scholarly journals Determination of 18 Intact Glucosinolates in Brassicaceae Vegetables by UHPLC-MS/MS: Comparing Tissue Disruption Methods for Sample Preparation

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 231
Author(s):  
Xiaolu Yu ◽  
Hongju He ◽  
Xuezhi Zhao ◽  
Guangmin Liu ◽  
Liping Hu ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Dry Weight ◽  
Microwave Treatment ◽  
Universal Method ◽  
Anticancer Activities ◽  
Fresh Sample ◽  
Freeze Dried ◽  
Relative Standard ◽  
Quantification Accuracy

Glucosinolates (GSLs) are important precursor compounds with anticancer activities in Brassicaceae vegetables and are readily hydrolyzed by myrosinase. Given the diversity of these species, establishing an accurate and universal method to quantify intact GSLs in different plant tissues is necessary. Here, we compared and optimized three tissue disruption methods for sample preparation. After microwave treatment for 90 s, 13 GSLs in homogenized Chinese cabbage samples were recovered at 73–124%. However, a limitation of this method was that different tissues could not be processed under the same microwave conditions. Regarding universality, GSLs in Brassicaceae vegetables could be extracted from freeze-dried sample powder with 70% methanol (v/v) or frozen-fresh sample powder with 80% methanol (v/v). Moreover, heating extraction is necessary for GSLs extracted from frozen-fresh sample powder. Average recoveries of the two optimized methods were 74–119% with relative standard deviations ≤15%, with the limits of quantification 5.72–17.40 nmol/g dry weight and 0.80–1.43 nmol/g fresh weight, respectively. Notably, the method for analyzing intact GSLs was more efficient than that for desulfo-GSLs regarding operational complexity, detection speed and quantification accuracy. The developed method was applied to identify the characteristic GSLs in 15 Brassicaceae vegetables, providing a foundation for further research on GSLs.

Microdiffusion and Fluoride-Specific Electrode Determination of Fluoride in Foods

1979 ◽  
Vol 62 (5) ◽  
pp. 1065-1069
Author(s):  
Robert W Dabeka ◽  
Arthur D Mckenzie ◽  
Henry B S Conacher
Keyword(s):  
Dry Weight ◽  
Accurate Method ◽  
Standard Reference Materials ◽  
Buffer Solution ◽  
Infant Foods ◽  
Freeze Dried ◽  
Relative Standard ◽  
Petri Dishes ◽  
Absorbent Layer

Abstract A simple and accurate method was developed for routine determination of fluoride in foods. Hydrogen fluoride is diffused 20 hr at 50°C from fresh or freeze-dried samples (0.1 g dry wt) in polystyrene petri dishes containing 2 mL 40% HClO4 and 0.3 g Ag2SO4, and is absorbed on the lids, previously spotted with 0.1 mL 0.5M NaOH. The absorbent layer is dissolved in 2 mL buffer solution, and the fluoride is measured potentiometrically. The method was verified by analysis of NBS Standard Reference Materials; recovery from 28 spiked infant foods (average = 99%, range — 75-135%); and comparison of results with colorimetry results for the same diffusates, after modification to handle 1 g samples. Relative standard deviations varied from 4 to 20% day to day. Detection limits were below 0.05 μg/g dry weight.

scholarly journals Germanium determination in environmental object by the method of mass spectrometry with inductively coupled plasma

2019 ◽  
Vol 85 (4) ◽  
pp. 110-113
Author(s):  
Olexandr Ponomarenko ◽  
Anatolyi Samchuk ◽  
Kateryna Vovk ◽  
Igor Shvaika ◽  
Ganna Grodzinskaya
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Inductively Coupled Plasma ◽  
Microwave Field ◽  
Antitumor Effects ◽  
Inductively Coupled ◽  
Ms Analysis ◽  
Icp Ms ◽  
Relative Standard

