Carbon Fiber Microextraction/Headspace In-situ Derivatization Technique For GC-MS Determination Of Phytohormones

Phytohormones play a vital role in plant growth and metabolic processes. It is usually rather difficult to determine phytohormones in plant tissues owing to their presence in trace amounts and to the coexistence of a wide variety of interferents. Traditional hormone determination methods have involved multiple steps of intensive purification and large amounts of plant tissue. In order to achieve the rapid extraction, separation and highly sensitive detection, an integrated sample pre-treatment method including solid phase microextraction (SPME) and separation/headspace derivatization was developed. Carbon fiber (CF) which have excellent high thermal and chemical stabilities, high porosity and low cost were used as adsorbent, and N,O-bis(trimethylsilyl)trifluroacetamide (BSTFA) was used as and derivatization reagent, respectively. The three kinds of phytohormones were simultaneously extracted and separated, and rapid derived to corresponding derivatives in situ, and the derivatives are directly subjected to Gas Chromatograph-Mass Spectrometer (GC-MS) analysis. This method demonstrated high enrichment factor, high derivatization rate (≥90%), fast (reaction time≤1min), good reproducibility and it have several advantages such as easy automation and favor for coupling with GC-MS. Based on the results, the micro-injector type of carbon fiber enrichment/headspace derivatization device was manufactured in our Lab, and it was applied to real-time monitoring of the phytohormones from the plant nutrient solution.