scholarly journals SLE Single-Step Purification and HPLC Isolation Method for Sterols and Triterpenic Dialcohols Analysis from Olive Oil

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2019
Author(s):  
Manuel León-Camacho ◽  
María del Carmen Pérez-Camino
Keyword(s):  
High Performance ◽  
Small Sample Size ◽  
Reference Value ◽  
Fats And Oils ◽  
Single Step ◽  
Small Sample ◽  
Analytical Control ◽  
Unsaponifiable Fraction ◽  
Time Saving ◽  
Relative Standard

The unsaponifiable fraction of oils and fats constitutes a very small fraction but it is an essential part of the healthy properties of some specific oils. It is a complex fraction formed by a large number of minor compounds and it is a source of information to characterize and authenticate the oil sample. Specially, the composition of sterols of any oil or fat is a distinctive feature of itself and, therefore, it has become a useful tool for detecting contaminants and adulterants in oils. A new supported liquid extraction (SLE) technique for the analysis and characterization of the unsaponifiable fraction of fats and oils is proposed. The SLE system includes, as a stationary phase, a combination of adsorbent materials which allow a highly purified unsaponifiable matter ready to be isolated by high performance liquid chromatography (HPLC) and quantified by gas chromatography (GC). This method ensures the removal of fatty acids, avoiding possible interferences and making the analysis of sterols and triterpenic dialcohols easier. The procedure uses a small sample size (0.2 g), reduces the volume of solvents and reagents, and reduces the handling of samples subjected to analytical control. All this is achieved without losing either precision—a relative standard deviation of each compound lower than the reference value (≤16.4%)—or recovery, being for all compounds higher than 88.00%. Therefore, this new technique represents a significant economic and time saving in business control laboratories, a larger productivity and enhancement of working safety.

High-Performance Liquid Chromatography Determination of Acrylamide after Its Extraction from Potato Chips

2019 ◽  
Vol 25 (4) ◽  
pp. 338-344
Author(s):  
Maryam Ghalebi ◽  
Samin Hamidi ◽  
Mahboob Nemati
Keyword(s):  
Organic Solvent ◽  
Organic Phase ◽  
High Performance ◽  
Single Step ◽  
Potato Chips ◽  
Process Efficiency ◽  
Local Market ◽  
Good Precision ◽  
Time Saving ◽  
Relative Standard

Background: Acrylamide is a known carcinogenic product that has been found among the substances such as potato chips which to be processed under the heat-treatment. In order to extract amounts of acrylamide from fried chips in market, an ultrasound-assisted liquid– liquid extraction (UA-LLE) technique is proposed. The UA-LLE coupled LLE and ultrasonication in a single step. Methods: Chips samples were dissolved in an extracting organic solvent using ultrasonication to prompt transferring of acrylamide into the organic phase. As a result, the extraction time and process efficiency were significantly enhanced through increasing the collision power and mass transfer between grounded chips and organic phase. Results: Important parameters affecting the extraction efficiency such as kind of organic solvent and its volume, re-dissolving solvent and pH were optimized. This newly proposed method has been applied to determine the trace acrylamide in potato chips samples purchased from local market. Conclusion: UA-LLE is a handy, economic and time-saving method, with high extraction yield (over 103% average recovery) and good precision (lower than 15% relative standard deviation, RSD). Most importantly, it seems this method to be an ideal pre-treatment method for the extraction of acrylamide in food matrix in food quality control laboratories.

scholarly journals Simple and rapid liquid chromatography method for simultaneous determination of isoniazid and pyrazinamide in plasma

2012 ◽  
Vol 9 (1) ◽  
pp. 13-18 ◽  
Author(s):  
AK Kumar Hemanth ◽  
V Sudha ◽  
G Ramachandran
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
Small Sample Size ◽  
Accurate Method ◽  
Reversed Phase ◽  
Small Sample ◽  
Pharmacokinetic Studies ◽  
Chromatography Method ◽  
Relative Standard

