scholarly journals Residual Analysis of Aflatoxins in Spice by HPLC Coupled with Solid-Phase Dispersive Extraction and Solid-Phase Fluorescence Derivatization Method

2020 ◽  
Vol 103 (6) ◽  
pp. 1521-1527
Author(s):  
Koichi Saito ◽  
Junki Ishii ◽  
Misaki Naniwa ◽  
Rie Ishii ◽  
Mihoko Kato ◽  
...  
Keyword(s):  
Solid Phase ◽  
Accurate Method ◽  
Black Pepper ◽  
Mixed Solution ◽  
Z Score ◽  
Method Detection Limit ◽  
Fluorescence Derivatization ◽  
Intermediate Precision ◽  
Triton X ◽  
Micro Analysis

Abstract Background Aflatoxins (AFs) are carcinogenic mycotoxins. A simple, quick, and accurate method for the micro-analysis of AFs in foodstuffs, especially spices, is needed. Objective A sophisticated pretreatment method that combines solid-phase dispersive extraction (SPDE) and solid-phase fluorescence derivatization using immunoaffinity (IA) gel as the solid phase was developed to analyze AFs in spices simply, quickly, and sensitively by liquid chromatography with fluorescence detection. Method White and black pepper samples were extracted with a mixed solution of methanol/water (4:1) and then diluted with 7% aqueous solution of Triton-X. The solution was subjected to cleanup by SPDE using IA gel. Trifluoroacetic acid was added to the IA gel for on-site solid-phase fluorescence derivatization. Results Chromatograms containing well-separated peaks and few interference peaks from contaminants were obtained. The method detection limit of AFs in white and black pepper was 0.15–0.29 ng/g. Repeatability and intermediate precision were <10% and <15%, respectively, and accuracy was 61.7–87.8%. In addition, inter-laboratory precision was <29% and mean recovery was 61.5–76.7%. A favorable z-score of |Z| ≦ 1 was obtained in seven laboratories, although one laboratory gave 2 < |Z| < 3. Conclusions The validity, reliability, practicality, and robustness of the developed method were verified. Highlights By using SPDE and solid-phase fluorescence derivatization in combination for AF analysis, fluorescence derivatization during cleanup was realized, leading to simplification of the pretreatment operation.

IDENTIFICATION OF ODOR COMPONENTS OF AGARWOOD

2015 ◽  
Vol 77 (2) ◽  
Author(s):  
Nor Azah Mohamad Ali ◽  
Nurlaila Ismail ◽  
Mailina Jamil ◽  
Azrina Aziz ◽  
Sahrim Lias ◽  
...  
Keyword(s):  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Chemical Compounds ◽  
Sensor Technology ◽  
Gas Chromatography Mass Spectrometry ◽  
Z Score ◽  
Spme Fiber ◽  
Odor Compounds ◽  
Marker Compounds ◽  
Significant Chemical

This article presents the use of Z-score in assessing the significant chemical compounds extracted by head space solid phase microextraction (HS-SPME) and gas chromatography – mass spectrometry (GC-MS) analysis of an agarwood oil obtained from Melaka, Malaysia. Two types of SPME fiber; polydimethylsiloxane (PDMS) and divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) were used. During the extraction analysis, the results showed that at least 27 and 29 compounds were identified using PDMS and DVB-CAR-PDMS fiber, respectively. DVB-CAR-PDMS fiber was found to be more efficient in terms of selectivity of compounds extraction. The application of Z-score showed that eight and eleven marker compounds were determined in PDMS and DVB-CAR-PDMS fibers, respectively. 4-Phenyl-2-butanone, a-guaiene, β-agarofuran, a-bulnesene, a-agarofuran and 10-epi-g-eudesmol were some of the compounds selected and were often reported significantly in agarwood oils as key odor compounds. The information gathered will be used for compound selection towards grading of agarwood oils by sensor technology.

scholarly journals Molecular Imprinted of Nylon 6 for Selective Separation of Procaine by Solid-Phase Extraction

