| MatrixName | MatrixDescr | 
			| air | colorless, odorless, tasteless, gaseous mixture, mainly nitrogen (approximately 78 percent) and oxygen (approximately 21 percent) with lesser amounts of argon, carbon dioxide, hydrogen, neon, helium, and other gases | 
			| benthic | Flora and fauna collected from the bottom of a waterbody | 
			| blankmatrix | matrix free of interferences (e.g, in reagent water, clean sand, or another suitable reference matrix) that is commercially or Lab-produced used for tissue and sediment QA samples | 
			| blankwater | matrix free of interferences (reagent water) that is commercially or Lab-processed used for water QA sample | 
			| blankwater_modified | For use with CNSL toxicity test sample types. Matrix free of interferences (reagent water) that is commercially or Lab-processed used for water QA sample, modified to reflect the salinity or conductivity of a particular sample. | 
			| effluent | Wastewater--treated or untreated--that flows out of a treatment plant, sewer, or industrial outfall | 
			| Extract_AlgalMat | Algal mat sample digested/extracted by laboratory procedure | 
			| Extract_Samplewater | Samplewater extracted from sorbent media or solid phase extraction | 
			| groundwater | The supply of fresh water found beneath the Earth's surface, usually in aquifers, which supply wells and springs | 
			| habitat | habitat at the location | 
			| labwater | unprocessed laboratory tap water | 
			| Not Applicable | not applicable | 
			| not recorded | not recorded | 
			| overlyingwater | the water above the sediment surface within a test container, used for toxicity | 
			| PBSwater | Phosphate buffered saline | 
			| PCRmatrix | Used for QC samples in PCR analyses. PCR reagents without the addition of sample DNA or a positive standard. May contain PCR Extraction Blank. | 
			| recycledwater | Water which, as a result of treatment of waste, is suitable for a direct beneficial use or a controlled use that would not otherwise occur and is therefore considered a valuable resource (WC§13050n). | 
			| referencetoxicant | metal or chlorinated organic used to evaluate the health and sensitivity of test organisms over time and assessing laboratory performance | 
			| runoff | That part of precipitation, snow melt, or irrigation water that runs off the land into streams or other surface-water. Water sampled prior to mixing with ambient surface water. | 
			| samplewater | Ambient surface water collected in the field | 
			| samplewater, <1.2 um | Samplewater filtered through <1.2 um | 
			| samplewater, <125 um | Samplewater filtered through <125 um | 
			| samplewater, <200 um | Samplewater filtered through <200 um | 
			| samplewater, <35 um | Samplewater filtered through <35 um | 
			| samplewater, <5 um | Samplewater filtered through <5 um | 
			| samplewater, particulate, <177 um | Particulate from samplewater filtered through <177 um | 
			| samplewater, particulate, <63 um | Particulate from samplewater filtered through <63 um | 
			| samplewater, particulate, >200 um | Particulate from samplewater filtered through >200 um | 
			| samplewater, particulate, 1.2 to <5 um | Particulate from samplewater filtered through 1.2 to <5 um | 
			| samplewater, particulate, 125 to <200 um | Particulate from samplewater filtered through 125 to <200 um | 
			| samplewater, particulate, 35 to <125 um | Particulate from samplewater filtered through 35 to <125 um | 
			| samplewater, particulate, 5 to <35 um | Particulate from samplewater filtered through 5 to <35 um | 
			| samplewater, particulate, 63 um to 2000 um | Particulate from samplewater filtered through 63 um to 2000 um | 
			| sediment | Loose particles of sand, clay, silt, and other substances that settle at the bottom of a water body | 
			| sediment, <63 um | Sediment sample sieved through <63 um | 
			| sediment, 63 to 2000 um | Sediment sample sieved through 63 to 2000 um | 
			| sediment, elutriate | Sediment, elutriate - Non-contaminated water mixed with sediment and allowed to settle prior to analysis of the water portion | 
			| sediment, interstitialwater | water occupying the spaces between sediment particles- same as pore water - may or may not be centrifuged | 
			| sedimentsuspended | Sediment sample isolated from large volumes of water by centrifuging | 
			| SEM-Extract | Extract derived from the Simultaneously Extracted Metals procedure, analyzed for individual metal concentrations. | 
			| tissue | Part of an organism consisting of an aggregate of cells having similar function; muscle, nerve epidermal or connective | 
			| unknown | matrix is not known |