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Energy is the driving force of economic and social development and crucial for human survival. Catalytic reaction is a key part of energy production, so it is urgent to obtain...

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Based on microwave-assisted extraction (MAE) and headspace solid-phase microextraction (HS-SPME) followed by gas chromatography mass spectrometry (GC-MS) was developed for the fast determination of volatile chemical compositions of Polygala furcata Royle, the experimental parameters of the MAE-HS-SPME were optimized by orthogonal experimental design. The results indicated that the optimum condition of the determination of the volatile compounds in P. furcata Royle. was achieved with the experimental parameters including microwave power of 400 W and irradiation time of 4 min, sample size 2.0 g. Under the optimal conditions, for the Wrst time, 52 volatile compounds were separated and identiWed from the fresh plants of P. furcata Royle. The highest content component of the 52 compounds was 2-hydroxybenzoic acid methyl ester (21.65%). The relative standard deviation values <7% showed that the method of MAE-HS-SPME followed by GC-MS has good precision. The experimental results demonstrated that it is a simple, time-saving and solvent-free method, and it is a potential analytic tool for the determination of the volatile compounds of the vegetations materials and other materials.

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Microwave-assisted extraction (MAE) and headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) was developed for the rapid determination of the volatile chemical compositions of Gymnotheca involucrata Pei. The experimental parameters of the MAE-HS-SPME were optimized by orthogonal experimental design. The results indicated that the optimal experimental parameters for determination of the volatile constituents of Gymnotheca involucrata Pei. were: sample weight 2.0 g, microwave power of 400 W and irradiation time of 3.0 min. Employing these conditions, 106 volatile constituents in the dry stems and 103 volatile constituents in the dry leaves of Gymnotheca involucrata Pei. were separated and identified, amounting to 93.58 and 98.53% of the total peak areas, respectively. The major components found in the oil extracted from the stems and leaves were nerolidol (16.57, 17.50%), sabinene (3.35, 3.65%), cis, cis, cis-1,1,4,8-tetramethyl-4,7,10-cycloundecatriene (4.64, 5.03%), acopaene-8-ol (6.01, 6.33%) and phytol (2.92, 3.03%), respectively. Relative standard deviation (RSD) values of \9.0% showed that the MAE-HS-SPME method followed by GC-MS has good precision. The experimental results demonstrated that this solvent-free method is simple, timeefficient, and is a potentially suitable analytical tool for the determination of volatile compounds from vegetative and other materials.

In order to solve the intensifying problem of heavy metal pollution of soil in mining areas, a method for monitoring air quality and soil environment in mining areas based on the Internet of Things is proposed. Using meta-analysis method and health risk assessment method, the impact of mining on soil heavy metal content in Southwest China was quantitatively analyzed, and the relationship between soil heavy metal value and its potential influencing factors was discussed, as well as the heavy metal pollution, ecological risk, and health caused by soil mining activities. Risks were assessed. The results showed that artificial and oral intake were the main modes of soil heavy metal exposure, with the highest daily intakes for noncarcinogenic risk children and the highest daily intakes for carcinogenic risk adult females. The noncarcinogenic risk (HQ>1) of soil As and Pb exposure to children was 3.74 and 1.44, respectively. The carcinogenic risk values of As, Cd, Cr, and Ni in soil were all higher than 10-6, indicating that the carcinogenic risk was within the tolerance range of human body. Children were exposed to the combined noncarcinogenic risk ( HI = 3.83 ), and the risk values of the three types of recipients were 1.19 × 10 − 4 , 1.21 × 10 − 4 , and 1.06 × 10 − 4 , respectively. The correlation between heavy metal content and environmental factors was obtained. It is verified that the system in this paper can effectively monitor the meteorological environment and soil environment, and at the same time, it reveals the pollution law of heavy metals in the soil of the mining area, which provides supporting conditions for future mining and heavy metal pollution management.