A new formaldehyde optical sensor: Detecting milk adulteration

authors	Verissimo, MIS; Gamelas, JAF; Fernandes, AJS; Evtuguin, DV; Gomes, MTSR
nationality	International
journal	FOOD CHEMISTRY
author keywords	Formaldehyde; Milk; Food adulteration; Optical fibre sensor; Polyoxometalate; Acetylacetone method
keywords	POLYOXOMETALATE; FOOD; FRAUD; FILM
abstract	A sensor consisting of an optical fibre with the exposed tip coated with the polyoxometalate salt [(C4H9)(4)N](4)H [PMo10V2O40], specially designed to be insoluble in water, which UV-Vis spectrum changed in contact with formaldehyde, is presented. The sensor limit of detection for formaldehyde was 0.2 mg L-1, and the limit of quantification was 0.6 mg L-1, which were close to the conventional spectrophotometric method values of 0.2 mg L-1 and 0.5 mg L-1, respectively, and lower than the tolerable limit for ingested food. The sensor was tested for formaldehyde quantification in milk, as its deliberate addition is a matter of concern. The results obtained analysing formaldehyde in milk samples by the optical sensor and by the conventional method were not statistically different (alpha = 0.05).
publisher	ELSEVIER SCI LTD
issn	0308-8146
isbn	1873-7072
year published	2020
volume	318
digital object identifier (doi)	10.1016/j.foodchem.2020.126461
web of science category	Chemistry, Applied; Food Science & Technology; Nutrition & Dietetics
subject category	Chemistry; Food Science & Technology; Nutrition & Dietetics
unique article identifier	WOS:000520858000004