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Two-dimensional heart-cut LC-LC improves accuracy of exact-matching double isotope dilution mass spectrometry measurements of aflatoxin B1 in cereal-based baby food, maize, and maize-based feed.

Breidbach A, Ulberth F - Anal Bioanal Chem (2015)

Bottom Line: This is evidenced by the expanded measurement uncertainty (k=2) of 0.017 μg/kg or 8.9 % relative to a mass fraction of aflatoxin B1 in a cereal-based baby food of 0.197 μg/kg.This value is in perfect agreement with the consensus value of this material from a proficiency test (PT) scheme for National Reference Laboratories executed by the European Reference Laboratory for Mycotoxins.The effort necessary to perform the described methodology precludes its frequent use but for specific applications we see it as a valuable tool.

View Article: PubMed Central - PubMed

Affiliation: European Commission, Joint Research Center, Institute for Reference Materials and Measurements, 2440 Geel, Belgium. andreas.breidbach@ec.europa.eu

ABSTRACT
Aflatoxins, mycotoxins of fungi of the Aspergillus sp., pose a risk to consumer health and are, therefore, regulated by more than 100 countries. To facilitate method development and validation as well as assessment of measurement capabilities, availability of certified reference materials and proficiency testing schemes is important. For these purposes, highly accurate determinations of the aflatoxin content in the materials used are necessary. We describe here the use of two-dimensional heart-cut LC-LC in combination with exact-matching double isotope dilution mass spectrometry to determine the content of aflatoxin B1 in three materials used in a proficiency testing scheme. The serious reduction in ionization suppression afforded by the two-dimensional heart-cut LC-LC had a positive effect on the precision of the measured isotope ratios of the exact-matching double isotope dilution mass spectrometry. This is evidenced by the expanded measurement uncertainty (k=2) of 0.017 μg/kg or 8.9 % relative to a mass fraction of aflatoxin B1 in a cereal-based baby food of 0.197 μg/kg. This value is in perfect agreement with the consensus value of this material from a proficiency test (PT) scheme for National Reference Laboratories executed by the European Reference Laboratory for Mycotoxins. The effort necessary to perform the described methodology precludes its frequent use but for specific applications we see it as a valuable tool.

No MeSH data available.


Related in: MedlinePlus

Box and Whisker plots of spike ion peak areas normalized to area per μL injection volume for the feed material spiked volumetrically before extraction (a) and the same native material spiked after extraction (b); each set represent three repeated injections
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Fig2: Box and Whisker plots of spike ion peak areas normalized to area per μL injection volume for the feed material spiked volumetrically before extraction (a) and the same native material spiked after extraction (b); each set represent three repeated injections

Mentions: The improved chromatographic resolution resulted in significantly less ion suppression (Fig. 2). To restore comparability between the 20 μL injection volume for LC-LC and the 5 μL for LC, peak areas were normalized to area per μL injection volume. The left panel (a) shows the normalized peak areas of the spike ion in the feed material spiked volumetrically once before extraction, the right one (b) shows the same for the feed material spiked after extraction. Both plots show the severe suppression of the signal in 1D-LC. The fact that the LC-LC peak area for the “spike before extraction” is slightly smaller than for the spike added to the crude extract indicates that the extraction efficiency is not 100 % but still acceptable.Fig. 2


Two-dimensional heart-cut LC-LC improves accuracy of exact-matching double isotope dilution mass spectrometry measurements of aflatoxin B1 in cereal-based baby food, maize, and maize-based feed.

Breidbach A, Ulberth F - Anal Bioanal Chem (2015)

Box and Whisker plots of spike ion peak areas normalized to area per μL injection volume for the feed material spiked volumetrically before extraction (a) and the same native material spiked after extraction (b); each set represent three repeated injections
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4383822&req=5

Fig2: Box and Whisker plots of spike ion peak areas normalized to area per μL injection volume for the feed material spiked volumetrically before extraction (a) and the same native material spiked after extraction (b); each set represent three repeated injections
Mentions: The improved chromatographic resolution resulted in significantly less ion suppression (Fig. 2). To restore comparability between the 20 μL injection volume for LC-LC and the 5 μL for LC, peak areas were normalized to area per μL injection volume. The left panel (a) shows the normalized peak areas of the spike ion in the feed material spiked volumetrically once before extraction, the right one (b) shows the same for the feed material spiked after extraction. Both plots show the severe suppression of the signal in 1D-LC. The fact that the LC-LC peak area for the “spike before extraction” is slightly smaller than for the spike added to the crude extract indicates that the extraction efficiency is not 100 % but still acceptable.Fig. 2

Bottom Line: This is evidenced by the expanded measurement uncertainty (k=2) of 0.017 μg/kg or 8.9 % relative to a mass fraction of aflatoxin B1 in a cereal-based baby food of 0.197 μg/kg.This value is in perfect agreement with the consensus value of this material from a proficiency test (PT) scheme for National Reference Laboratories executed by the European Reference Laboratory for Mycotoxins.The effort necessary to perform the described methodology precludes its frequent use but for specific applications we see it as a valuable tool.

View Article: PubMed Central - PubMed

Affiliation: European Commission, Joint Research Center, Institute for Reference Materials and Measurements, 2440 Geel, Belgium. andreas.breidbach@ec.europa.eu

ABSTRACT
Aflatoxins, mycotoxins of fungi of the Aspergillus sp., pose a risk to consumer health and are, therefore, regulated by more than 100 countries. To facilitate method development and validation as well as assessment of measurement capabilities, availability of certified reference materials and proficiency testing schemes is important. For these purposes, highly accurate determinations of the aflatoxin content in the materials used are necessary. We describe here the use of two-dimensional heart-cut LC-LC in combination with exact-matching double isotope dilution mass spectrometry to determine the content of aflatoxin B1 in three materials used in a proficiency testing scheme. The serious reduction in ionization suppression afforded by the two-dimensional heart-cut LC-LC had a positive effect on the precision of the measured isotope ratios of the exact-matching double isotope dilution mass spectrometry. This is evidenced by the expanded measurement uncertainty (k=2) of 0.017 μg/kg or 8.9 % relative to a mass fraction of aflatoxin B1 in a cereal-based baby food of 0.197 μg/kg. This value is in perfect agreement with the consensus value of this material from a proficiency test (PT) scheme for National Reference Laboratories executed by the European Reference Laboratory for Mycotoxins. The effort necessary to perform the described methodology precludes its frequent use but for specific applications we see it as a valuable tool.

No MeSH data available.


Related in: MedlinePlus