FIL - Filtered (in the past known as dissolved (DIS)), Pertains to the constituents
in a representative water sample that pass through a 0.45-micrometer membrane filter for inorganic analysis or a
0.7-micrometer glass fiber filter for organic analysis. This is a convenient operational definition used by Federal agencies
that collect water data. Determinations of "dissolved" constituents are made on sub-samples of the filtrate.
| G C - Gas chromatography |
| G C / E C D - Gas chromatography/electron capture detector |
| G C / F I D - Gas chromatography/flame ionization detector |
| G C/ F P D - Gas chromatography/flame photometric detector |
| G C / M S - Gas chromatography/Mass Spectrometry |
| G C / M S / S I M - Gas chromatography/Mass Spectrometry/selected ion monitoring |
| G C / N P D - Gas chromatography/Nitrogen Phosphorous detector |
| H P L C - High-performance liquid chromatography |
| Information-rich methods - Classified as organic methods
that use either mass spectrometric or photodiode array ultraviolet/visible
spectroscopic detection. These methods have additional qualifying information that allows enhanced analyte
identification. |
| IRL - Interim Reporting Level |
| L C - Lab Code |
| L T - M D L - Long Term Method Detection Level - A detection level
derived by determining the standard deviation of a minimum of 24 MDL spike sample measurements over an extended period
of time. LT-MDL data are collected on a continuous basis to assess year-to-year variations in the LT-MDL.
The LT-MDL controls false positive error. The chance of falsely reporting a concentration at
or greater than the LT-MDL for a sample that did not contain the analyte is predicted to be less than or equal to 1
percent. |
| L M S - Laboratory Matrix Spike - Environmental sample fortified in the lab with known concentrations of
organic compounds |
| L R L - Laboratory Reporting Level - Generally equal to
twice the yearly determined L T - M D L. The LRL controls false negative
error. The probability of falsely reporting a non-detection for a
sample that contained an analyte at a concentration equal to or greater
that the LRL is predicted to be less than or equal to 1 percent.
The value of the LRL will be reported with a "less than" remark code for
samples in which the analyte was not detected. The National Water
Quality Laboratory collects quality-control data from selected analytical
methods on a continuing basis to determine long-term method detection levels
(LT-MDL's) and establish laboratory reporting levels (LRL's). These
values are re-evaluated annually based on the most current quality-control
data and may, therefore, change. [Note: In several previous NWQL
documents (Connor and others, 1998; NWQL Technical Memorandum 98.07, 1998), the LRL was called the
non-detection value or NDV - a term that is no longer used.] |
| L R B - Laboratory Reagent Blank (also known as a set blank)
- Sample of organic-free matrix undergoing the sample preparation steps in the lab |
| L R S - Laboratory Reagent Spike (also known as a set spike) -
Sample of organic-free matrix undergoing the sample preparation steps in the lab |
| L S - Laboratory Schedule |
| L S D - Least Significant Digit - The first real number (nonzero) to the right of
the decimal point in the standard deviation of the LT-MDL spike samples. |
| M D L - Method detection limit - Minimum concentration of a substance that can be
measured and reported with 99-percent confidence that the analyte concentration is greater than zero.
It is determined from the analysis of a sample in a given matrix containing the analyte (U.S. Environmental Protection
Agency, 1997). At the MDL concentration, the risk of a false positive is predicted to be less than or equal
to 1 percent. |
| m g / L - milligram per liter |
| Method Blank Sample of organic-free matrix undergoing the sample preparation steps in the lab |
| M R L - Minimum reporting level - Smallest measured concentration of a constituent
that may be reliably reported by using a given analytical method (Timme, 1995). |
| N A - Not applicable. |
| N A W Q A - National Water-Quality Assessment Program. |
| Non-quantitative result - Unable to report a concentration.
Either not detected or detected in a region of high uncertainty (high probability of false positive) and outside the
calibration range. |
| N W Q L - National Water Quality Laboratory |
| O B S P - Organic Blind Sample Project |
| P C B - Polychlorinated Biphenyls |
| P C N - Polychlorinated Naphthalene |
| Quantitative result - Concentration reported.
Value is within range of instrument calibration and, thus, of higher certainty. |
| Reagent Blank (also known as a set blank) - Sample of organic-free matrix undergoing the sample
preparation steps in the lab |
| Reagent Spike (also known as a set spike) - Sample of organic-free matrix fortified in the lab with known
concentrations of organic compounds |
| Replicate Sample - Environmental sample split into tow or more aliquots |
| R L - Reporting level - A generic term for LRL, MRL, or IRL |
| Semi-quantitative result - Estimated concentration reported because it is outside
the calibration range. |
| S P E - Solid phase extraction |
| S R M - Standard Reference Material |
S R S - Standard Reference Sample - A sample that is prepared to check and monitor inorganic
| Surrogate compounds - Organic compounds similar in physical and chemical properties
to analytes but not present in samples |
| T C E - trichloroethene |
| T H M - trihalomethane |
| T P C - Third Party Check: A standard solution used in instrumental analyses to verify
the identities and quantities of the target compounds in a calibration standard. A TPC standard is typically acquired from a different source
(if possible) than that used to prepare the calibration standard solutions. TPC standards are usually analyzed when an instrument is recalibrated.
If results of the TPC analysis fail to meet the acceptance criteria, then the calibration and TPC standards are further evaluated to determine whether
new standards should be prepared, or other corrective action is necessary. |
| T O T - Total |
| u g / L - microgram per liter |
| U S G S - U.S. Geological Survey |
| V O C - Volatile Organic Compound |
| V O I - Volatile on Ignition |
| W W R - Whole water, recoverable. |
| W Y - Water Year |
|
U.S. Department of the Interior |
U.S. Geological Survey