Application of GC-NPD coupling with solid phase micro-extraction SPME for detection and identification of phosphine

Abstract

Introduction: Commercial phosphine in Morocco is mainly used as a crop protection product and as a fumigant in the food and agricultural industry. It is used to eliminate harmful organisms such as insects, rodents and fungi that can damage crops, cereals and stored products.

In Morocco, commercial phosphine is sold by companies specialising in agricultural chemicals and pest control services. It is also widely sold in small-scale distributors (drugstores) and in urban and rural markets.

Objectives:  Phosphine (PH3) is an inorganic compound with unique chemical properties and a variety of         industrial and domestic applications. The study of phosphine is of crucial importance because of its potential for intoxication and its effects on human health. The aim of this study is to evaluate the use of headspace GC-NPD coupled to SPME for the detection and quantification of phosphine in various biological (liquid gastrointestinal) and food (vegetable and fruit) samples.

Methods: Headspace GC-NPD coupled with SPME offers many advantages, such as high sensitivity, high selectivity, rapid analysis and low sample consumption. However, this technique can present certain limitations, particularly with regard to the separation of non-volatile compounds and the complexity of optimising experimental parameters.

Results: The use of headspace GC-NPD coupled with SPME allows accurate detection and quantification of phosphine in various samples. The method described, using sulphuric acid (H2SO4) and gas chromatography with nitrogen flame panel detection (GC-NPD), allows reliable identification of phosphine in biological fluids. 

Conclusions: This combination of GC-NPD and SPME offers high sensitivity, high selectivity and rapid analysis, while minimising the problems associated with analyst handling and the risks associated with sample consumption. This method allows efficient separation of sample components, as well as low sample consumption. However, limitations remain, such as the separation of non-volatile compounds and difficulties in optimising certain analytical parameters.  Further research can be carried out to improve this method, particularly with regard to the separation of non-volatile compounds and the optimisation of parameters linked to the use of a SPME solid phase. In addition, other potential applications of the method can be explored, such as the detection of phosphine in other matrices and the adaptation of the method for more complex samples.