| Term | Definition |
| Ag | Expressed as silver |
| Al | Expressed as aluminium |
| As | Expressed as arsenic |
| B | Expressed as boron |
| Ba | Expressed as barium |
| Be | Expressed as beryllium |
| Br | Expressed as bromine |
| C | Expressed as carbon |
| C10H10O4 | Expressed as dimethyl terephthalate |
| C10H4(CH3)4 | Expressed as tetramethylnaphthalene |
| C10H5(CH3)3 | Expressed as trimethylnaphthalene |
| C10H6(CH3)2 | Expressed as dimethylnaphthalene |
| C10H7C2H5 | Expressed as ethylnaphthalene |
| C10H7CH3 | Expressed as methylnaphthalene |
| C10H8 | Expressed as naphthalene |
| C12H10 | Expressed as C12H10, e.g., acenaphthene, biphenyl |
| C12H14O4 | Expressed as diethyl phthalate |
| C12H8 | Expressed as acenaphthylene |
| C12H8O | Expressed as dibenzofuran |
| C12H8S | Expressed as dibenzothiophene |
| C12H9N | Expressed as carbazole |
| C13H10 | Expressed as fluorene |
| C13H10S | Expressed as methyldibenzothiophene |
| C14H10 | Expressed as phenanthrene |
| C14H12 | Expressed as methylfluorene |
| C15H12 | Expressed as C15H12, e.g., methylphenanthrene, Methylanthracene |
| C15H32 | Expressed as C15 n-alkane |
| C16H10 | Expressed as C16H10, e.g., fluoranthene, pyrene |
| C16H14 | Expressed as dimethylphenanthrene |
| C16H34 | Expressed as C16 n-alkane |
| C17H12 | Expressed as C17H12, e.g., benzo(a)fluorene, methylfluoranthene, methylpyrene |
| C17H36 | Expressed as C17 n-alkane |
| C18H12 | Expressed as C18H12, e.g., benz(a)anthracene, chrysene, triphenylene |
| C18H18 | Expressed as retene |
| C18H38 | Expressed as C18 n-alkane |
| C19H14 | Expressed as methylchrysene |
| C19H20O4 | Expressed as benzyl butyl pththalate |
| C19H40 | Expressed as C19 n-alkane |
| C20H12 | Expressed as C20H12, e.g., benzo(b)fluoranthene, benzo(e)pyrene, perylene |
| C20H42 | Expressed as C20 n-alkane |
| C21H44 | Expressed as C21 n-alkane |
| C22H14 | Expressed as Dibenz(a,h)anthracene |
| C22H46 | Expressed as C22 n-alkane |
| C23H48 | Expressed as C23 n-alkane |
| C24H50 | Expressed as C24 n-alkane |
| C25H52 | Expressed as C25 n-alkane |
| C26H54 | Expressed as C26 n-alkane |
| C27H56 | Expressed as C27 n-alkane |
| C28H58 | Expressed as C28 n-alkane |
| C29H60 | Expressed as C29 n-alkane |
| C2Cl4 | Expressed as tetrachloroethylene |
| C2Cl6 | Expressed as hexachloroethane |
| C2H2Cl4 | Expressed as tetrachloroethane |
| C2H3Cl | Expressed as vinyl chloride |
| C2H3Cl3 | Expressed as trichloroethane |
| C2H4Cl2 | Expressed as dichloroethane |
| C2H5Cl | Expressed as chloroethane |
| C2H6 | Expressed as ethane |
| C2H6O2 | Expressed as Ethylene glycol |
| C2HCl3 | Expressed as trichloroethylene |
| C31H64 | Expressed as C31 n-alkane |
| C3H6O | Expressed as acetone |
| C4Cl6 | Expressed as hexchlorobutadiene |
| C4H8Cl2O | Expressed as bis(chloroethyl) ether |
| C4H8O | Expressed as butanone |
| C5Cl6 | Expressed as hexachlorocyclopentadiene |
| C6Cl6 | Expressed as hexachlorobenzene |
