Polydimethylsiloxane/covalent triazine frameworks coated stir bar sorptive extraction coupled with high performance liquid chromatography-ultraviolet detection for the determination of phenols in environmental water samples

Multi-template imprinted polymers for simultaneous selective solid-phase extraction of six phenolic compounds in water samples followed by determination using capillary electrophoresis

“…Phenolic compounds especially chlorinated ones are toxic and persistent in environment with low concentration, which have been included in the list of priority pollutants devised by European Union and United State Environmental Protection Agent [1]. For the enrichment of trace/ultra-trace level phenolic compounds, many kinds of traditional and novel pretreatment techniques have been proposed, such as, cloud point extraction [2], liquid phase microextraction [3], dispersive liquid-liquid microextraction [4], solid-phase extraction (SPE) [5], magnetic extraction [6], solidphase microextraction [7] and stir-bar sorptive extraction [8]. Among them, SPE as a convenient and easy to automate technique has been widely used in environment, food and biological fields [9].…”

Covalent Organic Frameworks in Sample Preparation

“…As can be seen in the table, COFs have been applied in SPME for the extraction and preconcentration of numerous analytes, such as PAEs [ 96 , 97 ], phenols [ 98 ], pesticides [ 99 ], PCBs [ 100 ], pyrethroids [ 101 ], chlorophenols (CPs) [ 98 , 102 ], benzene homologues [ 103 ], PAHs [ 104 ] and polybrominated diphenyl ethers (PBDEs) [ 105 ] from a wide variety of samples, including indoor air [ 103 ], environmental [ 105 ] and bottled water [ 96 ] samples, grilled meat [ 104 ], honey [ 98 , 102 ], canned peaches [ 102 ], fruits and vegetables [ 99 , 101 ], juices [ 97 ] and different aquatic organisms (snakeheads, catfish, bream, crucian, white shrimp and base shrimp) [ 100 ]. Concerning SBSE, the application of COFs as coatings has only been developed up to now for the extraction of PCBs from soils [ 106 ] and phenols from environmental water [ 107 ].…”

“…The main modality of SPME in which COFs have been employed has been head-space SPME (HS-SPME) [ 96 , 97 , 99 , 100 , 101 , 102 , 103 ], though there are also some direct immersion SPME (DI-SPME) applications [ 98 , 104 , 105 ]. Most COFs used under these modalities of SPME were prepared following a solvothermal synthesis approach [ 96 , 97 , 98 , 104 , 105 ], although other synthetic strategies have been successfully developed (also for SBSE coatings), involving ionothermal cyclotrimerization [ 107 ], solvent-free mechanochemical grinding [ 102 ], room temperature condensation [ 100 ] or the photo-induced thiol-ene click chemistry synthesis method [ 99 ], among others. Concerning fibers’ preparation, the most common approach has been the use of corroding agents to create an adequate rough surface on a stainless-steel wire prior to the incorporation of the coating.…”

“…Concerning coated stir-bars, one of the proposed procedures involved the use of a capillary glass with an iron wire within as the support structure for the polydimethylsiloxane (PDMS)/covalent triazine framework (CTF) coating, which was obtained using a sol-gel technique [ 107 ]. Another example used Fe 3 O 4 @mTiO 2 -COF as the coating and prepared the COFs via a condensation reaction with TAPB and TA and the m-NPs through a solvothermal approach.…”

“…The physical and chemical properties that determine the enrichment factors (EFs) of both techniques vary between the different COFs, there being tangible differences between compounds regarding the main effect driving the extraction. Nevertheless, it can be stated that all the selected COFs share common interactions with the target analytes, such as hydrophobic [ 97 , 98 , 99 , 100 , 101 , 102 , 103 , 105 ] or hydrophilic interactions [ 96 ], hydrogen bonding [ 96 , 101 , 107 ] and/or π–π stacking [ 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 107 ]. Other key properties to ensure a quantitative extraction were pore size [ 97 , 100 , 104 , 105 ], porosity [ 99 , 105 ] and surface areas [ 99 , 101 , 104 ].…”