Current through August 26, 2024
The purpose of this section is to establish minimum
requirements that can significantly affect data quality but are not always
clearly or consistently addressed in all approved methods.
Note: The Department will take the
applicability of these requirements into consideration when there are new
approved methods or advancements in technology.
(1) OXYGEN DEMAND ASSAYS (BOD or CBOD).
(a) The environmental conditions for the
analysis of biochemical oxygen demand and carbonaceous biochemical oxygen
demand shall be 17 to 23 °C.
(b)
When dissolved oxygen meters are calibrated using a water-saturated air or
air-saturated water standard, the laboratory shall verify concentrations in
mg/L of those standards by comparing those concentrations to the dissolved
oxygen theoretical saturation point. The measured concentration shall be at or
near the theoretical saturation point.
(c) The laboratory shall use the theoretical
saturation point, based on temperature and barometric pressure, on each day of
analysis to assess supersaturation.
Note: When barometric pressure and temperature
measurement features are available on the DO meter, they should be taken from
the DO meter
(d) The
laboratory shall properly treat supersaturated samples before an initial
dissolved oxygen measurement is performed.
(e) When the laboratory uses pipets to
deliver sample volumes, the tips shall be manufactured to be
wide-bore.
(f) When the laboratory
analyzes multiple method blanks and glucose-glutamic acid standards in an
analytical batch, each method blank and glucose-glutamic acid standard analyzed
shall be assessed individually and associated to the entire analytical batch
unless individual method blanks and individual glucose-glutamic acid standards
are clearly documented to be traceable to specific groups of 20
samples.
(g) The laboratory shall
seed disinfected samples and nitrogenous demand inhibited samples.
(h) The laboratory may not add nitrogenous
demand inhibitor to the glucose-glutamic acid standard, to seed material, or
method blanks.
(i) The laboratory
shall use sample volumes for dilutions that are sufficient to expect 2 mg/L
depletion in at least one dilution.
(j) When equipment with multiple dissolved
oxygen probes is employed, the laboratory shall calibrate each probe. Sample
records shall be traceable to the probe used.
(k) The laboratory shall calibrate dissolved
oxygen probes on each day of use.
(l) The laboratory shall use local barometric
pressure which has not been adjusted to sea level.
(m) When determining residual chlorine, a
minimum detection capability of 0.1 mg/L shall be met.
(2) COLORIMETRIC OR TURBIDMETRIC.
(a) Except for inverse chemistries, the
laboratory shall use calibration blanks in the initial calibration of
colorimetric or turbidimetric analyses, and those calibration blanks shall be
assigned the measured response.
Note: High range chemical oxygen demand and
hexavalent chromium are two tests where inverse chemistries are
utilized.
(b) When closed
vials are digested using block digesters for total phosphorus, the laboratory
shall perform the digestion at 150 ± 2 °C for a minimum of 30
minutes.
(c) When the laboratory
uses sulfide strips, the sulfide strips shall have a minimum detection
capability of 10 mg/L.
(d) The
laboratory may not dilute samples after the color reagent has been added to the
samples.
(e) The laboratory shall
process hexavalent chromium standards the same as samples.
(3) ELECTROMETRIC ASSAYS (I.E. ION-SELECTIVE
ELECTRODE). When the laboratory performs electrometric assays, the laboratory
shall perform an initial calibration on each day of analysis.
(4) GRAVIMETRIC ASSAYS - RESIDUE (SOLIDS).
(a) The laboratory may not use Buchner
funnels or Gooch crucibles for determination of total suspended solids or total
dissolved solids.
(b) When the
laboratory uses pipets to deliver sample volumes for total solids and total
suspended solids, the pipet tips shall be manufactured to be
wide-bore.
(5)
GRAVIMETRIC ASSAYS - OIL & GREASE AS HEXANE EXTRACTABLE MATERIALS (HEM).
(a) When using the solid phase extraction
technique, the laboratory may not allow polar solvents to contact the sample.
(b) The laboratory shall use
activated silica gel for silica gel-treated determinations.
(6) TITRIMETRIC OR POTENTIOMETRIC TITRATION
ASSAYS. When standardization is required by method, the laboratory shall
standardize all titrants monthly, unless all the following are met:
(a) Unused titrant is never poured back into
the original container.
(b)
Titrants shall always be protected from light.
(c) LCS recovery control limits shall be set
at 90 to 110%, or tighter, and recovery is achieved.
(7) NONDISPERSIVE IR OR MICROCOULOMETRY.
(a) For total organic carbon determinations,
the laboratory shall perform an inorganic carbon removal check with each
analysis batch.
(b) For aqueous
samples with results greater than or equal to the LOQ, the laboratory shall
perform duplicate injections until the relative percent difference is 10% or
less.
(8) ION
CHROMATOGRAPHY (IC). The width of the retention time window that the laboratory
uses to make identifications shall be based upon measurements of actual
retention time variations of standards over the course of a day unless analyst
experience provides for another defensible procedure.
(9) FLAME ATOMIC ABSORPTION SPECTROPHOTOMETRY
(FLAA).
(a) The laboratory shall perform at
least two consecutive readings for all samples, standards, and quality control
samples, and the laboratory shall use the average for calculating
results.
