This method is used for the determination of formaldehyde from stationary sources using high purity water and the modified pararosaniline method. Formaldehyde reacts with the acidic pararosaniline and sodium sulfite forming a purple chromophore. The intensity of the chromophore, which is related to the formaldehyde concentration, is measured spectrophotometrically.
Samples are collected isokinetically using a modified Method 5 train which consists of a heated probe and a series of 4 impingers. 100mL of high purity water is added to the first two impingers (200mL of water may be added if high concentrations of formaldehyde are expected or an additional impinger may be added.) The third impinger is empty and the fourth impinger contains 200-300g of silica gel. The recommended sample collection volume is 30 cubic feet for stack concentrations of formaldehyde less than 23,000,000ppbv.
After sample collection, the probe and first three impingers are rinsed with high purity water. Use less than 400mL total and less than 250mL if possible. The rinses including any particulate matter and contents of the first three impingers are combined together and sent to the laboratory for analysis. Note that if breakthrough is to be determined then the contents of the first two impingers and rinses must be kept in separate containers as the laboratory will need to analyze the contents of each separately.
The method requires collection of a field blank. Per the method, the field blank results are used to correct the results of the field samples.
No Obligation Quotation for Analytical Services
If you would like us to provide a quote for laboratory analysis, just provide us with as much information as you can about your project (the more, the better) and we'll provide you a quote via email. As you are searching or browsing our Analytical Guide, you'll see the Request-A-Quote icon... just click on it to start the request process.
| Hold Times, Preservatives, Preps, Collection, Analytical & Documentation | |
|---|---|
| Holding Time: | 14 days from sample collection to analysis |
| Preservatives: | Keep sample iced at 2°C from time of collection until analysis. |
| Required Preps: | Water for impingers. |
| Collection Method: | Modified Method 5 train following EPA Method 316 procedures. |
| Analytical Methodology: | Spectrophotometry |
| Documentation: | 
316
|
| Analyte | Formula | CAS Number | Detection Limit | |
|---|---|---|---|---|
| Formaldehyde | CH2O |
50-00-0 |
11.3 |
ppbv |
* The analytes and detection limits listed for each method represent the typical detection limits and analytes reported for that particular method. Keep in mind that analyte lists may vary from laboratory to laboratory. Detection limits may also vary from lab to lab and are dependent upon the sample size, matrix, and any interferences that may be present in the sample.