Perchloroethylene A moderately volatile non-hydrocarbon solvent that that is being used as a replacement for Freon-113. Many grades are stabilized with hydrocarbons that make them unsuitable for TOG and TPH analysis. Hydrocarbon-free grades are available which make them usable for analysis by IR transmission methods. Since its heavier than water, the solvent after extraction will be on the bottom. Presently accepted as a Freon replacement in the UK. The perchloroethylene must be a spectroscopic grade that has not been stabilized with any hydrocarbon compound.

AK-225 A volatile HCFC solvent that nevertheless has low ozone depletion efficiency. It can be used as a replacement solvent for Freon-113. However, because of absorption in the C-H region, it has lower sensitivity than Freon-113 but is still usable for analysis by transmission methods. AK-225 is heavier than water and, therefore, the solvent after extraction will be on the bottom. At the lower concentration ranges, some method of moisture removal such as sodium sulfate may be required.

S-316 A proprietary, non-hydrocarbon solvent said by its manufacture to be environmentally safe. Since S-316 is heavier than water, the solvent after extraction will be on the bottom. Because of its transparency in the C-H region, it can be used with a 10mm cuvette. Approves S-316 as a replacement solvent for Freon. ASTM Standard Test Method D 7066-04.

Hexane A volatile hydrocarbon that is specified for EPA Method 1664. Because it is a hydrocarbon, it must be evaporated prior to making the infrared measurement to determine TOG or TPH levels in a sample, which takes approximately 3 - 5 minutes. Since hexane is lighter than water, the solvent, after extraction will rest on top, making it easy to deliver a measured amount of extract to the sample platform or plate with a 50 microliter auto pipette without losing any of the sample.

Pentane A volatile hydrocarbon preferred in Scandinavian countries over Hexane. Similar in performance and use to hexane although it has a lower boiling point and therefore will retain more of the low boiling point components. Pentane is lighter than water and like hexane will rest on top after the extraction.

Vertrel MCA A volatile HFC solvent that has been used primarily as a replacement solvent for Freon in cleaning operations. Because of its hydrocarbon absorption, like hexane, it must be evaporated prior to making the infrared measurement to determine TOG or TPH levels. Vertrel MCA is a suitable solvent to use instead of hexane. Vertrel MCA has no ozone depleting potential, is non-flammable and has low toxicity. As Vertrel MCA is heavier than water, the solvent after extraction will rest on the bottom. A microliter glass pipette can be used when preparing a sample; however, because of the weight of Vertrel, the extract should be delivered to the sample platform or plate with a 50 microliter syringe, rather than a pipette for analysis.