Spices of The Christmas Season
The scent of Christmas spreads everywhere. The Christmas markets are open and tempt with mulled wine, cookies and other delicacies. Ginger, cinnamon, aniseed and cloves are among the most popular Christmas spices.
However, spices are often susceptible to the occurence of mycotoxins such as aflatoxin B/G and ochratoxin A, especially when improperly processed or stored. For this reason, the maximum levels of mycotoxins are strictly regulated by law. However, dyestuffs, essential oils or other matrix interferences contained in the spices often make an investigation rather challenging.
Clean-up of Aflatoxins B/G and Ochratoxin A
Aflatoxins and ochratoxin A are often found together in spices. To facilitate the work and to halve the working time, LCTech has developed the combined immunoaffinity column Afla-OtaCLAN for the clean-up of aflatoxin B1, B2, G1, G2 and ochratoxin A simultanously in comparison to the AflaCLEAN and OtaCLEAN columns.
The columns are available in the convenient 3 mL polypropylene format, they can be processed automatically (e.g. with the LCTech robotic system FREESTYLE SPE) and can be stored at room temperature for 18 months from the date of manufacture.
The chromatographic results are excellent, without interfering signals and with high recoveries, even for difficult matrices such as spices. Convince yourself on the following pages. We have taken a closer look at ginger and aniseed using the immunoaffinity columns AlfaCLEAN, OtaCLEAN and Afla-OtaCLEAN to compare the column clean-up performance and recoveries of aflatoxin B/G and ochratoxin A.
Homogenise 10 g of matrix (ginger or aniseed) and add 2 g of sodium chloride. Extract the sample through 100 mL of methanol/water (80/20 (v/v)) and add 25 mL n-hexane in order to remove fat and essential oils. For high extraction efficiencies, continue the extraction for 30 minutes.
Filtrate the raw extract and dilute 2 mL of it with 12 mL of PBS (contains 8 % Tween20). Load 14 mL of the sample (represents 0.2 g of matrix) onto the respective immunoaffinity column Afla-OtaCLEAN, AflaCLEAN or OtaCLEAN. Wash the column with 10 mL deionised water each and dry it afterwards by flushing air through it.
Elute the toxin with 2 mL of methanol. Keep in mind that the column bed is incubated with methanol for 5 minutes to ensure a fully denaturation of the antibodies and release of toxins.
Dilute the sample to eluent conditions and measure it afterwards via HPLC with fluorescence detection or LC-MS.