Standards Development

Scope

This document specifies a method for the determination of furan as well as of two isomeric furan derivatives (2-methylfuran, 3-methylfuran) in coffee and coffee products by gas chromatography with in-line mass-selective detection (GC-MS). This method is based on an automated static headspace technology; the quantification is carried out based on a multi-point calibration method using deuterated internal standards.

It is applicable to roasted coffee products as well as coffee extracts. In addition, the method described is applicable, e.g. to coffee beverages produced in accordance with DIN 10792. The method has been validated in an interlaboratory study. Relative reproducibility standard deviations of sR,rel ≤ 30% are expected when applying this method for the following working ranges, with the exception of 2-methylfuran in the low working range: 

Furan: 50 μg/kg to 4 500 μg/kg

2-Methylfuran: 850 μg/kg to 21 800 μg/kg

or

150 μg/kg to 850 μg/kg (sR,rel ≤ 40%), respectively

3-Methylfuran: 7 μg/kg to 700 μg/kg

If required, the working range can be extended by suitable measures, e.g. by using larger or smaller sample weights (m), decreasing or increasing the GC injection volume, etc

Purpose

The proposed test method corresponds to the determination of not only furan in coffee and coffee products, but also to the determination of two isomeric methylfuran derivatives (2- and 3- methylfuran) in coffee, coffee products and, additionally, in thereof prepared coffee beverages. The method further simplifies the feasibility of the method laid out in EN 16620 by utilizing a simple, easy to apply calibration technique, thus renouncing the necessity of applying laborious, thus time-consuming standard addition calibration techniques. Furthermore, the proposed method greatly expands the quantitative scope in determining furan itself in coffee products.