Table 2.
Illustrative examples of flow-based procedures exploiting unstable derivatives.
| Analyte | Unstable Derivative | Application | Ref. |
|---|---|---|---|
| Acetylcysteine | Bromine | Pharmaceuticals | [30] |
| Bromate, bromide | Intermediate of the 5-Br-PADAP and SCN-reaction | Tap and mineral waters | [100] |
| Chloride | Chorine produced by photochemical oxidation | Urine and waters | [102] |
| Cr(VI) | Intermediate of reaction with H2O2 | Fresh and wastewaters | [103] |
| Cyanide | Intermediate of the pyridine-barbituric acid reaction | Natural and wastewaters | [104] |
| Ethanol | Ce(IV) ethanolic complex | Alcoholic beverages | [105] |
| Formaldehyde | Intermediate of reaction with phloroglucinol | Foodstuffs | [106] |
| Manganese | Intermediate of oxidation of 4,4′-bis(dimethylamino)-diphenylmethane by periodate | Fresh and estuarine waters | [107] |
| Manganese | Mn(III)/EDTA complex | Freshwaters | [108] |
| Metoclopramide, tetracaine | Intermediate of pharmaceuticals oxidation by dichromate, in the presence of oxalate under acidic conditions | Pharmaceutical samples | [109] |
| Total polyphenols | Enol derivative formed by reaction with hypochlorite | Wines, tea | [101] |
5-Br-PADAP: 2-(5-dibromo-2-pyridylazo)-5-(diethylamino)phenol; EDTA: Ethylenediaminetetraacetic acid.