The analytical technologies of sample preparation of rocks and mushrooms using the microwave field for the determination of germanium by the method of mass spectrometry with inductively coupled plasma (ICP-MS analysis) have been developed. Germanium is a rare element. Germanium is homology of silicon and carbon. To date, the definition of low content of germanium in geological objects is a rather complex analytical task, which requires its concentration - extraction, co-precipitation, ion exchange. At present, the harmonious combination of the method of natural objects decomposition in the microwave field and germanium determination using ICP-MS analysis is particularly promising. Sample preparation of silicate rocks for ICP-MS determination of germanium was carried out by decomposition in a mixture of hydrofluoric, phosphate and nitric acids (5: 5: 2) in a microwave oven program at 240°C for 30 min. Sample preparation of mushrooms for ICP-MS germanium determination was carried out according to the following scheme. Initially, the dried sample was sealed in the presence of CaO, after dissolving it in a mixture of HNO3+HF+H3PO4 (6:6:1). Ge solution was extracted by Nazarenko V.A. extraction method. The developed analytical schemes have made it possible to significantly reduce the duration and labor intensity of sample preparation. The obtained solutions were analyzed using an inductively coupled plasma mass spectrometer. The developed method for determining germanium by ICP-MS analysis has been successfully tested on standard rock samples. The obtained results are in accordance with the accepted attribute, the relative standard deviation Sr ranges from 0.7-0.9. The data on the content and distribution of germanium in the Boletales fungi are obtained. They indicate wild mushrooms contain high levels of germanium, especially Boletus and Mushroom biospores. These studies are necessary because the essential properties of germanium and its compounds attract special attention of scientists today. Complementary Ge compounds which have hypotensive, bactericidal, antiviral and antitumor effects have already been synthesized.

High-Performance Liquid Chromatography Quantitative Determination of Oxyresveratrol and Morin Contained in Maclura cochinchinensis Extract and Gel Formulation

2021 ◽  
Vol 901 ◽  
pp. 79-85
Author(s):  
Arpa Petchsomrit ◽  
Boonyadist Vongsak
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Anticancer Activities ◽  
Limits Of Detection ◽  
Percent Recovery ◽  
Relative Standard ◽  
Traditional Drug ◽  
Detection And Quantification

Maclura cochinchinensis (Lour.) Corner., of the Moraceae family, is a medical shrub commonly found in Thailand, and for which a wide variety of pharmacological activities have been reported, including antiviral, anti-inflammatory, antioxidant, and anticancer activities. The main bioactive compounds, oxyresveratrol and morin, are known to be found in M. cochinchinensis heartwood. In this study, we quantitatively analyzed the levels of these two active substances in M. cochinchinensis extracted with various solvents, including in various cosmetic formulations and herbs sourced from various parts of Thailand. High-performance liquid chromatography (HPLC) was performed on a C18 column with an isocratic elution using 1.5% formic acid and acetonitrile at a flow rate of 1 ml/min, and detected at 352 nm. This method was validated for accuracy, precision, linearity, limits of detection, and quantification. The average percent recovery for oxyresveratrol and morin in the extracts was 100.01 ± 0.62% and 99.31 ± 2.56%, and in gel formulation was 99.65 ± 3.54% and 118.41 ± 4.70%, respectively. The relative standard deviation of intra- and inter-day precision was less than 2.0% and 2.8%, respectively. Limits of detection and quantification were 0.06 and 0.2 μg/ml, respectively. The amounts of oxyresveratrol and morin extracted from different solvents, such as acetone, 80% ethanol, 50% ethanol, methanol, and distilled water were in the range of 37.75–68.16 and 54.63–144.83 mg/g, respectively, while five samples of M. cochinchinensis heartwood collected from different regions of traditional drug stores contained in the range of 26.85–60.37 and 110.26–157.44 mg/g, respectively. Additionally, the percentage label amounts of oxyresveratrol and morin were analyzed in gel preparations, and found at 82.88% and 120.99%, respectively. This technique is convenient, simple, and reliable to effectively analyze the content of these active compounds in extracts and cosmetic products.

scholarly journals Simultaneous Determination of Crypto-Chlorogenic Acid, Isoquercetin, and Astragalin Contents inMoringa oleiferaLeaf Extracts by TLC-Densitometric Method

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Boonyadist Vongsak ◽  
Pongtip Sithisarn ◽  
Wandee Gritsanapan
Keyword(s):  
Chlorogenic Acid ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Dry Weight ◽  
Active Components ◽  
Leaf Extracts ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Layer Chromatography

Moringa oleiferaLamarck (Moringaceae) is used as a multipurpose medicinal plant for the treatment of various diseases. Isoquercetin, astragalin, and crypto-chlorogenic acid have been previously found to be major active components in the leaves of this plant. In this study, a thin-layer-chromatography (TLC-)densitometric method was developed and validated for simultaneous quantification of these major components in the 70% ethanolic extracts ofM. oleiferaleaves collected from 12 locations. The average amounts of crypto-chlorogenic acid, isoquercetin, and astragalin were found to be 0.0473, 0.0427, and 0.0534% dry weight, respectively. The method was validated for linearity, precision, accuracy, limit of detection, limit of quantitation, and robustness. The linearity was obtained in the range of 100–500 ng/spot with a correlation coefficient (r) over 0.9961. Intraday and interday precisions demonstrated relative standard deviations of less than 5%. The accuracy of the method was confirmed by determining the recovery. The average recoveries of each component from the extracts were in the range of 98.28 to 99.65%. Additionally, the leaves from Chiang Mai province contained the highest amounts of all active components. The proposed TLC-densitometric method was simple, accurate, precise, and cost-effective for routine quality controlling ofM. oleiferaleaf extracts.

