Metal Speciation Resources
Metal Speciation Resources: Metals Speciation is the process of quantifying each of the individual oxidation states of a metal that are found in a sample. This application is especially beneficial when a particular form of the metal:
- Has a therapeutic benefit
- Imparts a desirable quality or characteristic to a product or process
- Represents an enhanced risk over other forms of the metal
There are many methods of speciating metals in a sample. The factors that must be evaluated when deciding the best analytical route include:
- The element(s) that are under study
- The matrix (sample) the metal is present in
- Special handling/preparation requirements to prevent or minimize conversion of one species to another oxidation state
Cornerstone Analytical relies on ion chromatography to separate metal species. Detection can be made by conductivity, UV or Pulsed Amperometric Detector (PAD).
Ideally, samples should be dissolved in mobile phase before analysis. If a sample is not soluble in the mobile phase, it may be extracted into mobile phase using heat, sonication or combination thereof. Results generated in this fashion are reported as extractable. Aggressive preparation techniques are avoided to ensure that the preparation does not cause oxidation/reduction of the target metal(s). A QC standard or matrix spike of the same oxidation state as the analyte may be included in the analytical batch to monitor for changes in oxidation state of the analyte.
Mass of sample: the typical sample mass is 1 gram, but may range from 100 mg to 2 grams.
Ion chromatography with detection by conductivity, UV or Pulsed Amperometric Detector (PAD). Calibration is generally external with a minimum of three calibration points.
Limit of Quantitation
The limit of quantitation is dependent on the mass of sample taken for the analysis, the extraction/dissolution volume and the calibration of the instrument. Please contact us to discuss your project needs. Typically, Cornerstone can calibrate to the low ppm for metals in many sample types.
C Metal speciation resources