EPRI Method I2

Liquor collected from in-line filtration (positive pressure);
Sample preservation (dilution) with borate buffer and formaldehyde preservative.
- Weigh sample bottle including label and cap to the nearest 0.01 g and record weight;
- Add about 100 mL borate buffer to bottle;
- Add enough formaldehyde such that there will be about a 5:1 formaldehyde to sulfite molar ratio in the diluted sample to bottle;
- Record the amount of formaldehyde added to each sample bottle
- Reweigh bottle (including cap) to the nearest 0.01 g and record weight;
- Label as "Anion DF with Formaldehyde"
- Color coding bottles (preservatives) can help with later identification.
Sample can also be used for thiosulfate, sulfur-nitrogen, or polythionate analyses if cooled to 4^oC immediately after collection.

The formaldehyde preservation solution should be shipped as a hazardous material. Please call for IATA codes if you need them.
Samples may be shipped at ambient temperatures.
Be sure to include a chain of custody for each shipping container.

This is the only analytical procedure in the EPRI FGD Manual that directly measures sulfate content. Other procedures measure total sulfur as sulfate.
If sulfate and sulfite are the only sulfur species present in significant concentrations, sulfate can be determined using any of the total sulfur methods in the EPRI Handbook in conjunction with sulfite anlaysis.
If other sulfur species are present (e.g. thiosilfate, sulfur-nitrogen compounds, or polythionates), this is the method of choice.
Can be used to quantify a number of different anions in liquid samples from FGD system provided that high molar ratios of certain species in the samples do not prevent adequate resolution of the peaks of interest.