LC/MS/MS Analysis of Aflatoxins in Hops on Ascentis® Express 2.7 μm Phenyl-Hexyl after Cleanup Using Supel™ Tox AflaZea SPE
Materials
Analytical column
Ascentis® Express Phenyl-Hexyl, 2.7 μm HPLC Column
2.7 μm particle size, L × I.D. 5 cm × 2.1 mmStandard
accessory
Vials, screw top, silane-treated
volume 2 mL, amber glass vial, O.D. × H × I.D. 12 mm × 32 mm × 4.6 mmCONDITIONS
sample/matrix
hops extract was spiked with aflatoxins at corresponding concentrations of 6 ppb each (for Aflatoxin B2 and G2) and 24 ppb each (for Afltoxin B1 and G1) in hops
SPE tube/cartridge
Supel Tox AflaZea SPE, 6 mL (55314-U)
extraction process
0.5 g of finely ground hops is mixed with 10 mL of 84:16 acetonitrile:water for 30 minutes, centrifuged
sample addition
2 mL of hops sample extract
elution
apply strong vacuum and collect the sample into plastic tube
sample preparation
dilute 0.2 mL of the extract with 0.8 mL distilled water and mix well
column
Ascentis Express Phenyl-Hexyl, 5 cm x 2.1 mm I.D., 2.7 μm particles (53334-U)
mobile phase
[A] 5 mM ammonium formate with 1% formic acid in water; [B] 5 mM ammonium formate with 1% formic acid in methanol
gradient
30% B to 60% B in 3 min; to 100% B in 2 in; held at 100% B for 2 min; to 30% B in 0.1 min; held at 30% B for 1.4 min
flow rate
0.4 mL/min
pressure
5511 psi (380 bar)
column temp.
40 °C
detector
MS, ESI(+), MRM 331.3/189.0, 329.1/243.0, 315.9/259.0, 313.1/241.0
injection
10 μL
Description
Analysis Note
The complex composition of hops makes it difficult to apply sample cleanup methods commonly used for other commodities. In this application, interference removal on Supel Tox AflaZea SPE was used for sample cleanup providing quick and effective sample preparation prior to separation on an Ascentis Express Phenyl-Hexyl column and mass spectrometric detection. It is recommended to use silanized glass vials for this analysis.
Other Notes
Use silanized vials for analysis.
Legal Information
Ascentis is a registered trademark of Merck KGaA, Darmstadt, Germany
Supel is a trademark of Sigma-Aldrich Co. LLC