. 2022 Feb 26;27(5):1563. doi: 10.3390/molecules27051563

Table 3.

Selected applications of flow-based optosensing involving chemical derivatization.

Analyte	Sample	Derivative	Sorbent	LOD (µg L⁻¹)	CV (%)	Remarks	Ref.
Bromate ^a	Drinking water	Radical formed from oxidation of chlorpromazine	Discovery DSC-MCAX	0.9	<3.6	In-line oxidation of chlor-promazine by the analyte and sorption of the product	[117]
Formaldehyde ^a	Ethanol fuel	3,5-diacetyl-1,4-dihydrolutidine	C18-bonded silica	30	2.2	In-line derivative formation	[118]
Glucose ^a	Pharmaceuticals	Thionine	Actigel ALD beads	3 × 10⁴	<5.0	Thionine reduction by NADH yielded in the enzimatic glucose oxidation	[119]
Iron ^a	Natural waters	Fe(II)/TAN complex	C18-bonded silica	15	4.0	10-fold higher sensitivity in relation to measurements in solution	[116]
Nickel/Zinc ^a	Copper-alloys	Metal-TAN complexes	C18-bonded silica	―	1.1–2.1	Simultaneous determination by different sorption rates	[115]
Nitenpyram ^b	Vegetables	Product of analyte photodegradation	Sephadex QAE-A25	0.5	2.6–3.1	On-line analyte photodegradation and transient retention of the derivative at the solid support	[120]
Oxalate ^a	Vegetables/spicies	Ti(IV)-ECR complex	Silica-titania xerogel	1 × 10⁴	―	Discoloration of the dye adsorbed on the solid support	[121]
Resveratrol ^b	Beers	2,4,6-trihydroxy-phenanthren	Sephadex QAE-A25	1.0	1.8	On-line analyte photodegradation and transient retention of the derivative at the solid support	[122]
Tin ^a	Fruit juices	Sn(IV)-Pyrocatechol violet complex	Sephadex QAE-A25	0.3	2.5	In-line derivative formation	[123]
B12 Vitamin ^c	Pharmaceuticals	4-Aminophthalate	Dowex 1-X8	0.5	5.3	Bead injection of luminol immobilized on the solid support	[124]

^a: Spectrophotometric, ^b: fluorimetric, ^c: chemiluminescence detection. ECR: Eriochrome cyanine R; TAN: 1-(2-thiazolylazo)-2-naphthol.