scholarly journals A comparison between enzyme immunoassay and HPLC for ochratoxin A detection in green, roasted and instant coffee

2007 ◽  
Vol 50 (2) ◽  
pp. 349-359 ◽  
Author(s):  
Simone Fujii ◽  
Elisabete Yurie Sataque Ono ◽  
Ricardo Marcelo Reche Ribeiro ◽  
Fernanda Garcia Algarte Assunção ◽  
Cássia Reika Takabayashi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Ochratoxin A ◽  
High Performance ◽  
Screening Tool ◽  
Correlation Coefficients ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa Assay ◽  
Quality And Safety ◽  
Green Coffee ◽  
Instant Coffee

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for ochratoxin A (OTA) detection in green, roasted and instant coffees was developed using anti-OTA monoclonal antibody. Immunological reagents prepared were OTA-BSA (4.76 mg/mL), anti-OTA.7 MAb (2x10³-fold dilution) and HRP-anti IgG (10³-fold dilution). The detection limit was 3.73 ng OTA/g and correlation coefficients (r) between this immunoassay and high performance liquid chromatography were 0.98 for green coffee, 0.98 for roasted and 0.86 for instant. OTA levels detected by ic-ELISA were higher than by HPLC, with ELISA/HPLC ratio of 0.66 - 1.46 (green coffee), 0.96 - 1.11 (roasted) and 0.93 - 1.82 (instant). ELISA recoveries for OTA added to coffee (5 - 70 ng/g) were 81.53 % for green coffee, 46.73 % for roasted and 64.35 % for instant, while recoveries by HPLC were 80.54 %, 45.91 % and 55.15 %, respectively. Matrices interferences were minimized by samples dilution before carrying out the ELISA assay. The results indicate that MAb-based ic-ELISA could be a simple, sensitive and specific screening tool for OTA detection, contributing to quality and safety of coffee products.

Quantification of Ochratoxin A in Swine Kidneys by Enzyme-linked Immunosorbent Assay Using a Simplified Sample Preparation Procedure

1994 ◽  
Vol 57 (11) ◽  
pp. 991-995 ◽  
Author(s):  
J. R. CLARKE ◽  
R. R. MARQUARDT ◽  
A. A. FROHLICH ◽  
R. J. PITURA
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Sample Preparation ◽  
Ochratoxin A ◽  
Immunosorbent Assay ◽  
High Performance ◽  
Correlation Coefficients ◽  
Enzyme Linked Immunosorbent Assay ◽  
Coefficients Of Variation ◽  
High Degree

An improved procedure for sample preparation and quantitation of ochratoxin A (OA) in swine kidneys was developed. Kidney samples were homogenized in acidified ethyl acetate, centrifuged, sub-sampled, dried, reconstituted with methanol and directly assayed using an indirect competitive enzyme-linked immunosorbent assay (ELISA). The rabbit antisera used in the development of this assay was found to have a high degree of cross-reaction with ochratoxins A and C but not with ochratoxins B, α, 4-OH-OA and two structurally similar molecules L-phenylalanine and citrinin with the values being 100, 80, 3.33, 10, 1.4, 0 and 0.04%, respectively. Extraction recoveries as determined by high performance liquid chromatography in kidneys spiked with 0.97 to 15.62 ppb OA were determined. The recovery values ranged from 91 to 110% with acceptable inter-assay coefficients of variation (CV) being obtained at the 3.9 ppb spiking concentration or higher. The lowest reproducible OA detection limit for the ELISA in the spiked swine kidney samples was 7.81 ppb with inter-assay CV of 8.85%. The ELISA analysis of the spiked samples correlated highly with conventional high-performance liquid chromatography (HPLC) analysis but was dependent on the conditions of the assay. Standards prepared in methanol or extract prepared from a kidney had correlation coefficients ® of 0.91 ± 0.09 and 0.94 ± 0.07, respectively. The assay is sensitive, specific, simple and sufficiently accurate for routine analysis of swine kidneys.

D-Dimer Determination to Exclude Pulmonary Embolism: a Two-Step Approach Using Latex Assay as a Screening Tool

1994 ◽  
Vol 72 (01) ◽  
pp. 089-091 ◽  
Author(s):  
P de Moerloose ◽  
Ph Minazio ◽  
G Reber ◽  
A Perrier ◽  
H Bounameaux
Keyword(s):  
Pulmonary Embolism ◽  
Screening Tool ◽  
Screening Tests ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa Assay ◽  
Elisa Technique ◽  
Diagnostic Step ◽  
D Dimer ◽  
Rule Out ◽  
Latex Test

