Metals Department Overview

Galbraith’s Metals Department employs a range of instrumental methods to digest and then measure Group I Metals, Group II Metals, Transition Metals, Metalloids (such as boron, silicon, germanium, etc.) and some Non-Metal elements (such as sulfur and iodine) in a wide variety of sample matrices.
Each successful analysis begins with sufficiently preparing (digesting) the sample for the analysis.  The final outcome of each preparation is to afford a homogenous solution of the analyte in the analysis solvent.  In most cases, the analysis solvent is water, though organic solvents may occasionally be used. For more information on our preparation for metals analysis, please click here.

 

Once the sample is prepared, the solution will be analyzed by an instrument for the target metal(s).  Galbraith offers testing by the following general techniques:

 

Inductively Coupled Plasma – Atomic Emission Spectroscopy (ICP-AES) also known as Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES).  This technique measures element-specific emission spectra by spectrophotometry.  Sample solutions are nebulized into an aerosol that is transported to a plasma torch.  Metal ions in the sample solution are subjected to intense heat in a radio-frequency inductively coupled argon plasma.  The elements emit characteristic spectra which are separated by a grating.  The intensity of the emission lines are monitored by photosensitive devices.  Metal ion concentrations of unknown samples are determined by comparison to an external calibration of the instrument.  The concentration of the metal(s) in the sample is typically expressed in terms of the original mass taken for the analysis (wt/wt).

 

Inductively Coupled Plasma – Mass Spectrometry (ICP-MS).  This technique measures elements on the basis of their mass to charge ratio.  Sample solutions are nebulized into an aerosol that is transported to a plasma torch.  Metal ions in the sample solution are subjected to intense heat in a radio-frequency inductively coupled argon plasma.  The ions are transported from the plasma through a vacuum interface into a quadrupole where they are separated on their mass to charge ratio (m/z).  Metal ion concentrations of unknown samples are determined by comparison to an external calibration of the instrument.  The concentration of the metal(s) in the sample is typically expressed in terms of the original mass taken for the analysis (wt/wt).

 

Cold Vapor Atomic Absorption (CVAA) (Mercury Only) – This technique relies on absorption of gaseous mercury to absorb energy from a source lamp.  The amount of absorbed energy is proportional to the concentration of mercury in the sample.  Metal ion concentrations of unknown samples are determined by comparison to an external calibration of the instrument.  The concentration of the metal(s) in the sample is typically expressed in terms of the original mass taken for the analysis (wt/wt).

 

Flame Atomic Absorbance (FAA) – This technique relies on aspirating a sample and atomizing it in a flame.  A light beam from a lamp is directed through the flame and into a monochoromator which focuses the detector on the wavelength of maximum absorption of the element.  The amount of light absorbed by the flame is inversely proportional to the amount of that element in the sample.  Metal ion concentrations of unknown samples are determined by comparison to an external or internal calibration (method of standard addition) of the instrument.  The concentration of the metal(s) in the sample is typically expressed in terms of the original mass taken for the analysis (wt/wt).

 

Graphite Furnace Atomic Absorbance (GFAA) – This technique is similar to FAA in that it relies on atomic absorption to measure metal concentrations, but it differs in that it uses a furnace to atomize the sample, not a flame.  This technique offers the advantage of greater atomization of the sample, which affords either a lower detection limits (than conventional FAA) or the use of less sample.  Metal ion concentrations of unknown samples are determined by comparison to an external or internal calibration (method of standard addition) of the instrument.  The concentration of the metal(s) in the sample is typically expressed in terms of the original mass taken for the analysis (wt/wt).