Successive cartridge clean-up method for the simultaneous determination of matrine and oxymatrine in biopesticides containing Sophora flavescens extract was developed and validated by UPLC. The clean-up method was established with ENVI-Carb (0.5 g) and C18 SPE (0.5 g) cartridges for the bioactive alkaloid in biopesticides from S. flavescens, and the eluate was analyzed to quantify the matrine and oxymatrine by UPLC. The developed method was validated, and the recovery and LOQ of both materials were 105.0% and 103.6%, and 0.050 and 0.684 mg·kg −1 , respectively. Of the twenty one samples, the total content of matrines were analyzed by using the developed method and the result showed
The quantitative analytical method for the bioactive substance, 3-cyano-4-methoxy-N-methyl-2-pyridone (ricinine) and an index compound, ricinoleic acid in castor plant (Ricinus communis) extract or oil was developed. For the determination of a pyridone alkaloid compound, ricinine, successive cartridge cleanup method combined with ultra-performance liquid chromatography was set up with ENVI-Carb TM (0.5 g) and C 18 SPE cartridges. Accuracy and precision were evaluated through fortification studies of one biopesticide (PE) at 10 and 100 mg kg −1. Mean recoveries of ricinine were 98.7 and 96.0 % associated with less than 10 % RSD, respectively. For the determination of ricinoleic acid in castor extract and oil, saponification and methylation were optimized using gas chromatography-time of flight mass spectrometry. Recovery was more than 84.8 % associated with 6.2 % RSD after derivatization procedure. Both methodologies developed were applied to analyze real samples including three castor oil products and six commercially available biopesticides containing R. communis, collected at Korean market. The contents of ricinine and ricinoleic acid in most commercial biopesticides were less than the oil or extract contents indicated by label.
We designed a new rapid detection method for volatilized formaldehyde from wood. The process was installed with volatilizing and collecting parts in an incubator. For rapid sampling of formaldehyde from wood, we pulverized the wood to sawdust, and used 0.15-2.0 mm particles for the tests. The highest sampling rate (94.8%) was obtained at 40 mL/min flow rate and 100 o C. Under the optimized condition, we could collect the volatilized formaldehyde with good recovery rate. The developed method was applied to the monitoring of the formaldehyde from wood, and the measured concentrations were 0.7-4.6 µg/g from natural wood, 5.9-12.3 µg/g from preserved wood, and 5.9-211.5 µg/g from chemical adhesive processed wood. From the results, we identified natural wood sawdust and chemically processed wood (medium density fiberboard, high density fiberboard, particle board) by the formaldehyde contents except preserved wood.
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