SummaryD-dimer (DD), when measured by a quantitative enzyme-linked immunosorbent assay (ELISA), is a valuable test to exclude venous thromboembolism (VTE). However, DD ELISA technique is not appropriate for emergency use and the available agglutination latex assays are not sensitive enough to be used as an alternative to rule out the diagnosis of VTE. Latex assays could still be used as screening tests. We tested this hypothesis by comparing DD levels measured by ELISA and latex assays in 334 patients suspected of pulmonary embolism. All but one patient with a positive (DD ≥500 ng/ml) latex assay had DD levels higher than 500 ng/ml with the ELISA assay. Accordingly, ELISA technique could be restricted to patients with a negative result in latex assay. This two-step approach would have spared about 50% of ELISA in our cohort. In conclusion, our data indicate that a latex test can be used as a first diagnostic step to rule out pulmonary embolism provided a negative result is confirmed by ELISA and the performance of the latex assay used has been assessed properly.

Polyclonal Antibody-Based ELISA and HPLC Methods for the Determination of Fumonisins in Corn: A Comparative Study

1996 ◽  
Vol 59 (8) ◽  
pp. 893-897 ◽  
Author(s):  
ERIC W. SYDENHAM ◽  
SONJA STOCKENSTRÖM ◽  
PIETER G. THIEL ◽  
JOHN P. RHEEDER ◽  
M. BRUNO DOKO ◽  
...  
Keyword(s):  
Comparative Study ◽  
Polyclonal Antibody ◽  
High Performance ◽  
Linear Regression Analysis ◽  
Correlation Coefficients ◽  
Hplc Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
Regression Slopes ◽  
The Individual ◽  
The Comparative Study

The performance of an experimental polyclonal antibody (PAb)-based competitive direct enzyme-linked immunosorbent assay (CD-ELISA) developed for the analysis of fumonisins in corn was assessed by comparison with an established high-performance liquid chromatography (HPLC) method. The comparative study was conducted using a series of 20 corn samples naturally contaminated with combined fumonisin levels ranging from <0.05 to >5 μg/g (ppm). Linear regression analysis between the results generated by HPLC and CD-ELISA provided correlation coefficients (r) and regression slopes (b) of r = 0.960, b = 1.493 (P < 0.001); r = 0.865, b = 3.903 (P < 0.001); and r = 0.832, b = 0.107 (P < 0.001) for the individual fumonisins B1 (FB1), B2 (FB2) and B3 (FB3), respectively, while corresponding values of r = 0.967, b = 1.059 (P < 0.001) were obtained for the combined FB1, FB2, and FB3 concentrations. In 3 of 18 fumonisin-positive corn samples, combined fumonisin levels determined by CD-ELISA were between 85 and 100% higher than those determined in the same extracts by HPLC, while in 13 other samples, CD-ELISA results were between 1.8 and 53% higher than those determined by HPLC. Conversely, in 2 of 18 samples, CD-ELISA results were lower than those determined by HPLC. The differences recorded between HPLC and the experimental PAb-based CD-ELISA were far less than those previously recorded for other mono- and polyclonal antibody-based CD-ELISA systems. The results indicate that the experimental PAb-based CD-ELISA may be effectively applied for the initial screening for fumonisins in corn.

Ochratoxins A and B, Xanthomegnin, Viomellein and Vioxanthin Production by Isolates of Aspergillus ochraceus from Green Coffee Beans

1983 ◽  
Vol 46 (11) ◽  
pp. 965-968 ◽  
Author(s):  
MICHAEL E. STACK ◽  
PHILIP B. MISLIVEC ◽  
TURGUT DENIZEL ◽  
REGINA GIBSON ◽  
ALBERT E. POHLAND
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Ochratoxin A ◽  
High Performance ◽  
Toxin Production ◽  
Aspergillus Ochraceus ◽  
Average Level ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans

Isolates from Aspergillus ochraceus obtained from green coffee beans were cultured on rice and water. After 20 d of growth the cultures were extracted with chloroform and the extracts were analyzed by high performance liquid chromatography for ochratoxin A (OA), ochratoxin B (OB), xanthomegnin (X), viomellein (V) and vioxanthin (VX). Forty-three percent of the isolates produced OA at an average level of 397 μg of toxin/g rice, 17% produced OB at an average level of 312 μg/g, and 84% produced X, V, and VX at an average level of 281, 417 and 386 μg/g, respectively. The highest levels of toxin production were OA, 2088 μg/g; OB, 3375 μg/g; X, 1562 μg/g; V, 2514 μg/g; and VX, 2054 μg/g. VX has not previously been reported as an A. ochraceus metabolite.

A Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay for Determination of Homoharringtonine

Planta Medica ◽  
2018 ◽  
Vol 84 (14) ◽  
pp. 1038-1044 ◽  
Author(s):  
Benyakan Pongkitwitoon ◽  
Seiichi Sakamoto ◽  
Rika Nagamitsu ◽  
Waraporn Putalun ◽  
Hiroyuki Tanaka ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Immunosorbent Assay ◽  
Myeloid Leukemia ◽  
High Performance ◽  
Sodium Periodate ◽  
Limit Of Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Study Support ◽  
Mediated Oxidation

AbstractHomoharringtonine (HHT), also known as omacetaxine, is a natural compound found in the genus Cephalotaxus and is a promising pharmaceutical drug used for the treatment of chronic or accelerated phase chronic myeloid leukemia. As a tool for the quantitative determination of HHT, a specific monoclonal antibody against HHT (MAb 6A1) was generated by conjugates prepared via sodium periodate-mediated oxidation. The developed indirect competitive enzyme-linked immunosorbent assay (icELISA) using MAb 6A1 was found to be highly specific and sensitive with a limit of detection for HHT of 48.8 ng/mL. Validation assays to evaluate precision and accuracy of the method were conducted by the use of intra- and inter-assay analysis, recovery test, and comparison analysis between the amounts of HHT determined by ELISA and high-performance liquid chromatography. These results revealed that the established icELISA using MAb 6A1 is specific, sensitive, and reliable enough to be applied to the qualitative analysis for HHT. Furthermore, the results of this study support the usefulness of sodium periodate as a reagent for the conjugation between Cephalotaxus alkaloids and proteins for producing specific antibodies.

Comparative Detection of Fumonisin by HPLC, ELISA, and Immunocytochemical Localization in Fusarium Cultures

1995 ◽  
Vol 58 (6) ◽  
pp. 666-672 ◽  
Author(s):  
MARIA VICTORIA TEJADA-SIMON ◽  
LILIAN T. MAROVATSANGA ◽  
JAMES J. PESTKA
Keyword(s):  
Monoclonal Antibody ◽  
Fusarium Moniliforme ◽  
High Performance ◽  
Time Course ◽  
Fumonisin B1 ◽  
Fusarium Proliferatum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunocytochemical Localization ◽  
Large Deposits

Fumonisins are a group of mycotoxins that are elaborated by Fusarium moniliforme and Fusarium proliferatum and that have recently been associated with animal and human disease. In this study, the time course of fumonisin B1 (FB1) production in corn was monitored in five Fusarium cultures using high-performance liquid chromatography (HPLC), enzyme-linked immunosorbent assay (ELISA), and in situ localization by an enzyme-linked immunocytochemical technique (ELICT). Using HPLC on culture extracts prepared with 50% (vol/vol) acetonitrile in water, FB1 was detectable at 3 days with maximal FB1 (ranging from 230 to 3,000 ppm) occurring between 14 and 28 days. Although there was a positive correlation between FB1 detected by HPLC and ELISA, the latter consistently yielded higher results than HPLC. Maximal FB1 “equivalents” detected by ELISA ranged from 12,000 to 35,000 ppm. Following fixation of Fusarium from cultures, ELICT revealed the presence of large deposits indicative of fumonisin or fumonisin-like cross-reacting compounds in mycelia, microconidia, and microconidia. Prior to fixation, these compounds were extractable in 50% (vol/vol) acetonitrile in water. ELICT results qualitatively correlated with HPLC and ELISA over the time course of the cultures. Taken together, the results suggest that (a) ELISA or ELICT could be used for qualitative screening of FB1-producing cultures, and (b) in addition to FB1, the monoclonal antibody-based ELISA detected one or more compounds that structurally resemble FB1 and occur concurrently with FB1.

scholarly journals Multiple Mycotoxins in Kenyan Rice

Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 203
Author(s):  
Samuel K. Mutiga ◽  
J. Musembi Mutuku ◽  
Vincent Koskei ◽  
James Kamau Gitau ◽  
Fredrick Ng’ang’a ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
High Performance ◽  
Low Frequency ◽  
Rice Cultivar ◽  
Enzyme Linked Immunosorbent Assay ◽  
Milled Rice ◽  
Regulatory Limits ◽  
Liquid Chromatography Tandem Mass ◽  
Rice Samples ◽  
Time Of Harvest

