TITLE: USDA LTAR Common Experiment measurement: Total suspended solids (TSS)
AUTHORS: Brent Dalzell, Oliva Pisani

[DESCRIPTION]
Total suspended solids (TSS) refers to all the material from a well-mixed sample retained by a filter media. In the case of environmental water samples, TSS is commonly used to measure sediment in surface waters (field runoff, ditches, and streams) but can also be present in subsurface flow where macropore flow or surface inlets to tile drainage systems are present. In some cases, TSS can also include algae or other plant materials that comprise volatile suspended solids (VSS) because combustion in a muffle furnace eliminates them. The recommended method for measuring TSS includes passing a known sample volume through a pre-weighed filter and measuring the oven-dry weight of the material trapped on the filter.

[STEPS]
SECTION: Sample collection
1. At a minimum, collect 1 mg of TSS residue. At a maximum, TSS should not impede the flow rate of the filter media (slow filtration is more time-consuming but does not impact results). 

 

SECTION: Sample collection
2. Return samples to the laboratory on ice and filter them on collection day if possible.

SECTION: Sample storage and preservation
3. Analyze the samples as soon as possible after collection. 
SECTION: Sample storage and preservation
4. If storage is required, refrigerate the samples at 4 °C or store on ice to minimize decomposition of solids.

 

SECTION: Archiving
5. Store water samples for TSS analyses until data certification (QA/QC verification) as this is common practice. 

 

SECTION: Glass fiber filter preparation
6. Assemble the vacuum filtration apparatus with a new filter.
SECTION: Glass fiber filter preparation
7. Apply the vacuum. 
SECTION: Glass fiber filter preparation
8. Rinse the filter three times with distilled water. 
SECTION: Glass fiber filter preparation
9. Maintain the vacuum for a few seconds to remove excess water, then remove the vacuum.
SECTION: Glass fiber filter preparation
10. Using forceps, carefully remove the rinsed filter to an aluminum weighing dish. 
SECTION: Glass fiber filter preparation
11. Dry in an oven at 103 °C - 105 °C for 1 hour. 

SECTION: Glass fiber filter preparation
12. Store dried filters in a desiccator until needed. 
SECTION: Sample analysis
13. Using forceps, select a prepared glass fiber filter. Weigh it and record the mass to the nearest 0.1 mg in a lab notebook.
SECTION: Sample analysis
14. Unless filtering the entire sample, shake it vigorously before dividing it into a volume suitable for analysis.
SECTION: Sample analysis
15. Select a water sample, weigh the sample + bottle mass, and record the mass in a lab notebook.
SECTION: Sample analysis
16. Assemble the filtration apparatus and apply a vacuum.
SECTION: Sample analysis
17. Pre-moisten the filter with a small volume of distilled water.
SECTION: Sample analysis
18. Shake the sample vigorously and pour it into the filtration apparatus funnel.
SECTION: Sample analysis
19. Maintain the vacuum until all sample water has passed through the filter.
SECTION: Sample analysis
20. Using a wash bottle with distilled water, rinse the sample bottle and sides of the filter funnel three times (for a 4.7 cm filter, each rinse should be roughly 10 ml).
SECTION: Sample analysis
21. Weigh the empty sample bottle and record the mass in a lab notebook. 
SECTION: Sample analysis
22. Remove the vacuum.
SECTION: Sample analysis
23. Using forceps, carefully remove the filter paper and place it in a labeled and weighed aluminum weighing dish.
SECTION: Sample analysis
24. Dry the filter paper + sample at 105 °C for 1 hour or longer, if necessary, to remove all water.

SECTION: Sample analysis
25. Remove the samples from the oven and immediately store them in a desiccator or weigh them. Record the mass in a lab notebook.
SECTION: Sample analysis
26. Store the weighed and recorded filters in a desiccator until ready for disposal. 
SECTION: Sample analysis
27. Sample the covariate metrics (Total N (TN) and total P (TP) concentrations) concurrently.
SECTION: Sample analysis
28. Perform the calculations using the following formula: 
Total suspended solids in a sample (mg/L) = (A-B) * 1000 / C

 

SECTION: Recommendations for data collection
29. Table 1. Summary of recommendations for the collection and measurement of TSS concentration.