Glossary - M
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"Macro analysis" means the determination of parameters
at concentrations in the high part per million or percent
"Manual" means "Manual for the Certification
of Laboratories Analyzing Drinking Water, Criteria and Procedures
Quality Assurance," USEPA/570/9-90/008, USEPA, Office
of Water (WH-550D), Washington, DC 20460, as updated or supplemented.
This reference is the federal training and standard operating
procedures manual for federal, state, and local certification
officers of drinking water laboratories for microbiological,
chemical, and radiochemical testing.
"Maximum contaminant level (MCL)" means the maximum
permissible level of a contaminant allowed in drinking water
under the National Primary Drinking Water Regulations.
"Membrane filtration (MF) method" means a method
for determining the bacterial count in a water sample. In
this method, a known volume of water is filtered through a
membrane filter of optimum pore size for full bacterial retention.
The filter is incubated in contact with culture medium to
provide nutrients for bacterial growth. After incubation at
a prescribed time and temperature, the cultures are examined
for bacterial colonies that are counted and recorded per 100
mL of water sample.
"Method detection limit" (MDL) means the minimum
concentration of a substance that can be measured and reported
with 99 percent confidence that the analyte concentration
is greater than zero and is determined from analysis of a
sample in a given matrix type containing the analyte according
to the Guidelines Establishing Test Procedures for the Analysis
of Pollutants, 40 CFR 136, Appendix B.
"Method reference" means the name, abbreviation
or acronym (e.g. USEPA, ASTM, USGS) of the organization that
has developed an approved method or of the publication containing
an approved method. The method reference, together with the
method number, specifically identifies a method.
"Methods for Measuring Acute Toxicity - EPA" means
"Methods for Measuring Acute Toxicity of Effluents to
Aquatic Organisms," USEPA, Environmental Monitoring and
Support Laboratory, Cincinnati, Ohio, EPA-600/4-78-012.
"Micro analysis" means the determination of trace
quantities of parameters at concentrations in the low and
sub part per million range.
"Modified static toxicity test" means, for Acute
Toxicity Testing, the "Renewal Toxicity Test."
"Most probable number (MPN)" means a quantitative
designation of microbial population which is determined by
a statistical method. In this method, a multiple dilution
tube technique is used with a standard culture medium. The
tubes are incubated and observed for gas production. Results
of these tubes are translated by mathematical probability
tables into population numbers.
"MS" means mass spectrometry.
"mv" means millivolt or 1/1000 of a volt.