Determination of gamma-butyrolactone (GBL) in foods by SBSE-TD/GC/MS

4-hydroxybutyric acid lactone, or gamma-butyrolactone (GBL), is a molecule included in the FEMA (Flavor Extract Manufacturers Association) list of flavouring substances (No. 3291) and used as natural-identical substance in flavouring formulation. Recently, the use of GBL has been subjected to restrictions by FDA because, together with the conversion derivative GHB (gamma-hydroxybutyric acid), it has been recognized and classified as psychotropic. In 1999 the Italian law included GBL in the list of psychotropic substances and more recently in the Table of substances inducing psychic and physical addiction. However, GBL has been detected in several natural products. Under a toxicological point of view the difference between natural and natural-identical GBL in food is not relevant. In any case, the evaluation of the total content of GBL in many foods contributes to evaluate the consumption ratio and the aim of this paper is to evidence the possibility of detecting GBL with a high sensitivity method also in complex matrices with analytical procedure characterized by high recovery. This paper proposes a new, simplified, sensitive and selective method (SBSE-TD/GC/MS) useful to detect and quantify the GBL in foods. The work shows, as an application of this method, the detection of this molecule in the very complex matrix of a confectionery product on the international market. The reliability of the method was verified by recovery and repeatability tests. Recovery average values result between 85–92% (CV%=8.2–5.3) for the concentration range 1–10mg/l and between 92–95% (CV%=6.5–4.2) for the concentration range 10–25mg/l.