Standard Operating Procedure for Phytoplankton Analysis ...

Sampling and Analytical Procedures
for GLNPO’s WQS
4.9 Pre-cleaned microscope slides, 25 x 75 mm
4.10 Syringe, 20-mL with cannula, 14-gauge 4-inch
4.11 Long-neck disposable pipettes
4.12 Rubber bulbs for pipettes
4.13 10-mL autopipette
5.0 REAGENTS
5.1 HNO3 = Nitric Acid (concentrated)
5.2 H2O2 = Hydrogen peroxide (30% solution)
5.3 K2Cr2O7 = Potassium dichromate
5.4 Hyrax TM mounting media, or equivalent
5.5 Toluene/xylene
5.6 Commercial formaldehyde solution 37 - 40% (= Formalin)
5.7 ALeitz@ immersion oil
6.0 ANALYTICAL PROCEDURE
6.1 Phytoplankton sample received at the lab shall be logged-in and spiked with 10 ml of Formalin.
6.2 10-mL Preliminary Investigation
6.2.1 An initial screening of each sample must be done in order to determine the final settled volume needed for
analyses unless historical data is available to show what volumes have traditionally been used for samples
from the same site. This is done by sedimenting 10 mL of each sample and counting the total number of
photosynthetic organisms, and the number of diatom cells, within a select area of the slide (10 mm 2
minimum or 3 transects of the chamber). No identifications are done at this time, but any irregularities
such as excessive sediment in the sample are noted.
The volume needed for settling and subsequent soft algae analysis is determined from the number of all
organisms counted. The sample volume to be digested for diatom analysis is determined from the
preliminary diatom cell counts. However, the minimum volume for digestion is recommended to be 500
mL. For example:
10-mL preliminary counts
1) 101 organisms total
2) 103 diatom cells (note: 1 cell has 2 frustules/valves)
Page 2 LG401, Revision 05, February 2010