Tetrahydrofuran

Tetramethylene oxide; C₄H₈O = 72.11 (109-99-9)

Clear, colourless, flammable liquid, miscible with water, with ethanol (96%).

, about 0.89.

Do not distil if the tetrahydrofuran does not comply with the test for peroxides.

Peroxides Place 8 mL of potassium iodide and starch solution in a 12 mL ground-glass-stoppered cylinder about 1.5 cm in diameter. Fill completely with the substance to be examined, shake vigorously and allow to stand protected from light for 30 min. No colour is produced.

Tetrahydrofuran used in spectrophotometry complies with the following additional test.

Absorbance (2.2.25) Maximum 0.70 at 255 nm, 0.10 at 270 nm, 0.01 at 310 nm, determined using water as compensation liquid.