(b) When sample
concentrations are greater than the LOQ, the laboratory shall use a control
limit of 10% or less for the relative percent difference between replicate
aspirations.
(c) The laboratory
shall include the same acid types and concentrations in calibration standards
as those used in samples.
(10) GRAPHITE FURNACE ATOMIC ABSORPTION
SPECTROPHO-TOMETRY (GFAA).
(a) The laboratory
shall use at least two firings for all samples, standards, and quality control
samples.
(b) When sample
concentrations are greater than the LOQ, the laboratory shall use a control
limit of 10% or less for the relative standard deviation of replicate
firings.
(c) When elements are
measured at wavelengths lower than 200 nm, the laboratory shall analyze the
samples with an instrument equipped with Zeeman background correction or
equivalent.
(d) The laboratory
shall include the same acid types and concentrations in calibration standards
as those used in samples.
(11) COLD VAPOR ATOMIC ABSORPTION
SPECTROPHOTOMETRY (CVAA). The laboratory shall ensure that potassium
permanganate is present after the two-hour digestion for Hg, or the sample
shall be redigested using a smaller sample amount until potassium permanganate
remains. Instead, the laboratory could choose to add more potassium
permanganate to the affected samples and method blank and digest for an
additional two hours.
(12)
INDUCTIVELY COUPLED PLASMA EMISSION SPECTROPHOTOMETRY (ICP).
(a) The laboratory shall perform a spectral
interference identification study before performing any sample analysis using
the following single element standards: Ag, Al, As, B, Ba, Be, Ca, Cd, Ce, Co,
Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, SiO2, Sn, Sr, Ti, Tl, V, and Zn.
When other interferences have been identified, the laboratory shall perform
appropriate spectral interference identification studies for those
interferences. The laboratory shall analyze the interfering elements to
identify potential interelement interferences for each mode and wavelength
used. This requirement applies to each instrument used for analysis.
(b) The concentration of single element
standards used in the spectral interference identification study shall be at or
greater than the maximum concentrations encountered in samples.
(c) At the beginning of each analysis day,
the laboratory shall verify that interference corrections and background
corrections are working properly through the analysis of interference check
standards. The interference check standards shall include all the identified
interferences at the maximum concentrations encountered in samples.
(d) Interference correction is only valid to
the concentration tested in the spectral interference identification study.
Samples with interferences present greater than the concentrations tested shall
be reanalyzed at a dilution, or if the instrument is capable, the laboratory
may analyze a single element standard at the level in the sample to demonstrate
that the apparent concentration is less than the LOQ; if it is not less than
the LOQ, the interelement correction factors may be updated, and all of the
associated data can be reprocessed.
(e) When reporting results to the LOD, the
concentration of each non-spiked target element in the interference check
standard shall be less than 10/3 their corresponding LOD.
(f) Adjusting background correction shall
require re-evaluation of any interference corrections that are affected by the
element to which the background correction was made.
(13) INDUCTIVELY COUPLED PLASMA-MASS
SPECTROMETRY (ICP/MS).
(a) Only those masses
listed in methods may be used for identification and quantitation unless the
laboratory has supporting data that identifies the potential interfering
species for the masses used, and the correction equations needed to resolve the
interferences are employed.
(b)
All quality control samples shall be performed on the isotope used for
identification and quantitation.
(14) GAS CHROMATOGRAPHY (GC).
(a) For non-aqueous volatiles analysis, the
laboratory shall ensure that the calibration standards contain the same
preservative type as the samples, such as methanol, sodium bisulfate, and
reagent water.
(b) When the
laboratory analyzes multi-peak compounds, such as aroclors, toxaphene, and
technical chlordane, the laboratory shall document in its standard operating
procedures all the following:
1. For each
compound reported, the process used to determine which peaks are used to
identify and quantitate the compound.
2. For each compound reported, the process
used to determine how the laboratory quantitates the compounds when the
compound exhibits weathering, degradation, or positive interferences.
3. For aroclors, the process used to
determine how the laboratory quantitates each aroclor when more than one
aroclor is present in the sample.
(15) GAS CHROMATOGRAPHY-MASS SPECTROMETRY
(GC/MS).
(a) The laboratory shall meet full
scan tune requirements before selective ion monitoring analysis
begins.
(b) For non-aqueous
samples, the laboratory shall ensure that the calibration standards shall
contain the same preservative type as the samples, such as methanol, sodium
bisulfate, and reagent water.
(16) HAZARDOUS WASTE CHARACTERISTICS.
(a) The laboratory shall stir samples during
pH measurements for toxicity characteristic leaching procedure fluid type
determinations.
(b) The laboratory
shall perform a flashpoint standard suitable for ignitability determinations
for each batch of samples analyzed for flashpoint analysis.
(17) PREPARATORY METHODS.
(a) Unless otherwise required by the method,
the laboratory shall fortify any quality control sample prior to the addition
of the preparation reagents.
(b)
The laboratory shall perform microwave preparations with instruments that
utilize temperature feedback control.
Pursuant to s.
299.11(4) (c), Stats., this chapter is shown as amended
eff. 6-29-21 by CR 17-046.
