Methods of analysis for parameters of interest The below stated

Methods of analysis for parameters of interest
The below stated methods were provided with permission and verbatim from the National Laboratory for
Environmental Testing, Environment Canada. Note that these methods may be periodically subject to change.
Standard Method
Dissolved Inorganic
Analysis is conducted for dissolved inorganic and organic carbon using a UV-persulfate
TOC Analyzer (Pheonix 8000). The dissolved inorganic carbon, (DIC), (carbonate,
bicarbonate, and dissolved carbon dioxide) in filtered water samples is measured by
acidifying with phosphoric acid to pH of 3 or lower, and then sparged with a stream of
inert nitrogen gas in the IC sparger. Acidification converts carbonate and bicarbonate to
carbon dioxide, which is then transported along with the dissolved CO 2 by the gas stream.
The gas stream passes through the Gas/Liquid Separator, Mist Trap, Permeation Tube
and finally through the Chlorine Scrubber to remove moisture and chlorine which may
have been produced during the oxidation step. The concentration of CO 2 is measured by
a non-dispersive infrared (NDIR) detector. The detector is sensitive to the absorption
frequency of CO2 and provides a signal proportional to the concentration of CO 2 in the
carrier gas. The detector output signal is linearized and is displayed on the video screen
as a real time strip chart recording. The linearized signal is integrated and referred to
stored calibration data [1]. The dissolved organic carbon, (DOC), is measured by first
removing the inorganic carbon as described above and the liquid at the bottom of the IC
sparger is immediately re-sampled and introduced in the UV reactor chamber. In the
reactor chamber, the sample is mixed with sodium persulphate solution and phosphoric
acid solution, such that the sample is simultaneously exposed to persulphate ions and to
UV radiation, which produce a highly oxidizing condition to convert organic carbon to
CO2. The CO2 produced is then swept by a stream of gas which passes through the Gas/
Liquid Separator, Mist Trap, Permeation Tube, Chlorine Scrubber, and finally through
the NDIR detector.
Analytical Range: concentrations of organic carbon from 0.1 to 10 mg/L and
concentrations of inorganic carbon from 0.2 to 25 mg/L
1. Phoenix 8000 User Manual, Tekmar - Dohrmann, 7143 East Kemper Road,
Cincinnati, Ohio 45242-9576.
Standard Method
Sodium, Potassium
Cations, Filtered, Direct Analysis, Inductively Coupled Plasma-Optical Emission
Spectrometry Method: A whole water sample is filtered through a 0.45 um cellulose
acetate membrane filter. The filtrate is placed in a 100 mL high density polyethylene
bottle. An aliquot of the filtrate is analyzed by an Inductively Coupled Plasma-Optical
Emission Spectrometer (ICP-OES). The sample is introduced as a fine aerosol to the
instrument plasma by pneumatic nebulisation where energy transfer processes causes
desolvation, atomization and ionization. Excitation of the atoms and ions occurs within
the plasma. They will then decay to their lower more stable states and an emission
spectra characteristic of the elements is produced. A diffraction grating is used by the
instrument to disperse the spectra and the intensities of the lines for the elements of
interest are captured by a CCD detector. The emission of radiation is proportional to the
analyte's concentration in the sample. Quantification is achieved by calibration of the
spectrometer with known solutions of analyte(s) standards spread across the analytical
range. Typical line wavelengths include 317.9 nm for Ca, 766.5 nm for K, 285.2 nm for
Mg , 589.6 for Na, and 251.6 nm for silicon (as silica, SiO2). NLET Method 01-1162.
Reference Method: Standard Methods for the Examination of Water and Wastewater,
21st Edition, 3120 B.
Analytical Range: sample concentrations which exceed 100 mg/L for Ca and
Na and 50 mg/L Mg and K require dilution
Si - 0.01 to 21.4 mg/L
Standard Method
Fluoride, Chloride,
Nitrate, Sulphate
A whole water sample is filtered through a 0.45 um cellulose acetate membrane filter.
The analysis of the anions, fluoride, chloride, nitrate and sulphate on an aliquot of the
filtrate is conducted by ion chromatography. This chromatographic separation method is
based on an ion exchange process occurring between the mobile eluent phase and ionexchange group bonded to the support material. The potassium hydroxide, KOH, eluent
is produced electrolytically , in situ, in a Eluent Generator (EG) system based on the
addition of water to a KOH generator cartridge. Any anions, in particular, carbonate
ions, introduced into the system by the deionized water are contaminants, and are
removed by a continuous generating anion trap column (CR-ATC) placed before the
sample injection valve. The water sample is ejected into the eluent stream. It is then
pumped through a guard column and an analytical hydroxide-selective ion exchange
column where the ion separation occurs. The ions of interest are separated based on the
affinity for the exchange sites of the resin bed. The sample is then pumped through the
suppressor which reduces the background conductivity of the eluent to a negligible level,
by removing the KOH from the analytical stream and converting the anions of the sample
to their respective acid forms ( HF, HCl, HNO3, and H2SO4). Any carbonic acid
produced due to the presence of carbonate in the sample, may interfere with analyte
peaks, and is minimized by the use of a Carbonate Removal Device (CRD). The
concentrations of these separated anions are determined by measuring their respective
conductivities using a conductivity detector. Anions are identified chromatographically
by their retention times and quantified by comparing their peak integrations with known
calibration standards.
Analytical Range: normal ranges in precipitation and surface waters; fluoride (0.01 - 3.0
mg/L), chloride (0.01 - 45 mg/L), nitrate (0.005 - 3.0 mg/L) and sulphate ( 0.01- 90
for the excha
Standard Method
Particulate Organic
Carbon / Nitrogen
The volume of water required for filtration to determine the particulate organic carbon
content depends on the type of sample. The following guidelines may be useful:
 If the sample contains 10 mg/L or more of suspended matter, use 500 mL of
water sample.
 Similarly, if there is 5-10 mg/L, 2-5 mg/L or less than 2 mg/L of suspended
matter, use 1 L, 1-2 L or more than 2 L, respectively, of the water sample.
These guidelines are only a rough approximation.
The sample is first oxidized in a pure oxygen environment. The resulting gases are then
controlled to exact conditions of pressure, temperature and volume. Finally, the product
gases are separated under steady-state conditions and are measured as a function of
thermal conductivity. Operating gases include oxygen for combustion of the sample
materials and helium or argon as a carrier gas. Several catalysts are employed to ensure
complete conversion of C, H and N components to CO2, H2O and N2. For instance, when
the PE 2400 CHN analyzer is used, the combustion is performed in the presence of
chromium/nickel oxide to oxidize the carbonaceous material to CO2 and H2O. Any
carbon monoxide formed is oxidized further to CO 2 by passing the gaseous products
through copper and copper oxide.
Particulate inorganic carbon and nitrogen, obtained by filtering the suspended solids, is
dissolved by washing the solid residue with 0.3 % (v/v) sulphuric acid. The dried residue
remaining is particulate organic carbon and nitrogen and is ready for analysis.
Analytical Range: the normal range for carbon is: 0.005 to 1.78 mg, and for nitrogen:
0.002 to 0.26 mg
Standard Method
The water sample is filtered and the residue extracted with acetone for
spectrophotometric determinations at specified wavelengths of 663 nm, 645 nm, and 630
nm. Chlorophyll a, b and c values are calculated using SCOR/UNESCO equations[1].
Analytical Range: 0.1 to 100 µg/ L
UNESCO, Determination of Photosynthetic Pigments in Seawater, 1965.