Determination of diquat herbicide by selective enrichment by column chromatography on imprinted polymer immobilised on silica gel

Abstract

A silica gel-bound, imprinted polymer for selective recognition of the diquat herbicide: 5,6-dihydropyrazino [1,2,3,4-1mnJ-l,lO-phenanthrohnium dichloride, is reported. It was used in the solid-phase extraction procedure, following liquid chromatography-differential pulse, adsorptive-stripping voltammetric (LC-DPAdSV) technique. The operational conditions for 100% retention of the diquat herbicide on a chromatographic column (13.0 x 1.4 cm, adsorbent bed 1.0 g) were realized at pH 6.9 and a flow rate of 5.0 mL min 1. The adsorbent used could be regenerated during elution with 5.0 mL M HCI within 20 min. The limit of detection was 0.65 nM (0.18 ppb) with an enrichment factor as high as 99-fold.

Polímeros biomiméticos em química analítica. Parte 1: preparo e aplicações de MIP ("Molecularly Imprinted Polymers") em técnicas de extração e separação

“…O oxigênio deve ser eliminado do meio reacional, pois retarda a reação de polimerização radicalar 30 . Por fim, o sólido polimérico resultante é moído, peneirado e submetido a uma lavagem com solvente para extração do analito, visando seu uso posterior 17,31 (Figura 2). O iniciador radicalar 2,2'-azo-bis-iso-butironitrila (AIBN) é o mais empregado na síntese dos MIP, mas outros também podem ser utilizados 30 (Figura 3).…”

Molecularly-imprinted polymers as synythetic mimics of bioreceptors. 2. Applications in modern biotechnology

“…That is associated with the possibility of synthesis of a stationary phase with the predicted selectivity either towards individual substance or a group of structurally-similar substances (depending on research or technological needs), provided by the technique of molecular imprinting. A number of publications were devoted to application of MIPs as a stationary phase in chromatographic identification of pharmaceuticals [2][3][4][5][6][7][8], drugs [9], amino acids [10][11][12][13], sugars [14][15][16], pesticides [17][18][19][20], antioxidants [21], peptides [22][23][24][25], phenols [26,27], etc.…”