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Many flavour regulations around the world contain a list of so-called ‘restricted substances’ (RS), i.e. substances that occur naturally in source materials for flavourings and food ingredients with flavouring properties, but whose presence in certain foods is restricted and/or for which maximum levels are set, for example, the European regulation 1334/2008. Only a few publications refer to the determination of RS in compound flavourings or their raw materials, and the latter only concern the analysis of one or two individual RS in single essential oils. The Working Group on Methods of Analysis of the International Organization of the Flavor Industry (IOFI) has developed a method for the rapid routine determination of β-asarone, coumarin, menthofuran, methylchavicol, methyleugenol, pulegone, safrole and α- and β-thujones in flavourings and their raw materials by gas chromatography-mass spectrometry (GC-MS), using selected-ion monitoring and internal standards. The method has been evaluated by nine flavour-industry laboratories using a complex surrogate flavouring containing all of the above analytes, at concentrations that would be likely to produce levels in finished foods of around typical maximum limits for these RS. Results were obtained from a total of 15 columns and sets of analytical conditions, using 11 GC/MS instruments, with in each case a determination of the analyte in two versions of the flavouring. With reproducibility relative standard deviations (RSDR) of less than about 20%, and recoveries of 80–120%, the method performance can be considered as satisfactory for rapid routine checks on the levels of restricted substances in compound flavourings. The method is intended for flavour-industry laboratories in order for them to fulfil their obligation to inform food-industry clients of the amounts of these substances in commercial flavourings, but is not intended for their analysis in finished foods. Copyright © 2014 John Wiley & Sons, Ltd.

The performance of HPLC-UV as a means of quantifying selected furocoumarins in essential oils has been evaluated, based on a ring test validation approach. Accuracy profiles were generated, to determine bias and statistical confidence associated with determination at different concentrations, along with lower limits of quantification (LOQ). From these findings, it can be concluded that the method described may only be used in simple cases (essential oils), to measure individual furocoumarin compounds at concentrations greater than 10mg/l; the non compound-specific nature of detection by absorption in the UV range is unable to overcome the effect of interferences arising from chromatographic coelutions, such as those encountered in the analysis of complex commercial fragrance mixtures. The use of an algorithmically calculated 'spectral similarity' function, with reference to authentic standards, may be used to improve reliability in assignment and quantification.

Simultaneous distillation-extraction (SDE) combines, in a single step, hydro-distillation of volatiles from a sample with continuous solvent extraction of the solutes dissolved in the aqueous distillate. The solvent extract containing the isolated flavour volatiles can be subsequently analysed by gas chromatography. The technique is applicable to compounds possessing a wide range of volatility, but it is suitable neither for compounds of low volatility (e.g. vanillin), nor for highly volatile materials (e.g. methanethiol). The present guidelines concern the isolation of flavouring substances by simultaneous distillation-extraction (SDE), based on the experience of the authors in laboratories of the flavour industry. Copyright © 2014 John Wiley & Sons, Ltd.

The performances of the GC-MS determination of suspected allergens in fragrance concentrates have been investigated. The limit of quantification was experimentally determined (10 mg/L), and the variability was investigated for three different data treatment strategies: (1) two columns and three quantification ions; (2) two columns and one quantification ion; and (3) one column and three quantification ions. The first strategy best minimizes the risk of determination bias due to coelutions. This risk was evaluated by calculating the probability of coeluting a suspected allergen with perfume constituents exhibiting ions in common. For hydroxycitronellal, when using a two-column strategy, this may statistically occur more than once every 36 analyses for one ion or once every 144 analyses for three ions in common.

In the Gazette (176) for May, 1925, Miss J. M. Brown wrote a delightful article on “ Mathematical Clubs ” in Schools. It is interesting today to recall some of the ideas mentioned.“ The obvious function of a Mathematical Club is to stimulate the interest which may have been aroused in the classroom, or if possible to awaken an interest hitherto dormant.”The History of Mathematics was considered a starting point but was not found to be a very suitable topic for arousing enthusiasm. Mention is made of graph work (there was no Cundy and Rollett, Mathematical Models, in those days)—and of interest shown in Flatland (Dr. Abbott).