Titanium Determination for Correction of Plant Sample Contamination by Soil¹

Abstract

An accurate method for determining Ti in plant material and soil was developed. Titanium concentrations in plant and soil were used to correct analytical data of plant materials for contamination by soil. Different digestion schemes were used in the analysis of National Bureau of Standards (NBS) reference materials for Ti. A satisfactory result was obtained when the sample was digested in a Teflon beaker containing HNOz and HCIO,, taken to dryness, baked at 185" C, and then dissolved overnight at room temperature in HF. The solution was made to volume with 3M HCI, in polyethylene, after addition of H3BO3 to complex excess F . Titanium was determined by inductively coupled argon plasma (ICP) spectrometry. Certified Ti values for NBS mineral samples 120b and 692 are 899 and 270 mg kg I, respectively. This method gave values of 898 f 14 and 264 k 6 mg kg I, respectively. Correction of elemental analysis for soil contamination of plant, rumen fistula, and feces samples using this method agreed well with corrections using Fe or AI as a reference element as well as with determination for Ti by x-ray fluorescence. Using residual ash content (Si) as a reference element appeared to be less reliable. The assumptions needed to make this correction using Ti are less prone to error than the assumptions needed when Fe, AI, or residual ash are used. It was imperative to use HF in the digestion procedure for quantitative determination of Ti in some samples.

Transfer of elements relevant to nuclear fuel cycle from soil to boreal plants and animals in experimental meso- and microcosms

“…Thorium concentrations were below the detection limit for the majority of plant leaf samples, few birch root samples and for whole snail data. Plant titanium (Ti) concentration N 10 mg kg −1 was used as an indicator of soil contamination (Cary et al, 1986) as living organisms only take up small amount, less than 3 mg kg −1 , of Ti (Nisbet and Shaw, 1994;Cook et al, 2007).…”

Physiological Characteristics of Fe Accumulation in the `Bronze' Mutant of Pisum sativum L., cv `Sparkle' E107 (brz brz)

“…The concentrations of K, Ca, Mg, P, S, Fe, Mn, Cu, Ti, and Zn in the digestates were determined by simultaneous, inductively-coupled, argon-plasma, emission spectrometry. Concentrations of the elements determined in leaf material harvested from plants grown outdoors in soil were corrected for soil contamination by the titanium correction method of Cary et al (6).…”

Potential errors caused by roots in analyses of rhizosphere soil

“…Concentrations of P and the micronutrient metals tended to be higher in the leaves than in the roots (Table 1). This was true even for Fe, which supports the contention that the very high Fe levels often reported in soil-grown roots are probably a result of contamination by soil Fe (Cary et al, 1986;Mitchell, 1960). Brown and U1-Haq (1984) found moderately high levels of Fe in soybean roots grown in filter envelopes, but much of this Fe may have been mobilized by the moist conditions maintained, and then deposited on external root surfaces.…”

“…However, this same close association complicates the experimental study of effects that roots have on the soil, and simultaneously hinders measurement of the composition of roots and the total uptake of elements by plants. The contamination of soil-grown roots by soil particles creates serious, sometimes insurmountable, analytical problems in determining the concentrations of elements in roots (Cary et al, 1986;Mitchell, 1960). Likewise, the presence of root materials in rhizosphere soil samples has the potential to interfere with measurement of chemical changes in the soil.…”