Determination of Ochratoxin A in Wheat and Maize by Solid Bar Microextraction with Liquid Chromatography and Fluorescence Detection

Abstract

Solid bar microextraction (SBME), followed by liquid chromatography with fluorescence detection (HPLC-FLD), for the quantification of ochratoxin A in wheat and maize was developed. Ground wheat and maize grains were extracted with acetonitrile-water-acetic acid (79:20:1, v/v/v), followed by defatting with cyclohexane, and subjected to SBME-LC-FLD analysis. SBME devices were constructed by packing 2 mg sorbent (C18) into porous polypropylene micro-tubes (2.5 cm length, 600 μm i.d., and 0.2 μm pore size). SBME devices were conditioned with methanol and placed into 5 mL stirred sample solutions for 70 min. After extraction, OTA was desorbed into 200 μL of methanol for 15 min, the solution was removed in vacuum, the residue was dissolved in 50 μL of methanol-water (1:1, v/v) and ochratoxin A content was determined by HPLC-FLD. Under optimized extraction conditions, the limit of detection of 0.9 μg·kg−1 and 2.5 μg·kg−1 and the precision of 3.4% and 5.0% over a concentration range of 1 to 100 μg·kg−1 in wheat and maize flour, respectively, were obtained.

Aflatoxin in Chili Peppers in Nigeria: Extent of Contamination and Control Using Atoxigenic Aspergillus flavus Genotypes as Biocontrol Agents

“…The extracts were cleaned by solid-phase extraction on Puritox columns (R-Biopharm GmbH, Darmstadt, Germany) and solvent was removed in vacuo. The residue was dissolved and derivatized in 100 µL of trifluoroacetic acid for 15 min at RT, diluted 10-times with acetonitrile/water (10:90), and filtered and injected into a reverse-phase HPLC system described previously [48]. Aflatoxins were detected by fluorescence using excitation at 365 nm and emission at 450 nm [49,50,51] and quantified using matrix-matched standards prepared using commercial analytical standards (Sigma-Aldrich GmbH, Steinheim, Germany).…”

ELISA‐type assays of trace biomarkers using microfluidic methods

“…Compared with the above method, Badea et al developed an approach to detect OTA by immobilized anti‐OTA antibody on BSA‐modified gold electrodes, and could detect OTA in the range of 2.5–100 ng/mL . Al‐Hadithi et al detected OTA in wheat and maize with a LOD of 2.5 ng/mL on an HPLC and fluorescence detector system …”

Simultaneous determination of six mycotoxins in peanut by high-performance liquid chromatography with a fluorescence detector

“…Meanwhile, the temperature increase can reduce the stability of substance and increase the volatilisation of organic solution. As the boiling point of CHCl 3 was 61.3 ∘ C, the temperature of water (10,20,25,30,35,40 and 50 ∘ C) was tested in order to choose the appropriate temperature. Figure 5 shows that, by increasing the temperature from 10 to 20 ∘ C, the ER increased obviously, and then the ER remained basically stable.…”

“…AFs [aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2)] have been proved the most potent mutagenic and carcinogenic substances known among mycotoxins, and B1 has been confirmed as a Group‐1 human carcinogen by the International Agency for Research on Cancer (IARC, 1993) because of its highly hepatic carcinogenic . OTA has allegedly been implicated in a range of toxicological effects including nephrotoxicity, neurotoxicity and immunotoxicity in animals and humans, and it has been classified in Group 2B by the IARC . ZEN acts as an endocrine disruptor and interferes with reproductive traits, which cause reproductive problems in farm animals, including infertility, enlargement of uterus and mammary glands, vaginal prolapse and atrophy of testicles .…”