T. R. Mon

VOLATILES FROM STRAWBERRIES. II. COMBINED MASS SPECTROMETRY AND GAS CHROMATOGRAPHY ON COMPLEX MIXTURES.

Abstract The technique of combined mass spectrometry and gas chromatography has been applied to the analysis of a complex oil of strawberry volatiles. Capillary gas chromatography indicated over 150 components. Most of the major components have been identified. These include alcohols, esters, acetals, aldehydes, furfural, methyl furfural, aromatic aldehydes, ketones, and esters, a few terpenes, and a few aromatic hydrocarbons. The strength of this technique is shown by the determination of several compounds in one sharp chromatographic peak. On the other hand certain prominent species could not bbe identified by the low resolution (resolution about 200) mass spectral data obtained.

DIRECT VAPOR ANALYSES WITH GAS CHROMATOGRAPHY.

The need for an easy, quick, quantitative and objective measure of aroma quality is apparent to all involved with food research. Although the final judging must be with human senses, a permanent record of a simple instrumental analysis is desirable. The obvious approach is the application of gas-liquid chromatography (GLC), especially since the advent of the very sensitive ionization detectors. The problem is as difficult as the need is easy to define; for, although the human olfactory senses are not as acute as those possessed by some animals, the thresholds of detection for 5ome compounds are far beyond any present GLC instrument. Also, very few of the constituents responsible for certain aromas of food have been identified with much certainty. Therefore, detection and recording volatile constituents are only part of the problem. Identification and correlation to organoleptic characteristics constitute the other part, and an arduous part, indeed. In this paper, we wish to discuss some of the problems encountered in detecting and recording food volatiles, the parameters which must be considered in order to utilize the sensitivity possible with the ionization detectors, and some examples of direct vapor sampling analyses.