scholarly journals Determination of β-Carotene in Commercial Foods: Interlaboratory Study

1997 ◽  
Vol 80 (5) ◽  
pp. 1057-1064 ◽  
Author(s):  
Willy Schuep ◽  
Joseph Schierle
Keyword(s):  
Sample Preparation ◽  
Collaborative Study ◽  
The Other ◽  
High Quality ◽  
Carotene Content ◽  
Relative Standard ◽  
Simple Extraction ◽  
Β Carotene ◽  
Significant Underestimation

Abstract Two sample preparation procedures for determination of total β-carotene and (all-)-β-carotene were tested in a collaborative study involving 14 laboratories and using 4 commercial products containing supplemented or natural β-carotene. One assay used classical sample preparation, consisting of saponification, extraction, washing, and drying ofthe extract and redissolution of residue for liquid chromatography (LC). The other assay used simple extraction without saponification. LC conditions were left for the analysts to decide as long as aclear separation of lycopene and ϑ-carotene from Bcarotene was achieved. Mean contents of test samples ranged from 0.3 to 18 mg/100 g for total β-carotene and from 0.2 to 16 mg/100 g for (all-)-β-carotene. Repeatability relative standard deviations (RSDr)for total B-carotene ranged from 2.9 to 5.6% and relative reproducibility standard deviation (RSDR) ranged from 6.5 to 15%. Corresponding values for(all-)-β-carotene were 3.3-5.1 % for RSDr and 8.4- 14% for RSDR. Excluding the (Z)-isomers from uantitation of β-carotene can result in significant underestimation of the effective β-carotene content especially if the LC systems used is high quality.

Determination of Total Dietary Fiber in Foods and Products with Little or No Starch, Nonenzymatic-Gravimetric Method: Collaborative Study

1994 ◽  
Vol 77 (3) ◽  
pp. 687-689 ◽  
Author(s):  
Betty W Li ◽  
Maria S Cardozo
Keyword(s):  
Standard Deviation ◽  
Dietary Fiber ◽  
Fruits And Vegetables ◽  
Simple Procedure ◽  
Collaborative Study ◽  
Gravimetric Method ◽  
Total Dietary Fiber ◽  
Freeze Dried ◽  
Relative Standard

Abstract A collaborative study was conducted to validate a nonenzymatic-gravimetric method for the determination of total dietary fiber (TDF) of samples containing little or no starch such as most fruits, and vegetables and many purified polysaccharides. This simple procedure involves suspension of freeze-dried, ground samples in deionized water and incubation at 37°C for 90 min, followed by pre-cipitation with 4 volumes of 95% ethanol. The weight of the dilute alcohol-insoluble residues after correcting for crude protein and ash corresponds to the TDF content of the sample. Six samples in blind duplicate (apples, apricots, cabbage, carrots, onions, and soy fiber) were sent with Celite to 10 laboratories. The reproducibility relative standard deviation (RSDr) of the TDF values for 9 laboratories ranged from 2.92 to 6.25%. The repeatability standard deviation (RSDr) for the 9 laboratories ranged from 1.50 to 2.70%. The method has been adopted first action by AOAC INTERNATIONAL.

A universal method for the determination of polysorbate 80 in monoclonal antibodies and novel protein therapeutic formulations

2018 ◽  
Vol 10 (11) ◽  
pp. 1296-1304 ◽  
Author(s):  
Veerendra Koppolu ◽  
Bhargavi Vemulapalli ◽  
Jason Thomas ◽  
Sheau-Chiann Wang ◽  
Jon Borman
Keyword(s):  
Monoclonal Antibodies ◽  
Sample Preparation ◽  
Protein Solutions ◽  
Polysorbate 80 ◽  
Universal Method ◽  
Minimal Sample ◽  
Protein Therapeutic ◽  
Novel Protein

A universal and simple assay requiring minimal sample preparation has been developed to quantitate PS80 and other excipients in protein solutions.

