Ethanol Concentration

Methods for determining ethanol concentration in water.

NIR gas analysis
Paper on measuring ethanol from head gas, link. Uses a Binos 100 gas analyzer, see the manual, principal of operation on p59-60. Uses two interference filters, one for ethanol absorbance region (4300nm), other for reference (4000nm) where no absorbance is expected.

FTIR liquid analysis
Using ATR with a zinc selenide crystal. ZnSe crystals are farily expensive and hard to source.

This usually is a infrared spectroscopy technique, so a diffraction grating is necessary and moving parts to scan over the frequency range. This reduces source light intensity and increases complexity. The solution is more general.

College lab in FTIR

IR LED system patent using a tunable IR dichromic / interference filter: link. This filter is expensive and hard to source.

Use one or more IR diodes to measure IR adsorption by ethanol
IR LED, 4200nm, 0.010 mW Quasi-CW, 0.2 mW Pulsed, $70
LED43 10 μW (200 μW Pulsed), TO18, $37.5. Broad spectrum 3000-5000nm.

Mid IR filters, 500 nm range $315; narrow bandpass, $265

Enzymatic / fluorescent
College chem lab

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>