Introduction: Treatment of tuberculosis (TB) requires a combination of drugs. Isoniazid (INH) and pyrazinamide (PZA) are key components of the fi rst-line regimen used in the treatment of TB and monitoring these drug levels in plasma would help in better patient care. The objective of the study is to develop and validate a simple and rapid high performance liquid chromatographic method for simultaneous determination of INH and PZA in human plasma. Methodology: The method involved deproteinisation of plasma with para hydroxy benzaldehyde and trifl uoroacetic acid and analysis using a reversed-phase C8 column and UV detection at 267nm. The fl ow rate was set at 1.5 ml/min at ambient temperature. The accuracy, linearity, precision, specifi city, stability and recovery of the method were evaluated. The method was applied to estimate plasma INH and PZA collected from six children with TB. Results: Well resolved peaks of PZA and INH at retention times of 3.2 and 6.1 minutes respectively were obtained. The assay was linear from 0.25 - 10.0 ìg/ml for INH and 1.25 – 50.0 ìg/ml for PZA. The within-day and between-day relative standard deviation for standards were below 10%. The average recoveries of INH and PZA from plasma were 104 and 102% respectively. Conclusions: A rapid and accurate method for simultaneous determination of INH and PZA in plasma was validated. The assay spans the concentration range of clinical interest. The easy sample preparation and small sample size makes this assay highly suitable for pharmacokinetic studies of INH and PZA in TB patients. SAARC Journal of Tuberculosis, Lung Diseases & HIV/AIDS 2012; IX (1) 13-18 DOI: http://dx.doi.org/10.3126/saarctb.v9i1.6960

Kernel Null Space Marginal Fisher Analysis for Face Recognition

2014 ◽  
Vol 889-890 ◽  
pp. 1065-1068
Author(s):  
Yu’e Lin ◽  
Xing Zhu Liang ◽  
Hua Ping Zhou
Keyword(s):  
Feature Extraction ◽  
Face Recognition ◽  
Sample Size ◽  
High Performance ◽  
Null Space ◽  
Small Sample Size ◽  
Recognition Rate ◽  
Original Data ◽  
Small Sample ◽  
Neighborhood Structure

In the recent years, the feature extraction algorithms based on manifold learning, which attempt to project the original data into a lower dimensional feature space by preserving the local neighborhood structure, have drawn much attention. Among them, the Marginal Fisher Analysis (MFA) achieved high performance for face recognition. However, MFA suffers from the small sample size problems and is still a linear technique. This paper develops a new nonlinear feature extraction algorithm, called Kernel Null Space Marginal Fisher Analysis (KNSMFA). KNSMFA based on a new optimization criterion is presented, which means that all the discriminant vectors can be calculated in the null space of the within-class scatter. KNSMFA not only exploits the nonlinear features but also overcomes the small sample size problems. Experimental results on ORL database indicate that the proposed method achieves higher recognition rate than the MFA method and some existing kernel feature extraction algorithms.

Work-life balance and male lawyers: a socially constructed and dynamic process

2019 ◽  
Vol 48 (4) ◽  
pp. 866-879
Author(s):  
Galina Boiarintseva ◽  
Julia Richardson
Keyword(s):  
High Performance ◽  
Small Sample Size ◽  
Small Sample ◽  
Work Life ◽  
Work Life Balance ◽  
Life Balance ◽  
Content Type ◽  
Socially Constructed ◽  
Male Dominated ◽  
Societal Expectations

PurposeThe purpose of this paper is to theorize men’s experiences of work-life balance in male-dominated, high-performance industries.Design/methodology/approachThis study provides an in-depth qualitative study comprising interviews and informal conversations with male lawyers in Canada.FindingsThis study highlights the socially constructed nature of male lawyers’ experiences of work-life balance and the recursive impact of industry, professional and societal expectations and norms.Research limitations/implicationsA relatively small sample size, suggesting the need for further study with a larger and more diverse sample. The study was conducted in Canada – other national contexts may furnish different results.Practical implicationsThis study identifies the need for greater awareness of how institutional, professional and societal expectations and norms impact on men’s experiences of work-life balance in male-dominated, high-performance industries.Social implicationsThis paper indicates that greater attention needs to be paid to work-life balance among men in male-dominated, high-performance industries.Originality/valueThis paper explores men’s experiences of work-life balance in a male-dominated industry within an interpretivist paradigm.

scholarly journals A Study on the Sloshing Problem of Vertical Storage Tanks under the Action of Near-Fault Earthquakes

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Lijian Zhou ◽  
Tian Xu ◽  
Zhaohong Lu ◽  
Dong Zhang
Keyword(s):  
Wave Height ◽  
Storage Tank ◽  
Small Sample Size ◽  
Ground Motions ◽  
Reference Value ◽  
Small Sample ◽  
Storage Tanks ◽  
Near Fault ◽  
Practical Engineering ◽  
Near Fault Earthquakes

