News
04-May-2006 - LGC sets the standards for metal extraction
analysis
Introducing a new reference material for characterising
extractable metals in soils and sediments
Environmental laboratories extracting metals from soils and
sediments using the ISO11466:1995 protocol can now monitor the
reliability and reproducibility of their results thanks to a new
reference material available through LGC Promochem.
LGC6189 River Sediment has been specifically developed by LGC to
aid comparisons of metal extraction results between laboratories,
something traditionally very difficult to do because most
laboratories vary the time, temperature and acid combinations of
the ISO11466:1995 protocol according to their own preferences.
Until now, there have been no standards against which laboratories
can check their results for bias or monitor the ongoing performance
of their metal extraction procedure, as available materials were
not specific to the exact method conditions.
To address this, LGC has characterised the new reference material
by extracting using the exact conditions specified in the ISO
protocol, and measuring the concentration of those metals that
reached stable 'extraction plateaus' of concentration after the
specified two hour reflux time. Measurement of the dissolved metal
concentrations was carried out using inductively coupled plasma
mass spectrometry (ICP-MS). A single primary standard, closely
matched to the analyte concentration in the sample, was used to
calibrate the procedure.
Once a laboratory has established the relationship between results
obtained using its own metal extraction conditions and those
obtained using the exact ISO procedure, the new LGC6189 reference
material can then be used to monitor the ongoing performance of the
laboratory’s protocol to ensure consistency and
reproducibility.
LGC6189 is packaged in 30g units in screw-capped amber glass
bottles. It comes with assessed values, with associated
uncertainty, for arsenic, cadmium, chromium, copper, manganese,
molybdenum, nickel, lead and zinc, as well as an indication of the
mineral composition of the sediment.
For further information about LGC6189 River Sediment and related
reference materials for extractable metals, please contact LGC
Promochem by email at askus@lgcpromochem.com.
Notes to Editors