RESUMEN
The natural rubber molecule is one of the end products of isoprenoids metabolism in the plant. Dimethylallyl diphosphate (DMAPP) and farnesyl pyrophosphate (FPP) are two typical isoprenoids which control the rate of biosynthesis and the molecular weight of natural rubber. A rapid, nonradioactive method for quantitation of DMAPP and FPP in natural rubber latex by liquid chromatography tandem with mass spectrometry (LC-MS/MS) was reported. DMAPP and FPP were determined in the multiple reaction monitoring mode(MRM)followed by separation with a silica-based C18 column. The external standard quantitative method was established, and the results showed limits of quantitation (LOQs) were 28â¯ng/ml and 33â¯ng/ml for DMAPP and FPP, respectively. The concentrations were detected 70-96â¯ng/ml and 242-375â¯ng/ml for these two isoprenoids in natural rubber latex. Recoveries of the method were in the range 81-93%. Daytime comparison experiments found that FPP had better stability than DMAPP.
Asunto(s)
Cromatografía Liquida/métodos , Hemiterpenos/análisis , Látex/química , Compuestos Organofosforados/análisis , Fosfatos de Poliisoprenilo/análisis , Goma/química , Sesquiterpenos/análisis , Espectrometría de Masas en Tándem/métodos , Calibración , Hemiterpenos/química , Límite de Detección , Peso Molecular , Compuestos Organofosforados/química , Fosfatos de Poliisoprenilo/química , Sesquiterpenos/químicaRESUMEN
Natural trans-1,4-polyisoprene (TPI) as a functional biomaterial has aroused great interest for rubber industrial product use. Here, we proposed a method that enables simultaneous analysis of the content and molecular-weight distribution (MWD) of natural TPI by gel permeation chromatography (GPC). The natural TPIs were collected from leaves, fruit coatings and bark of Eucommia ulmoides Oliver (E. ulmoides) through toluene extraction followed by ethanol purification. The results of TPI contents from leaves and fruit coatings were shown ca. 3.5% and 13.8%, respectively. Accordingly, limits of detection (LODs) of TPI were 0.58mg/mL from leaves and 0.47mg/mL from fruit coatings. The MWDs of TPI demonstrated a bimodal distribution from leaves, a unimodal distribution from bark, and a unimodal distribution with a tiny peak shoulder from fruit coatings. In real-life E. ulmoides analysis, the results from three independent methods (GPC, gravimetric method, and infrared spectroscopy) were obtained with good consistency.