The Baseline - Mining and the Environment: From Ore to Metal - page 378

TABLE 8.7
Laboratory Considerations (Minnesota Pollution Control Agency 2003)

Bottles and preservatives Ask if the laboratory will provide appropriate bottle types with preservatives.

Cost Consider cost not only of the sample analyses, but also of shipping. Inform the laboratory of the number of samples anticipated. Better unit prices are
usually available for large orders.

Certifi cation In countries where laboratories can be certifi ed, request evidence of certifi cation for the particular tests to be conducted.

Chain of custody Request a description of their chain of custody procedures and copies of their chain of custody forms.

Consistency If you have a long-term project, consider a laboratory you expect will survive for the length of the project. Staying with the same laboratory
for the duration of the project will help minimize variability between laboratories/analysts.

Delivery and shipping Inquire about the delivery service and whether or not this cost is included in the cost per sample analysis. Some labs allow sample
drop-off to satellite locations, which avoids shipping costs.

Detection limits Make sure that the laboratory can achieve the detection limits you need for your project. Ask if they have the necessary equipment to
achieve these limits.

Hours of operation Make sure the laboratory will be able to receive samples at the times you anticipate collecting and be able to complete analyses
within specifi ed holding times.

Methods Specify the methods you want used. Ask if the laboratory has experience with these methods and if they have Standard Operating Procedures
already prepared for these methods. If so, you may want to ask for copies.

QA/QC Ask for a copy of the laboratory's Quality Assurance/Quality Control Manual. Check to make sure that the laboratory's data quality objectives are
consistent with your project objectives and needs.

Reporting Suggest the format for the reported results (i.e. paper report, electronic). Ask them to include results of laboratory QA/QC efforts for precision
and accuracy and to note if data quality objectives were met in the reports. Direct data transfer from the laboratory reports into the mining project data-
base is preferred as it avoids the risk of transcription errors.

Data quality and performance characteristics of methods for analytical chemistry are
typically validated through the use of quality control samples including blanks, calibration
standards, and samples spiked with a known quantity of the analyte of interest. Such QA/
QC procedures are not normally applied to biological laboratory determinations which are
therefore more subjective. Table 8.8 summarizes some performance characteristics used in
analytical chemistry and how these might be applied to biological methods.
Most mining projects maintain their own metallurgical laboratory, used for routine
assays and process research. This laboratory is usually situated within the general vicin-
ity of the mill and processing plant. Some projects also maintain laboratories for analysis
of samples from exploration programmes, which may be combined with the metallurgi-
cal laboratory. Some mining operations operate an environmental laboratory to carry out
water quality testing, avoiding the need to send samples to an offsite laboratory ( Case 8.9) .
It is essential that such an environmental laboratory be located well away from the metal-
lurgical and/or exploration laboratories, and also well away from the mill/process plant
area. This is because environmental laboratories usually need to measure metal concentra-
tions to very low levels (parts per billion); metallurgical laboratories deal with metal con-
centrations in percentage levels. Cross-contamination would be extremely difi cult to avoid
if the laboratories were situated in close proximity. This applies not only to project labo-
ratories, but to contract laboratories that carry out both environmental and exploration/
metallurgical analyses.

Environmental laboratories
usually need to measure metal
concentrations to very low levels
(parts per billion); metallurgical
laboratories deal with metal
concentrations in percentage
levels.