UHPLC-MS/MS Determination of Ochratoxin A and Fumonisins in Coffee Using QuEChERS Extraction Combined with Mixed-Mode SPE Purification

Kristian Fog Nielsen, Archard Ferdinand Ngemela, Lene Bai Jensen, Lívia Soman De Medeiros, Peter Have Rasmussen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed by mixed-mode reversed phase-anion exchange solid phase extraction. OTA and FB2 were detected at levels down to 0.5 and 2 μg/kg by UHPLC-MS/MS and quantitated via isotope dilution using U−13C-labeled FB2 and OTA as internal standards. Mixing 20% isopropanol in the acetonitrile of the acidic UHPLC gradient system increased the signal intensity by 50% and decreased the ion-suppression with 50−75% in roasted coffee samples. About half of the roasted coffee samples (n = 57, from 9 countries) contained detectable levels of OTA, however, with only 5 samples above the EU regulatory limit of 5 μg/kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56% of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However, in the green coffee samples (n = 18) almost half of the samples were positive with a maximum value of 164 μg/kg (sum of FB2, FB4, and FB6). This discrepancy between green coffee and processed coffees indicated that the fumonisins decompose during the roasting process, which was confirmed in roasting experiments. Here fumonisins could not be detected after roasting of the green, 164 μg/kg coffee, sample. Under the same conditions, OTA was reduced from 2.4 to 0.5 μg/kg.
Original languageEnglish
JournalJournal of Agricultural and Food Chemistry
Volume63
Issue number3
Pages (from-to)1029-1034
ISSN0021-8561
DOIs
Publication statusPublished - 2015

Keywords

  • Coffee
  • Aspergillus niger
  • LC-MS/MS
  • Isotope dilution
  • Ochratoxin A
  • Fumonisin
  • QuEChERS
  • Mixed-mode reversed phase-anion exchange

Cite this

Nielsen, Kristian Fog ; Ngemela, Archard Ferdinand ; Jensen, Lene Bai ; Soman De Medeiros, Lívia ; Rasmussen, Peter Have. / UHPLC-MS/MS Determination of Ochratoxin A and Fumonisins in Coffee Using QuEChERS Extraction Combined with Mixed-Mode SPE Purification. In: Journal of Agricultural and Food Chemistry. 2015 ; Vol. 63, No. 3. pp. 1029-1034.
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title = "UHPLC-MS/MS Determination of Ochratoxin A and Fumonisins in Coffee Using QuEChERS Extraction Combined with Mixed-Mode SPE Purification",
abstract = "A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed by mixed-mode reversed phase-anion exchange solid phase extraction. OTA and FB2 were detected at levels down to 0.5 and 2 μg/kg by UHPLC-MS/MS and quantitated via isotope dilution using U−13C-labeled FB2 and OTA as internal standards. Mixing 20{\%} isopropanol in the acetonitrile of the acidic UHPLC gradient system increased the signal intensity by 50{\%} and decreased the ion-suppression with 50−75{\%} in roasted coffee samples. About half of the roasted coffee samples (n = 57, from 9 countries) contained detectable levels of OTA, however, with only 5 samples above the EU regulatory limit of 5 μg/kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56{\%} of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However, in the green coffee samples (n = 18) almost half of the samples were positive with a maximum value of 164 μg/kg (sum of FB2, FB4, and FB6). This discrepancy between green coffee and processed coffees indicated that the fumonisins decompose during the roasting process, which was confirmed in roasting experiments. Here fumonisins could not be detected after roasting of the green, 164 μg/kg coffee, sample. Under the same conditions, OTA was reduced from 2.4 to 0.5 μg/kg.",
keywords = "Coffee, Aspergillus niger, LC-MS/MS, Isotope dilution , Ochratoxin A, Fumonisin, QuEChERS, Mixed-mode reversed phase-anion exchange",
author = "Nielsen, {Kristian Fog} and Ngemela, {Archard Ferdinand} and Jensen, {Lene Bai} and {Soman De Medeiros}, L{\'i}via and Rasmussen, {Peter Have}",
year = "2015",
doi = "10.1021/jf504254q",
language = "English",
volume = "63",
pages = "1029--1034",
journal = "Journal of Agricultural and Food Chemistry",
issn = "0021-8561",
publisher = "American Chemical Society",
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UHPLC-MS/MS Determination of Ochratoxin A and Fumonisins in Coffee Using QuEChERS Extraction Combined with Mixed-Mode SPE Purification. / Nielsen, Kristian Fog; Ngemela, Archard Ferdinand; Jensen, Lene Bai; Soman De Medeiros, Lívia; Rasmussen, Peter Have.

