Immunoaffinity column cleanup with liquid chromatography using post-column bromination for determination of aflatoxins in peanut butter, pistachio paste, fig paste, and paprika powder: collaborative study.

J Stroka; E Anklam; U Jörissen; J Gilbert

PubMed · 10772170

Immunoaffinity column cleanup with liquid chromatography using post-column bromination for determination of aflatoxins in peanut butter, pistachio paste, fig paste, and paprika powder: collaborative study.

Abstract

A collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for the determination of aflatoxin B1 and total aflatoxins at European regulatory limits. The test portion is extracted with methanol-water (8 + 2) for dried figs and paprika, and with methanol-water (8 + 2) plus hexane (or cyclohexane) for peanut butter and pistachios. The sample extract is filtered, diluted with phosphate buffer saline, and applied to an immunoaffinity column. The column is washed with water and the aflatoxins are eluted with methanol. Aflatoxins are quantitated by reversed-phase LC with post-column derivatization (PCD) involving bromination. PCD is achieved with either an electrochemical cell (Kobra cell) and addition of bromide to the mobile phase or pyridinium hydrobromide perbromide. Determination is by fluorescence. Peanut butter, pistachio paste, dried fig paste, and paprika powder samples, both naturally contaminated with aflatoxins and containing added aflatoxins, were sent to 16 collaborators in 16 European countries. Test portions of samples were spiked at levels of 2.4 and 9.6 ng/g for total aflatoxins which included 1.0 and 4.0 ng/g aflatoxin B1, respectively. Recoveries for total aflatoxins ranged from 71 to 92% with corresponding recoveries for aflatoxin B1 of 82 to 109%. Based on results for spiked samples (blind duplicates at 2 levels) as well as naturally contaminated samples (blind duplicates at 4 levels, including blank), the relative standard deviation for repeatability ranged from 4.6 to 23.3% for total aflatoxins and from 3.1 to 20.0% for aflatoxin B1. The relative standard deviation for reproducibility ranged from 14.1 to 34.2% for total aflatoxins, and from 9.1 to 32.2% for aflatoxin B1. The method showed acceptable within-laboratory and between-laboratory precision for all 4 matrixes, as evidenced by HORRAT values <1, at the low levels of determination for both total aflatoxins and aflatoxin B1.

Explore related subjects

Aflatoxin B1 Aflatoxins Arachis Bromine Capsicum Chromatography, Affinity Chromatography, High Pressure Liquid Food Analysis Food Contamination Fruit Immunoassay Indicators and Reagents Nuts Plants, Medicinal Reproducibility of Results Sensitivity and Specificity Comparative Study Journal Article Research Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

J Stroka, E Anklam, U Jörissen, J Gilbert. Immunoaffinity column cleanup with liquid chromatography using post-column bromination for determination of aflatoxins in peanut butter, pistachio paste, fig paste, and paprika powder: collaborative study.. https://pubmed.ncbi.nlm.nih.gov/10772170/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2001

Effect of diallyl sulfide and diallyl disulfide, the active principles of garlic, on the aflatoxin B(1)-induced DNA damage in primary rat hepatocytes.

The objective of this study was to investigate the effect of the active principles in garlic-- diallyl sulfide (DAS) and diallyl disulfide (DADS)--on aflatoxin B(1) (AFB(1))-induced DNA damage in primary rat hepatocytes. Primary rat hepatocytes, induced with DNA damage using 10 microM AFB(1) were used as an experimental model. According to the results of LDH leakage, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS significantly increased the viability of hepatocytes compared with the AFB(1) controls after 4, 8 and 24 h treatment (P<0.05). According to the results of unscheduled DNA synthesis (UDS) test, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS could significantly decrease the DNA damage induced by AFB(1) (P<0.05). Furthermore, 0.5 and 2 mM DAS or 0.5 and 1 mM DADS could increase the glutathione S-transferase (GST) and glutathione peroxidase (GPx) activities as compared with the AFB(1) controls after 24 h treatment (P<0.05). Results of immunoblot analysis of cytosolic GST isoenzyme indicate that the levels of GST isoform Ya, Yb2 and Yc were markedly increased after treatment with 0.5 and 2 mM DAS or 0.5 and 1 mM DADS compared with the AFB(1) control. These results indicate that 0.5 and 2 mM DAS or 0.5 and 1 mM DADS might protect hepatocytes from AFB(1)-induced DNA damage via increasing the activities of GST and GPx.

Aflatoxin B1↗

PubMed2001

Protective role of ascorbic acid to enhance semen quality of rabbits treated with sublethal doses of aflatoxin B(1).

Aflatoxins are toxic to a wide variety of animals, including man. The antioxidant ascorbic acid (AA) plays an important role in various physiological processes in the body including detoxification of different toxic compounds. The objective of this study was to evaluate the effects of AA on productive and reproductive characteristics of mature male rabbits given two sublethal doses (15 or 30 microg/kg of body weight; every other day) of aflatoxin B(1) (AFB(1)). The experiment lasted 18 weeks and included two periods: a treatment period (first 9 weeks) where the animals were given the tested materials, and a recovery period (second 9 weeks) where all the drugs were withdrawn. Results showed that live body weight (LBW), dry matter intake (DMI), relative testes weight (RTW), and serum testosterone were significantly reduced (P<0.05) by treatment with AFB(1) in a dose-dependent manner, and these effects continued during the recovery period. Aflatoxin treatment also decreased (P<0.05) ejaculate volume, sperm concentration, total sperm output, sperm motility index, and semen initial fructose concentration. The negative effects of aflatoxin on semen characteristics were dose-dependent and continued during the recovery period. Treatment with AA increased (P<0.05) LBW, DMI, RTW, serum testosterone concentration, improved semen characteristics, and alleviated the negative effects of AFB(1). Aflatoxin treatment increased (P<0.05) the numbers of abnormal and dead sperms in a dose-dependent manner, and this effect continued during the recovery period. Treatment with AA alleviated the negative effects of AFB1 during treatment and recovery periods. Results demonstrated the beneficial influences of AA in reducing the negative effects of AFB(1) on production and reproduction of male rabbits.

Aflatoxin B1↗

PubMed2001

Integrated plastic microfluidic devices with ESI-MS for drug screening and residue analysis.

For this work, two different plastic microfluidic devices are designed and fabricated for applications in high-throughput residue analysis of food contaminants and drug screening of small-molecule libraries. Microfluidic networks on copolyester and poly(dimethylsiloxane) substrates are fabricated by silicon template imprinting and capillary molding techniques. The first device is developed to perform affinity capture, concentration, and direct identification of targeted compounds using electrospray ionization mass spectrometry. Poly(vinylidene fluoride) membranes sandwiched between the imprinted copolyester microchannels in an integrated platform provide continuous affinity dialysis and concentration of a reaction mixture containing aflatoxin B1 antibody and aflatoxins. The second microfluidic device is composed of microchannels on the poly(dimethylsiloxane) substrates. The device is designed to perform miniaturized ultrafiltration of affinity complexes of phenobarbital antibody and barbiturates, including the sequential loading, washing, and dissociation steps. These microfabricated devices not only significantly reduce dead volume and sample consumption but also increase the detection sensitivity by at least 1-2 orders of magnitude over those reported previously. Improvements in detection sensitivity are attributed to analyte preconcentration during the affinity purification step, limited analyte dilution in the microdialysis junction, minimal sample loss, and the amenability of ESI-MS to nanoscale sample flow rates.

Aflatoxin B1↗