Definition of analytical methods, abbreviations, symbols, and formulas

Abbreviations and Symbols
C =
celsius
Fs =
F-pseudosigma - nonparametric statistic for deviation
HCl =
hydrochloric acid
Hg - =
mercury sample
HNO3 =
nitric acid
Lh =
lower hinge value
L =
liter
Lab =
Laboratory
mg/L =
milligrams per liter
mL =
milliliter
M - =
major ion sample
MPV =
most probable value
n =
number of analyses
N =
normality
N - =
nutrient sample
NR =
not rated; less than values reported or insufficient data
OLR =
overall laboratory rating for each sample type
OWR =
overall weighted rating for all sample types
P - =
precipitation sample (low ionic-strength, typically <50 mS/cm)
ppm =
parts per million
SRS =
standard reference sample
T - =
trace sample
Uh =
Upper hinge value
USGS =
United States Geological Survey
V =
number of rated analyses
Z-value =
number of F-pseudosigmas from the MPV
mg/L =
micrograms per liter
mm =
micrometer
mS/cm =
microsiemens per centimeter at 25º Celsius
< =
less than
-- =
not reported
Analytical methods and codes
Code
Method
0
Other
1
Atomic absorption: direct, air
2
Atomic absorption: direct, nitrous oxide
3
Atomic absorption: graphite furnace
4
Inductively coupled plasma
5
Direct current plasma
6
Inductively coupled plasma/mass spectrometry
7
Ion chromatography
8
Atomic absorption: cold vapor
9
Atomic fluorescence
10
Atomic absorption: extraction
11
Atomic absorption: hydride
12
Flame emission
20
Titration: colorimetric
21
Titration: electrometric
22
Colorimetric
40
Ion selective electrode
41
Electrometric [pH and specific conductance]
50
Gravimetric
51
Turbidimetric

Formulas:
MPV = median value (excluding less than values)
F-pseudosigma (Fs) = ( Uh - Lh) / 1.349
Uh = median of the upper half of the reported values (excluding less than values)
Lh = median of the lower half of the reported values (excluding less than values)
Z-value = (reported value - MPV) / F-pseudosigma
OLR = mean of all rated analytes for sample type
OWR = (OLR*V1)+(OLR*V2)...(OLR*Vn)
                             (V1+V2+...+Vn)

Ratings:
Absolute Z-value
Rating
0.00 - 0.50
4 (Excellent)
0.51 - 1.00
3 (Good)
1.01 - 1.50
2 (Satisfactory)
1.51 - 2.00
1 (Marginal)
greater than 2.00
0 (Unsatisfactory)