Determination of low solvent concentration by nano-porous silicon photonic sensors using volatile organic compound method.
Environ Technol
; 40(26): 3403-3411, 2019 Nov.
Article
in En
| MEDLINE
| ID: mdl-29733761
ABSTRACT
A vast majority of the organic solvents used in industry and laboratories are volatile, hazardous and toxic organic compounds, they are considered as a potent problem for human health and a cause of environmental pollution. Although analytical laboratory methods can determine extremely low solvent concentration, the sensing method with low cost and high sensitivity remains a conundrum. This paper presents and compares three methods (volatile organic compound (VOC), liquid drop and saturated vapour pressure) for determination of organic solvents in a liquid environment by using photonic sensor based on nano-porous silicon (pSi) microcavity structures. Among those, the VOC method provides the highest sensitivity at low solvent volume concentrations because it can create a high vapour pressure of the analyte on the sensor surface owing to the capillary deposition of the organic solvent into the silicon pores. This VOC method consists of three steps:
heating the solution with its particular boiling temperature, controlling the flowing gas through liquid and cooling sensor. It delivers the highest sensitivity of 6.9â nm/% at a concentration of 5% and the limit of detection (LOD) of pSi-sensor is 0.014% in case of ethanol in water when using an optical system with a resolution of 0.1â nm. Especially, the VOC method is capable of detecting low volume concentration of methanol in two tested ethanol solutions of 30% (v/v) and 45% (v/v) with the LOD of pSi-sensor up to 0.01% and 0.04%, respectively. This result will help pave a way to control the quality of contaminated liquor beverages.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Volatile Organic Compounds
Limits:
Humans
Language:
En
Journal:
Environ Technol
Journal subject:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Year:
2019
Document type:
Article
Affiliation country:
Vietnam