scholarly journals Mercury concentration in bivalve molluscs

2015 ◽  
Vol 59 (3) ◽  
pp. 357-360 ◽  
Author(s):  
Józef Szkoda ◽  
Maciej Durkalec ◽  
Agnieszka Nawrocka ◽  
Mirosław Michalski
Keyword(s):  
Total Mercury ◽  
Analytical Procedure ◽  
Absorption Spectrometry ◽  
Dry Weight ◽  
Proficiency Tests ◽  
Bivalve Molluscs ◽  
Quality Assurance Programme ◽  
Freeze Dried ◽  
Wet Weight

AbstractA total of 85 mussel samples of eight species were examined. Analysis of mercury in the freeze-dried samples was carried out by atomic absorption spectrometry method using direct mercury analyser AMA 254. The analytical procedure for determination of mercury was covered by the quality assurance programme of research and participation in national and international proficiency tests. Concentrations of total mercury in all investigated samples were found to be generally low, in the range of 0.033-0.577 mg/kg of dry weight and of 0.003-0.045 mg/kg of wet weight. The results indicate that obtained levels of mercury in bivalve molluscs are not likely to pose a risk to the health of consumers.

Determination of Insoluble and Soluble Dietary Fiber in Foods and Food Products: Collaborative Study

1992 ◽  
Vol 75 (2) ◽  
pp. 360-367 ◽  
Author(s):  
Leon Prosky ◽  
Nils-Georg Asp ◽  
Thomas F Schweizer ◽  
Jonathan W Devries ◽  
Ivan Furda
Keyword(s):  
Dietary Fiber ◽  
Collaborative Study ◽  
Dry Weight ◽  
Food Products ◽  
Soluble Dietary Fiber ◽  
Total Dietary Fiber ◽  
Brussels Sprouts ◽  
Insoluble Dietary Fiber ◽  
Relative Standard

Abstract A collaborative study was conducted to validate a method to determine the Insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) contents of foods and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that for determining total dietary fiber, which was adopted as final action by AOAC and further modified to Include changes in the concentration of buffer and base and substitution of hydrochloric acid for phosphoric acid. Thirty-nine collaborators were each sent 7 test samples In a staggered design for duplicate blind analysis. They were also sent a standard containing 4.3-5.4% IDF and 1.5-2.7% SDF. The 22 foods that were analyzed for IDF and SDF were cabbage, carrots, French beans, kidney beans, butter beans, okra, onions, parsley, chick peas, brussels sprouts, barley, rye flour, turnips, soy bran, wheat germ, raisins, Callmyrna figs, prune powder, Black Mission figs, apple powder, peach powder, and apricot powder. Both IDF and SDF values were calculated as the weight of residue minus the weight of protein and ash reported on a dry weight basis. The reproducibility relative standard deviation (RSDR) of the IDF results ranged from 3.68 to 19.44% for the foods analyzed; almost half the test samples had an RSDR <10%. The RSDR values for the SDF results were somewhat higher. Approximately 50% of the foods analyzed had an RSDR >20%, and 45% had an RSDR between 10 and 20%. An RSDR approaching 45% was calculated for the 2 test samples with the lowest SDF content, 1.35 and 1.90%. Raisins and prune powder had high RSDR values for both SDF and IDF. A major reason for high RSDR values seems to be filtration problems, which are avoidable by analyzing 0.5-0.25 g test samples. The method for the determination of SDF requires further study, but the method for the determination of IDF was adopted first action by AOAC International.

Determination of Arsenic in Vegetable Samples by Hydride Generation Atomic Absorption Spectrometry

1992 ◽  
Vol 75 (6) ◽  
pp. 1029-1031 ◽  
Author(s):  
Miguel Navarro ◽  
Maria C Lopez ◽  
Hermbmia Lopez ◽  
Mercedes Sanchez
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Reference Sample ◽  
Hydride Generation ◽  
Standard Addition ◽  
Absorption Spectrometry ◽  
Dry Weight ◽  
Vegetable Samples ◽  
Relative Standard

Abstract A procedure is described for the determination of arsenic in vegetable samples by hydride generation atomic absorption spectrometry. The samples are mineralized in a microwave acid digestion bomb with nitric acid in the presence of small amounts of vanadium pentoxide. The determination of arsenic is made by the standard addition method. A certified reference sample is analyzed, and the result obtained agreed well with the certified value. The detection limit (dry weight) was about 0.020 μg/g. Reproducibility relative standard deviations ranged from 6.45% at 0.152 μg A μ/g to 8.31 % at 0.059 μg A μ/g. The concentrations of arsenic in vegetable samples ranged from 0.029 to 0.444 μg/g (fresh weight)

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