Table 1.

Analytical properties of a variety of infrared spectroscopic sensors for toluene in water.

Method	IR Region	Detection Limit	Reference
ATR	Middle	80 ppb	[20]
Fiber optic	Middle	1.3 ppm	[21]
Transmittance	Middle	6.9 ppm	[22]
Transmittance	Near	1.8 ppm	[23]