Trace Elements

For ppm and ppb analyte determinations, enrichment and highly sensitive methods like ICP, AA and/or Ion chromatography (IC) are used to improve detection limits. Depending on the matrix and special problems, sample preparation may involve selective speciation or dissolution. PH, complexation, solid phase extraction or solvent extraction, and separation techniques are used to enhance selectively the recoveries of certain analytes. To bring samples into solution we use open vessel acid reflux digestion; for volatile elements, high pressure pulsed microwave digestion is used.

Metals

Metals are determined quantitatively to sub-ppm levels by Atomic Absorption (AA) or simultaneously at several emission lines per element by Inductively Coupled Plasma Emission Spectroscopy (ICP-OES).

Titration methods can be used for certain applications.

A large variety of techniques are used for sample preparation to bring metals into solution prior to instrumental detection.

Sample requirement is 2-9 mg assuming that 5% of the element is present.

Ions

Anions and/or Cations are detected at ppm levels by Ion chromatography (IC) and also by titration or photometric assays.

Based on a sample weight of 10 mg, the reported limit is 0.02%