In this study, through a vibration table test, finite element simulation, and research on the rationality of the wave-height fortification of national storage tank specifications, the sloshing response of vertical storage tanks under the action of near-fault ground motion was analyzed. The test results showed that the sloshing wave height of a vertical storage tank was larger under near-fault or long-period ground motions, and the relationship between the sloshing wave height and the peak acceleration of input ground motions was approximately linear. The numerical simulations of the model tank showed that the simulation wave height and the test wave-height data were well fitted. Therefore, it was feasible to simulate the sloshing of large vertical storage tanks using ADINA software. In addition, a large number of sloshing simulations of near-fault ground motions on 10,000 m3 vertical storage tanks were performed. The simulated wave height had a high correlation with the predominant period or pulse period of near-fault ground motions. Under the calculation with similar parameters, the wave height of the tank standard in several countries had a lower fortification of the near-fault excitation wave height. Through the root mean-square method using a small sample size, a wave-height correction under a near-fault effect was applied to the wave-height formula for the Chinese tank seismic specification. Finally, the problem of a double-damping correction was addressed by adjusting China’s GB50341 wave-height formula. This work provides a reference value for practical engineering applications.

scholarly journals THE VARIATION OF INTRAOCULAR PRESSURE IN THE CONTEXT OF ABDOMINAL SURGERY

2020 ◽  
Vol 7 (2) ◽  
pp. 52-57
Author(s):  
Roxana Gabriela Chiș ◽  
Florentina Mușat ◽  
Georgiana Radu ◽  
O. Andronic ◽  
D. Ion ◽  
...  
Keyword(s):  
Laparoscopic Cholecystectomy ◽  
Intraocular Pressure ◽  
Abdominal Surgery ◽  
High Performance ◽  
Small Sample Size ◽  
Open Cholecystectomy ◽  
Small Sample ◽  
Abdominal Pressure ◽  
The University ◽  
Observational Descriptive Study

The human body can be envisioned as a high-performance machine that operates on the principle of "gears". As a consequence, any disorder at a certain level might lead to imbalances in other areas, which are sometimes difficult to detect and measure. One such relationship between two seemingly unrelated systems is that of abdominal surgery and intraocular pressure. The literature on this subject is poor, but available research suggests the occurrence of a change in intraocular pressure in the context of abdominal surgery. The present study analyzed the variation of intraocular pressure for two groups of patients who underwent classical or laparoscopic cholecystectomy. The present research is based on a prospective, non-interventional, observational, descriptive study, carried out in the IIIrd General Surgery Clinic of the University Emergency Hospital, Bucharest. The study included patients who underwent abdominal surgery during January 2018 - December 2019. The study gathered a total of 67 patients, separated into two groups: 52 patients who underwent laparoscopic cholecystectomy and 15 who underwent open cholecystectomy. No definite relationship between intra-abdominal pressure and intraocular pressure was found in the analyzed group, probably due to the small sample size, but further research is encouraged.

The HBG2 rs7482144 (C > T) Polymorphism is Linked to HbF Levels but not to the Severity of Sickle Cell Anemia

2021 ◽  
Author(s):  
Bhaskar V. K. S. Lakkakula ◽  
Smaranika Pattnaik
Keyword(s):  
Disease Severity ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
High Performance ◽  
Complete Blood Count ◽  
Small Sample Size ◽  
Severe Disease ◽  
Small Sample ◽  
Total Leucocyte Count ◽  
Severity Scores

AbstractSickle cell anemia (SCA) is a severe disease characterized by anemia, acute clinical complications, and a relatively short life span. In this disease, abnormal hemoglobin makes the red blood cells deformed, rigid, and sticky. Fetal hemoglobin (HbF) is one of the key modulators of SCA morbidity and mortality. Interindividual HbF variation is a heritable trait that is controlled by polymorphism in genes linked and unlinked to the hemoglobin β gene (HBB). The genetic polymorphisms that determine HbF levels are known to ameliorate acute clinical events. About 190 well-characterized homozygous SCA patients were included in this study. Complete blood count (CBC), high-performance liquid chromatography (HPLC), and clinical investigations were obtained from patient's records. Severity scores were determined by using the combination of anemia, complications, total leucocyte count, and transfusion scores. HBG2 rs7482144 polymorphism was genotyped by using the polymerase chain reaction and restriction fragment length polymorphism. The association between HBG2 rs7482144 polymorphism and HbF levels as well as the disease severity of SCA were assessed. SCA patients carrying TT genotype were found to have higher HbF levels. In addition, SCA patients with increased severity showed significantly lower levels of hemoglobin, HbF, and hematocrit values. However, the genotypes of HBG2 rs7482144 polymorphism were not found to be associated with the risk of disease severity. In summary, this study demonstrated that HBG2 rs7482144 polymorphism is linked with HbF levels, but it does not affect disease severity. The sample sizes used and the pattern of association deduced from our small sample size prevents us from extrapolating our findings further.

scholarly journals Analysis of Flavonol Aglycones and Terpenelactones in Ginkgo biloba Extract: A Comparison of High-Performance Thin-Layer Chromatography and Column High-Performance Liquid Chromatography