Multiple mycotoxins were tested in milled rice samples (n = 200) from traders at different milling points within the Mwea Irrigation Scheme in Kenya. Traders provided the names of the cultivar, village where paddy was cultivated, sampling locality, miller, and month of paddy harvest between 2018 and 2019. Aflatoxin, citrinin, fumonisin, ochratoxin A, diacetoxyscirpenol, T2, HT2, and sterigmatocystin were analyzed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS). Deoxynivalenol was tested using enzyme-linked immunosorbent assay (ELISA). Mycotoxins occurred in ranges and frequencies in the following order: sterigmatocystin (0–7 ppb; 74.5%), aflatoxin (0–993 ppb; 55.5%), citrinin (0–9 ppb; 55.5%), ochratoxin A (0–110 ppb; 30%), fumonisin (0–76 ppb; 26%), diacetoxyscirpenol (0–24 ppb; 20.5%), and combined HT2 + T2 (0–62 ppb; 14.5%), and deoxynivalenol was detected in only one sample at 510 ppb. Overall, low amounts of toxins were observed in rice with a low frequency of samples above the regulatory limits for aflatoxin, 13.5%; ochratoxin A, 6%; and HT2 + T2, 0.5%. The maximum co-contamination was for 3.5% samples with six toxins in different combinations. The rice cultivar, paddy environment, time of harvest, and millers influenced the occurrence of different mycotoxins. There is a need to establish integrated approaches for the mitigation of mycotoxin accumulation in the Kenyan rice.

scholarly journals Standardization of an analytical method to quantify ochratoxin A in green coffee beans by high performance liquid chromatography

2020 ◽  
Vol 9 (8) ◽  
pp. e39985070
Author(s):  
Wilder Douglas Santiago ◽  
Alexandre Rezende Teixeira ◽  
Juliana de Andrade Santiago ◽  
Ana Cláudia Alencar Lopes ◽  
Rafaela Magalhães Brandão ◽  
...  
Keyword(s):  
Food Safety ◽  
Ochratoxin A ◽  
High Performance ◽  
Animal Health ◽  
Green Coffee ◽  
Fungal Contamination ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Green Coffee Beans ◽  
Coffee Beans

Nowadays, Brazil is the largest producer and exporter of coffee, also the second largest consumer of the beverage. The importance of ensuring food safety for consumers has influenced research to improve and monitor the final product quality. Coffee is a product that presents a high risk of fungal contamination, which can result in the presence of mycotoxins and poses risks to human and animal health. Therefore, this study aimed to standardize a chromatographic method to test and quantify ochratoxin A in 13 samples of green coffee beans. The green coffee beans were stored in sheds without temperature or humidity control. Samples were ground, and the analyte was extracted by a 3% methanol:sodium bicarbonate (1:2 v/v) solution. Ochratoxin A was quantified in a high performance liquid chromatograph. The method was validated by testing the selectivity, linearity, accuracy, limits of detection and quantification. The method presented robustness to the tested parameters and among the analyzed samples. Ochratoxin A was detected above the limit established by the legislation (75.19 µg kg-1) only in one sample. Overall, the storage of green coffee beans in these sheds was adequate, since 12 samples had a low content of ochratoxin A and they were within the limit established by legislation. Therefore, food safety was guaranteed without any severe mycotoxin contamination.

scholarly journals Simultaneous Quantitative Assessment of Ochratoxin A, Patulin, 5-Hydroxymethylfurfural, and Bisphenol A in Fruit Drinks Using HPLC with Diode Array-Fluorimetric Detection

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1633
Author(s):  
Norfarizah Hanim Hassan ◽  
Haneen Ibrahim Ahmad Al Othman ◽  
Nur Rabiatutadawiah Abdul Malek ◽  
Musfirah Zulkurnain ◽  
Bahruddin Saad ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Ochratoxin A ◽  
High Performance ◽  
Correlation Coefficients ◽  
Sample Pretreatment ◽  
Cost Effective ◽  
Diode Array ◽  
Gradient System ◽  
Relative Standard ◽  
In Series

The analysis of regulated contaminants in fruit drinks often requires suitable validated and rapid analytical methods for cost-effective food control, and is of considerable interest among the fruit beverage industry. This study demonstrated a rapid and sensitive high-performance liquid chromatography approach for the simultaneous determination of ochratoxin A (OTA), patulin (PAT), 5-hydroxymethylfurfural (HMF), and bisphenol A (BPA) in various fruit drinks. The separations were achieved using a C18 core-shell column with both photo-diode array and fluorimetric detections connected in series. A gradient system consisting of methanol and 0.1% formic acid at a flow rate of 1.2 mL min−1, thermostated at 35 °C, provided fast elution with run time <9 min. Sample pretreatment was optimised to enable extraction of all analytes from fruit drink matrices. The optimised method was validated. Correlation coefficients of R > 0.99 were achieved with detection limits of 0.5 ng mL−1 (OTA), 1.1 ng mL−1 (PAT), 7.9 ng mL−1 (HMF), and 1.0 ng mL−1 (BPA). Recoveries ranged from 82% to 99%. Good relative standard deviations for intraday retention times (≤3.54%) and peak area (≤3.5%) were achieved. The developed multi-contaminants analysis method was successfully applied to determine OTA, PAT, HMF, and BPA in various fruit drinks.

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