2021 ◽  
Vol 21 (6) ◽  
pp. 1505
Author(s):  
Muhammed Emad Abood ◽  
Sumayha Muhammed Abbas
Keyword(s):  
Solid Phase Extraction ◽  
Recovery Rate ◽  
Separation Efficiency ◽  
Solid Phase ◽  
Nylon 6 ◽  
Extraction Column ◽  
Phase Extraction ◽  
Mixed Solution ◽  
Imprinted Polymer ◽  
Drug Compound

The study is based on the selective binding ability of the drug compound procaine (PRO) on a surface imprinted with nylon 6 (N6) polymer. Physical characterization of the polymer template was performed by X-ray diffraction and DSC thermal analysis. The imprinted polymer showed a high adsorption capacity to trap procaine (237 µg/g) and excellent recognition ability with an imprinted factor equal to 3.2. The method was applied to an extraction column simulating a solid-phase extraction to separate the drug compound in the presence of tinoxicam and nucleosimide separately and in a mixture of them with a recovery rate more than the presence of tinoxicam and nucleosimide separately and in a mixture of them with a recovery rate of more than 82%. Separation efficiency and excellent selectivity for procaine were ensured using a mixed solution injected into an HPLC technique consisting of a C18 column with a mobile phase mixture of water-acetonitrile (75:25) at pH 3.3. The study of drug control using an imprinted polymer with procaine compound showed that the complete drug release process is faster at pH1 in a maximum period of 80 min. The proposed method was successfully applied on some of the available pharmaceuticals, and it showed high selectivity for the separation of PRO, RE % was < 1.18, and RSD was less than 0.447.

scholarly journals Solid-Phase Extraction and Gas Chromatography with Mass Spectrometric Determination of Capsaicin and Some of Its Analogues from Chili Peppers (Capsicum spp.)

1999 ◽  
Vol 82 (6) ◽  
pp. 1399-1405 ◽  
Author(s):  
Philemon Manirakiza ◽  
Adrian Covaci ◽  
Paul Schepens
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Solid Phase ◽  
Accurate Method ◽  
Mass Spectrometric ◽  
Phase Extraction ◽  
Capsicum Spp ◽  
The Mean ◽  
Chili Peppers

Abstract A rapid and accurate method has been developed for the quantitative determination of capsaicin and its most important analogues, dihydrocapsaicin and nordihydrocapsaicin in chili peppers. These components were extracted with methylene chlo ride and separated from interfering substances with activated charcoal. Further cleanup on Florisil cartridges and elution with ethyl acetate were performed before gas chromatographic with mass spectrometric quantitation. The concentrations found were 440 ± 64 μg/g capsaicin, 81 ± 10 μg/g dihydrocapsaicin, and 11 ± 2 μg/g nordihydrocapsaicin. The mean recovery values for triplicate analysis were between 85-94%.

scholarly journals Initial study of three different pathogenic microorganisms by gas chromatography-mass spectrometry

F1000Research ◽  
2018 ◽  
Vol 6 ◽  
pp. 1415 ◽  
Author(s):  
Najmeh Karami ◽  
Fateme Mirzajani ◽  
Hassan Rezadoost ◽  
Abdollah Karimi ◽  
Fatemeh Fallah ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Respiratory Tract ◽  
Volatile Compounds ◽  
Solid Phase ◽  
Late Phase ◽  
Accurate Method ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Tract Infections

Background: Diagnoses  of  respiratory  tract  infections  usually happen  in  the  late  phase  of  the  disease  and  usually  result  in  reduction  of  the  pathogen  load after broad-spectrum  antibiotic  therapy,  but  not  in eradication of the pathogen.  The  development  of a  non-invasive,  fast,  and  accurate  method  to  detect  pathogens  has  always  been  of  interest  to  researchers  and  clinicians  alike.  Previous studies have shown that bacteria produce organic gases.  The  current  study  aimed  to  identify  the  volatile  organic  compounds  (VOCs)  produced  by three  respiratory  tract  pathogens,  including  Staphylococcus  aureus,  Escherichia  coli  and  Candida  albicans. Methods: The  VOCs  produced  were identified by gas chromatography–mass spectrometry (GC-MS), with  prior  collection  of  microbial  volatile  compounds  using  solid  phase  microextraction  (SPME)  fiber.  The volatile compounds were collected by obtaining bacterial headspace samples. Results: Results  showed  that  these  three  organisms  have  various  VOCs,  which  were  analyzed  under  different  conditions.  By ignoring common VOCs, some species-specific VOCs could be detected.  The most important VOC of E. coli was indole, also some important VOCs produced by S. aureus  were 2,3-pentandione,  cis-dihydro-α-terpinyl  acetate,  1-decyne,  1,3-heptadiene,  2,5-dimethyl  pyrazine,  ethyl  butanoate  and  cyclohexene,4-ethenyl. Furthermore,  most  of the identified  compounds  by  C.  albicans are  alcohols. Conclusions: The  detection  of  VOCs  produced  by  infectious  agents  maybe  the  key  to  make   a  rapid  and  precise  diagnosis  of  infection,  but  more  comprehensive  studies  must  be  conducted  in this  regard.

