LC/MS/MS Analysis of Aflatoxins in Hops on Ascentis^® Express 2.7 μm Phenyl-Hexyl after Cleanup Using Supel^™ Tox AflaZea SPE

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