratories to substantiate the initial conclusions. Based on the criterion of high precision it is suggested that a comparison of total area under the chromatogram of the sample with total area of a standard technical chlordane be the method of quantitation. Only peaks which are common to both standard and sample have any significance in this type of calculation.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4357
Author(s):  
Waritda Pookmanee ◽  
Siriwan Thongthip ◽  
Jeeranut Tankanitlert ◽  
Mathirut Mungthin ◽  
Chonlaphat Sukasem ◽  
...  

The method for the determination of primaquine (PQ) and 5,6-orthoquinone primaquine (5,6-PQ), the representative marker for PQ active metabolites, via CYP2D6 in human plasma and urine has been validated. All samples were extracted using acetonitrile for protein precipitation and analyzed using the ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) system. Chromatography separation was carried out using a Hypersil GOLDTM aQ C18 column (100 × 2.1 mm, particle size 1.9 μm) with a C18 guard column (4 × 3 mm) flowed with an isocratic mode of methanol, water, and acetonitrile in an optimal ratio at 0.4 mL/min. The retention times of 5,6-PQ and PQ in plasma and urine were 0.8 and 1.6 min, respectively. The method was validated according to the guideline. The linearity of the analytes was in the range of 25–1500 ng/mL. The matrix effect of PQ and 5,6-PQ ranged from 100% to 116% and from 87% to 104% for plasma, and from 87% to 89% and from 86% to 87% for urine, respectively. The recovery of PQ and 5,6-PQ ranged from 78% to 95% and form 80% to 98% for plasma, and from 102% to from 112% to 97% to 109% for urine, respectively. The accuracy and precision of PQ and 5,6-PQ in plasma and urine were within the acceptance criteria. The samples should be kept in the freezer (−80 °C) and analyzed within 7 days due to the metabolite stability. This validated UHPLC-MS/MS method was beneficial for a pharmacokinetic study in subjects receiving PQ.


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