Isotopic determination of silicon by mass spectrometry in plants and soils labeled with 30Si

A method for isotopic determination of silicon by mass spectrometry in plants and soils labeled with Si-30 is reported. The development of this method is for use with studies involving the physiological process of absorption, transport, and redistribution of Si in the soil-plant system by use of the stable isotope Si-30 as a tracer. The procedure leads to SiF4 formation, and the isotopic determination of Si was based on the measurements of the (SiF3+)-Si-28, (SiF3+)-Si-29, and (SiF3+)-Si-30 signals. Relative standard deviation of Si-30 abundance measurements (n = 6) were lower than 0.1%, and the detection limit was 0.5 mg Si (dry mass).