| C6H3Cl3 | Expressed as trichlorobenzene |
| C6H4(CH3)2 | Expressed as xylenes |
| C6H4Cl2 | Expressed as dichlorobenzene |
| C6H4N2O5 | Expressed as dinitrophenol |
| C6H5Cl | Expressed as chlorobenzene |
| C6H5NH2 | Expressed as aniline |
| C6H5NO2 | Expressed as nitrobenzene |
| C6H5OH | Expressed as phenol |
| C6H6 | Expressed as benzene |
| C6HCl5O | Expressed as pentachlorophenol |
| C7H6N2O4 | Expressed as dinitrotoluene |
| C7H8 | Expressed as Toluene |
| C8H10 | Expressed as ethylbenzene |
| C8H8 | Expressed as styrene |
| C9H14O | Expressed as isophorone |
| Ca | Expressed as calcium |
| CaCO3 | Expressed as calcium carbonate |
| Cd | Expressed as cadmium |
| CH2Cl2 | Expressed as dichloromethane |
| CH3Br | Expressed as bromomethane |
| CH3Cl | Expressed as chloromethane |
| CH3Hg | Expressed at methylmercury |
| CH4 | Expressed as methane |
| CHBr2Cl | Expressed as dibromochloromethane |
| CHBr3 | Expressed as bromoform |
| CHBrCl2 | Expressed as bromodichloromethane |
| CHCl3 | Expressed as chloroform |
| Chlorophyll a | Expressed as chlorophyll a |
| Cl | Expressed as chlorine |
| CN- | Expressed as cyanide |
| Co | Expressed as cobalt |
| CO2 | Expressed as carbon dioxide |
| CO3 | Expressed as carbonate |
| Cr | Expressed as chromium |
| Cu | Expressed as copper |
| delta 2H | Expressed as deuterium |
| delta N15 | Expressed as nitrogen-15 |
| delta O18 | Expressed as oxygen-18 |
| EC | Expressed as electrical conductivity |
| F | Expressed as fluorine |
| Fe | Expressed as iron |
| H2O | Expressed as water |
| HCO3 | Expressed as hydrogen carbonate |
| Hg | Expressed as mercury |
| K | Expressed as potassium |
| Mg | Expressed as magnesium |
| Mn | Expressed as manganese |
| Mo | Expressed as molybdenum |
| N | Expressed as nitrogen |
| Na | Expressed as sodium |
| NH4 | Expressed as ammonium |
| Ni | Expressed as nickel |
| NO2 | Expressed as nitrite |
| NO3 | Expressed as nitrate |
| Not Applicable | Speciation is not applicable |
| O2 | Expressed as oxygen (O2) |
| P | Expressed as phosphorus |
| Pb | Expressed as lead |
| pH | Expressed as pH |
| PO4 | Expressed as phosphate |
| QSE | Expressed as quinine sulfate equivalents |
| Ra | Expressed as Radium. Also known as "radium equivalent." The radium equivalent concept allows a single index or number to describe the gamma output from different mixtures of uranium (i.e., radium), thorium, and 40K in a material. |
| Re | Expressed as rhenium |
| S | Expressed as Sulfur |
| Sb | Expressed as antimony |
| Se | Expressed as selenium |
| Si | Expressed as silicon |
| SiO2 | Expressed as silicate |
| Sn | Expressed as tin |
| SO4 | Expressed as Sulfate |
| Sr | Expressed as strontium |
| TA | Expressed as total alkalinity |
| Th | Expressed as thorium |
| Ti | Expressed as titanium |
| Tl | Expressed as thallium |
| U | Expressed as uranium |
| Unknown | Speciation is unknown |
| V | Expressed as vanadium |
| Zn | Expressed as zinc |
| Zr | Expressed as zirconium |