Determination of Streptomycin Residue in Cucumber and Chinese Cabbage by High-Performance Liquid Chromatography with Postcolumn Derivatization and Fluorometric Detection

2012 ◽  
Vol 95 (2) ◽  
pp. 523-527 ◽  
Author(s):  
Benjing Chen ◽  
Hongyan Zhang ◽  
Baoxiang Lin ◽  
Jing Ge ◽  
Lihong Qiu
Keyword(s):  
Chinese Cabbage ◽  
High Performance ◽  
Accurate Method ◽  
Excitation Wavelength ◽  
Fluorometric Detection ◽  
Mixed Solution ◽  
Fluorescence Detector ◽  
Precision And Accuracy ◽  
Postcolumn Derivatization

Abstract A sensitive and accurate method was developed for the determination of streptomycin using HPLC followed by postcolumn derivatization and fluorometric detection. The analyte was extracted, using aqueous solution from cucumber and Chinese cabbage, by a two-step SPE procedure. The extraction, cleanup, and chromatography conditions were optimized, and the performance of the analysis method was evaluated. The conditions of chromatography were as follows: the separation was performed on a C18 column; the isocratic mobile phase consisted of acetonitrile and a mixed solution containing 10 mM sodium 1,2-naphthoquinone-4-sulfonate and 0.4 mM sodium 1-heptanesulfonate (25 + 75, v/v); and the flow rate was 1 mL/min. The fluorescence detector was set at an excitation wavelength of 263 nm and an emission wavelength of 435 nm. The calibration curve was linear over the range of 50–2000 ng/mL, with a correlation coefficient of 0.9995. The LOD and LOQ were 10 and 30 ng/g, respectively, in both cucumber and Chinese cabbage. The method was validated for selectivity, linearity, precision, and accuracy. The intraday and interday precision and accuracy were within 10%. The mean recoveries from spiked samples were more than 75%, with RSD lower than 10%.

scholarly journals Prevalence of antibodies againstEntamoeba histolyticain Mexico measured by ELISA

1995 ◽  
Vol 115 (3) ◽  
pp. 535-543 ◽  
Author(s):  
C. R. González ◽  
A. Isibasi ◽  
V. Ortiz-Navarrete ◽  
J. Paniagua ◽  
J. A. García ◽  
...  
Keyword(s):  
Entamoeba Histolytica ◽  
Confidence Limit ◽  
Metropolitan Areas ◽  
Solid Phase ◽  
Axenic Culture ◽  
Amoebic Liver Abscess ◽  
Serum Samples ◽  
Indirect Haemagglutination ◽  
Younger Age ◽  
Triton X

SummaryThe prevalence of antibodies againstEntamoeba histolyticawas studied in the Mexican population using an immunoenzyme assay in solid phase (ELISA) and semiautomatic equipment. The antigen was a mixture of membrane proteins obtained by Triton X-100 extraction from an axenic culture ofEntamoeba histolyticaHM1-IMSS. The method was standardized by comparing serum samples from amoebic liver abscess patients with healthy volunteers. From the 60538 samples suppliedbythe National Seroepidemiology Survey, antibodies were found in 4·49 % (4·32–;4·65% at 95 % confidence limit). More significant titres occurred in the central region of the country. The ratio female to male was 1·25:1. The population living in metropolitan areas had probably been infected at a younger age than those living in the country.Important differences were found in the seroprevalence obtained by ELISA compared with a study which used indirect haemagglutination (IHA) in the same sample frame.

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