2007 ◽  
Vol 90 (5) ◽  
pp. 1203-1209 ◽  
Author(s):  
Dean E Gray ◽  
Dale Messer ◽  
Andrew Porter ◽  
Brian Hefner ◽  
Dama Logan ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Ginkgo Biloba ◽  
High Performance ◽  
Flavonol Glycosides ◽  
Time Saving ◽  
Relative Standard ◽  
Layer Chromatography

Abstract Advancements in automated high-performance thin-layer chromatography (HPTLC) have made it feasible to assess its use for the quantitative analysis of marker compounds in botanical preparations. We report here the findings of method comparisons for the terpenelactones and flavonol aglycones by column high-performance liquid chromatography (HPLC) with evaporative light scattering and UV detection, and HPTLC with a scanning densitometer. For the HPTLC assay of terpenelactones, total bilobalide, ginkgolide A, and ginkgolide B consistently achieved <70 of the total determined using HPLC, regardless of variations to postchromatographic derivatization time and temperature. Accuracy testing showed the possibility of a matrix interference. In contrast, a good relationship (95) was determined between HPTLC and HPLC for determination of total flavonol glycosides (calculated from combined quercetin, kaempferol, and isorhamnetin) from an acid-hydrolyzed Ginkgo biloba L. (GBE) sample. The HPTLC flavonol aglycone method also performed well in terms of accuracy (overall average of 96 recovery for the 3 aglycones) and consecutive plate repeatability (overall percent relative standard deviation of 4.4). It is demonstrated that HPTLC can be a time-saving complement to HPLC for routine analysis of the flavonol glycosides in GBE.

Determination of Organic Impurities in Anthraquinone Color Additives D&C Violet No. 2 and D&C Green No. 6 by Ultra-High Performance Liquid Chromatography

2017 ◽  
Vol 100 (1) ◽  
pp. 230-235 ◽  
Author(s):  
H H Wendy Yang
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Correlation Coefficients ◽  
Photodiode Array Detection ◽  
Time Saving ◽  
Organic Impurities ◽  
Relative Standard ◽  
Photodiode Array ◽  
Color Additive

Abstract A new practical and time-saving ultra-high performance liquid chromatography (UHPLC) method has been developed for determining the organic impurities in the anthraquinone color additives D&C Violet No. 2 and D&C Green No. 6. The impurities determined are p-toluidine, 1-hydroxyanthraquinone, 1,4-dihydroxyanthraquinone, and two subsidiary colors. The newly developed UHPLC method uses a 1.7-μ particle size C-18 column, 0.1 M ammonium acetate and acetonitrile aseluents, and photodiode array detection. For the quantification of the impurities, six-point calibration curves were used with correlation coefficients that ranged from 0.9974 to 0.9998. Recoveries of impurities ranged from 99 to 104%. Relative standard deviations ranged from 0.81 to 4.29%. The limits of detection for the impurities ranged from 0.0067% to0.216%. Samples from sixteen batches of each color additive were analyzed, and the results favorably compared with the results obtained by gravity-elution column chromatography, thin-layer chromatography, and isooctane extraction. Unlike with those other methods, use of the UHPLC method permits all of the impurities to be determined in a single analysis, while also reducing the amount of organic waste and saving timeand labor. The method is expected to be implemented by the U.S. Food and Drug Administration for analysis of color additive samples submitted for batch certification.

scholarly journals Determination of Tranquilizers in Swine Urine by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3215 ◽  
Author(s):  
Yingyu Wang ◽  
Xiaowei Li ◽  
Yuebin Ke ◽  
Chengfei Wang ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Single Step ◽  
Swine Urine ◽  
Relative Standard ◽  
Positive Mode

A rapid, reliable, and sensitive method was developed for the determination of ten tranquilizers in swine urine. Sample preparation was based on solid-phase extraction, which combined isolation of the compounds and sample cleanup in a single step. Separation was performed on a reversed phase C18 column by gradient elution with a chromatographic run time of seven minutes, consisting of 0.1% formic acid in water and acetonitrile as the mobile phase. Multiple reaction monitoring in positive mode was applied for data acquisition. Matrix-matched calibration was used for quantification and good linearity was obtained with coefficients of determination higher than 0.99. The average recoveries of fortified samples at concentrations between 0.05 and 10 µg/L ranged from 85% to 106% with interday relative standard deviations of less than 13% in all cases. The limits of detection and limits of quantification obtained for tranquilizers in the urine were in the ranges of 0.03–0.1 µg/L and 0.05–0.25 µg/L, respectively. The applicability of the proposed method was demonstrated by analyzing real samples; diazepam was detected at concentrations between 0.3 and 0.6 μg/L.

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