We used calibration curve prepared in water in contrary to the
recommendations of Wenzl (2008). This was because the standard
addition method was not found suitable as the determination was
accomplished manually and therefore the suggested method
would have restricted the laboratory efficiency dramatically. In
addition, as the recovery of furan from the spiked samples was
around 100% at all spiking levels, it is unlikely, that the matrix
would affect the quantitative result. Crews, Hasnip, Roberts, and
Castle (2007) compared these two different quantification methods
(standard addition and calibrants prepared in solvent) and
found that they both provide nearly identical results and suggested
that the relative partitioning of furan and deuterated furan is not
significantly affected by the nature of the sample matrix. Additionally,
Limacher et al. (2007) used calibrants diluted to water to perform
a reliable quantitative analysis of furan in vegetable purée.