A novel rapid, simple and solvent-free method was developed for determination of the volatile compounds from the flowers of Chimonanthus praecox Link using headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The SPME conditions were firstly optimized and applied to sampling of the volatile compounds emitted from living Chimonanthus praecox L. flower...

background & aim:nepeta racemosa is an herbal and medicinal plant and this report aims to   identify chemical compositions of the essential oils and volatiles of its   aerial parts through classical and advanced methods.  experimental: chemical profiles of the essential oils and volatile compounds from the aerial parts of nepeta racemosa obtained through hydrodistillation (hd), solvent-free mic...

In order to achieve rapid, automatic, and efficient extraction for trace chemicals from samples, a system of gas-purged headspace liquid phase microextraction (GP-HS-LPME) has been researched and developed based on the original HS-LPME technique. In this system, semiconductor condenser and heater, whose refrigerating and heating temperatures were controlled by microcontroller, were designed to ...

The unique flavor of the proso millet (Panicum miliaceum L.) is one key reasons why consumers prefer it. Fatty acids and amino have an important influence on nutrition millet. In this study, we identified fatty acids, volatile compositions in waxy non-waxy porridge by a headspace solid phase microextraction (HS-SPME) method conjunction with gas chromatography-mass spectrometry (GC-MS). We 8 7 e...

Since solid-phase and liquid-phase microextraction (SPME and LPME) were introduced, as effective solvent-free methods, many efforts have been made to improve their modes and applications. However, due to limitations with sensitivity and efficiency, researchers have focused on improving the performance of their basic primary modes. In this way, in recent years, different methods such as ultrason...

AIMS A novel method has been developed that allows successful differentiation between Clostridium difficile culture-positive and culture-negative stool samples based on volatile organic compound (VOC) evolution and detection by headspace solid-phase microextraction coupled with gas chromatography mass spectrometry (HS-SPME-GC-MS). METHODS AND RESULTS The method is based on the activation of p...

Xylopia aromatica (Lam.) Mart. (Annonaceae) is a typical species from the Brazilian cerrado that presents medicinal properties. The plant distinguished by its large white flowers which produce pleasant fragrance. X. characterized wide range of application. These characteristics have motivated us to investigate volatile organic compounds (VOCs) via in vivo and vitro protocols headspace solid-pha...

Abstract A recently proposed combination of headspace liquid-phase microextraction with an optical immersion probe (HS-LPME-OIP) was adapted for the spectrophotometric determination ammonium. The developed method is based on conversion ammonium ions to ammonia in a 0.15 M sodium hydroxide solution, followed by absorption 200 µL Nessler's reagent solution preliminary diluted distilled water (1:1...