title: In-syringe extraction using dissolvable layered double hydroxide-polymer sponges templated from hierarchically porous coordination polymers.
abstract: Herein we report the use of cobalt porous coordination polymers (PCP) as intermediates to prepare advanced extraction media based on layered double hydroxides (LDH) supported on melamine polymer foam. The obtained dissolvable Ni-Co LDH composite sponges can be molded and used as sorbent for the in-syringe solid-phase extraction (SPE) of phenolic acids from fruit juices. The proposed sorbent is obtained due to the surfactant-assisted self-assembly of Co(II)/imidazolate PCPs on commercially available melamine foam, followed by the in situ conversion of the PCP into the final dissolvable LDH coating. Advantageous features for SPE are obtained by using PCPs with hierarchical porosity (HPCPs). The LDH-sponge prepared using intermediate HPCPs (HLDH-sponge) is placed in the headspace of a glass syringe, enabling flow-through extraction followed by analyte elution by the dissolution of the LDH coating in acidic conditions. Three phenolic acids (gallic acid, p-hydroxybenzoic acid and caffeic acid) were extracted and quantified using high performance liquid chromatography. Using a 5mL sample volume, the obtained detection limits were 0.15-0.35μgL(-1). The proposed method for the preparation of HLDH-sponges showed a good reproducibility as observed from the intra- and inter-day RSD's, which were <10% for all analytes. The batch-to-batch reproducibility for three different batches of HLDH-sponges was 10.6-11.2%. Enrichment factors of 15-21 were obtained. The HLDH-sponges were applied satisfactorily to the determination of phenolic acids in natural and commercial fruit juices, obtaining relative recoveries among 89.7-95.3%.
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra de Valldemossa km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
authors.forename: Milad
authors.initials: M
authors.lastname: Ghani
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra de Valldemossa km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain.
authors.forename: Rejane M
authors.initials: RM
authors.lastname: Frizzarin
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra de Valldemossa km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Maya
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra de Valldemossa km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain. Electronic address: victor.cerda@uib.es.
authors.forename: Víctor
authors.initials: V
authors.lastname: Cerdà
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D056831:Coordination Complexes / Q000737:chemistry*; D000067030:Fruit and Vegetable Juices / Q000032:analysis; D006878:Hydroxides / Q000737:chemistry; D062385:Hydroxybenzoates / Q000032:analysis / Q000302:isolation & purification*; D057230:Limit of Detection; D011108:Polymers / Q000737:chemistry; D016062:Porosity; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000295:instrumentation*; D013594:Syringes; D014227:Triazines / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D006878:Hydroxides; D062385:Hydroxybenzoates; D011108:Polymers; D014227:Triazines; C017616:phenolic acid; C011907:melamine
keywords: Hierarchically porous materials; In-syringe extraction; Layered double hydroxide; Phenolic acids; Porous coordination polymer