In: Journal of Agricultural and Food Chemistry, Vol. 63, No. 3, 2015, p. 1029-1034.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - UHPLC-MS/MS Determination of Ochratoxin A and Fumonisins in Coffee Using QuEChERS Extraction Combined with Mixed-Mode SPE Purification

AU - Nielsen, Kristian Fog

AU - Ngemela, Archard Ferdinand

AU - Jensen, Lene Bai

AU - Soman De Medeiros, Lívia

AU - Rasmussen, Peter Have

PY - 2015

Y1 - 2015

N2 - A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed by mixed-mode reversed phase-anion exchange solid phase extraction. OTA and FB2 were detected at levels down to 0.5 and 2 μg/kg by UHPLC-MS/MS and quantitated via isotope dilution using U−13C-labeled FB2 and OTA as internal standards. Mixing 20% isopropanol in the acetonitrile of the acidic UHPLC gradient system increased the signal intensity by 50% and decreased the ion-suppression with 50−75% in roasted coffee samples. About half of the roasted coffee samples (n = 57, from 9 countries) contained detectable levels of OTA, however, with only 5 samples above the EU regulatory limit of 5 μg/kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56% of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However, in the green coffee samples (n = 18) almost half of the samples were positive with a maximum value of 164 μg/kg (sum of FB2, FB4, and FB6). This discrepancy between green coffee and processed coffees indicated that the fumonisins decompose during the roasting process, which was confirmed in roasting experiments. Here fumonisins could not be detected after roasting of the green, 164 μg/kg coffee, sample. Under the same conditions, OTA was reduced from 2.4 to 0.5 μg/kg.

AB - A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed by mixed-mode reversed phase-anion exchange solid phase extraction. OTA and FB2 were detected at levels down to 0.5 and 2 μg/kg by UHPLC-MS/MS and quantitated via isotope dilution using U−13C-labeled FB2 and OTA as internal standards. Mixing 20% isopropanol in the acetonitrile of the acidic UHPLC gradient system increased the signal intensity by 50% and decreased the ion-suppression with 50−75% in roasted coffee samples. About half of the roasted coffee samples (n = 57, from 9 countries) contained detectable levels of OTA, however, with only 5 samples above the EU regulatory limit of 5 μg/kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56% of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However, in the green coffee samples (n = 18) almost half of the samples were positive with a maximum value of 164 μg/kg (sum of FB2, FB4, and FB6). This discrepancy between green coffee and processed coffees indicated that the fumonisins decompose during the roasting process, which was confirmed in roasting experiments. Here fumonisins could not be detected after roasting of the green, 164 μg/kg coffee, sample. Under the same conditions, OTA was reduced from 2.4 to 0.5 μg/kg.

KW - Coffee

KW - Aspergillus niger

KW - LC-MS/MS

KW - Isotope dilution

KW - Ochratoxin A

KW - Fumonisin

KW - QuEChERS

KW - Mixed-mode reversed phase-anion exchange

U2 - 10.1021/jf504254q

DO - 10.1021/jf504254q

M3 - Journal article

C2 - 25553918

VL - 63

SP - 1029

EP - 1034

JO - Journal of Agricultural and Food Chemistry

JF - Journal of Agricultural and Food Chemistry

SN - 0021-8561

IS - 3

ER -