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                   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, contact 
                    -  
                  LGC Promochem 
                    Email: [email protected] 
                     
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