Near-infrared absorption detection in picolitre liquid volumes using amplified fibre loop ring-down detection

Acetylene gas was detected through a ro-vibrational absorption line of the ν1-ν3 combination band at 1532 nm at a limit of detection of 50 ppm. Liquid 1-octyne and 1-dodecyne were detected in a 1 pL volume at detection limits of ∼20% dilution in dodecane through their C-H stretch vibrational overtone transition.