High-performance liquid chromatography ultraviolet-photodiode array detection method for aflatoxin B₁ in cattle feed...

The objective of the current study is to determine the concentration of aflatoxin B1 using high-performance liquid chromatography (HPLC) with a photodiode array (PDA) detector.

Aflatoxin B₁ certified reference grade from Trilogy Analytical Laboratory dissolved acetonitrile (ACN) at 10 µg/mL was using standard assessment. HPLC instruments such as ultraviolet-PDA detector used a Shimadzu LC-6AD pump with DGU-20A5 degasser, communication module-20A, and PDA detector SPD-M20A with FRC-10A fraction collector. The HPLC was set isocratic method at 354 nm with a reverse-phase ODS C18 column (LiChrospher^® 100 RP-18; diameter, 5 µm) under a 20°C controlled column chamber. Rheodyne^® sample loops were performed in 20 µL capacities. The mobile phase was performed at fraction 63:26:11 H₂O: methanol:ACN at pH 6.8. A total of 1 kg of feed contained 10% bread crumbs and 30% concentrated, 40% forage, and 20% soybean dregs were using commercials samples. Samples were extracted by ACN and separated with solid phase extraction ODS 1 mL than elution with mobile phase to collect at drying samples performed. The samples were ready to use after added 1 mL mobile phase than injected into the system of HPLC.

We found that the retention time of aflatoxin B₁ was approximately 10.858 min. Linearity of 0.01-0.08 µg/mL aflatoxin B₁ dissolved in mobile phase was obtained at R²=0.9. These results demonstrate that these methods can be used to analyze aflatoxin B₁ and gain 89-99% recovery. The limit of detection of this assay was obtained at 3.5 × 10^-6 µg/mL.

This method was easy to apply and suitable to analyzing at small concentrations of aflatoxin B₁ in formulated product of feed cattle.