Automated thin-film microextraction coupled to a flow-through cell: somewhere in between passive and active sampling

Abstract

A prototype for the automated thin-film microextraction of pharmaceuticals from aqueous solutions has been developed and is presented here for the first time. With a software-controlled setup, extraction methods for ivermectin and iohexol have been developed. The widely used antiparasitic agent ivermectin is non-polar and has a high tendency to sorb to surfaces. In contrast to this, the nonionic but polar iodinated X-ray contrast agent iohexol is freely water soluble. With these two substances, a wide range of polarity is covered. Sorption kinetics and thermodynamics of ivermectin and iohexol were studied. With the presented passive sampling approach, it was possible to extract up to 96.2% ivermectin with a C-phase within 1 h and up to 74.6% of iohexol with a PS-DVB phase within 36 h out of water. Using abamectin as internal standard, it was possible to quantitatively follow dissipation of ivermectin in a simulated surface water experiment. Predominantly, the newly developed prototype can be used for automated and time-resolved extraction of xenobiotics from waterbodies under field conditions, for the extraction of substances under laboratory conditions as an alternative to the elaborate solid-phase extraction, and for the automated control of chemical reaction kinetics.

Thin film microextraction: Towards faster and more sensitive microextraction

“…It was also validated for relatively smaller volumes (i.e. 10-20 µL) by spotting the biofluid onto the surface of the blade[16,17]. The results satisfied the stringent WADA requirements in terms of both precision and accuracy.…”

“…production of biocompatible TFME devices where extractive particles are immobilized in polyacrylonitrile (PAN). Recently, ultra-thin extractive phases have become increasingly prevalent and in-demand for the most sensitive applications, such as direct coupling to mass spectrometry where fast desorption kinetics are absolutely critical [16][17][18]. In these types of applications, dip coating is one of the most advantageous coating approaches for the preparation of smooth-surface coatings with coating thicknesses as thin as several micrometers.…”

“…Besides this commercially available instrument, several works have demonstrated the feasibility of high-throughput TFME using semi-automatic in-house setups that can be used not only for routine analytical applications, but also for practical and rapid screening and evaluation of new coatings [7,38]. Another high throughput sampling approach was proposed by Wohde et al [17], using a flow-through cell model that allows Direct coupling of TFME devices to various detection systems relies on preforming the sample preparation step, followed by introduction of the extracted analytes into the instrument. This approach omits the time consuming chromatographic or capillary electrophoretic separation step, guaranteeing rapid, yet accurate analyses.…”

In‐situ formation of Zn–Al layered double oxides on electrochemically anodized nanoporous aluminum film as sorbent for chlorophenols extraction from water and wastewater followed by determination using HPLC

“…The other attempts focused on the use of polydimethylsiloxane/divinylbenzene (PDMS/DVB) and PDMS/DVB‐carbon mesh supported membranes for TFME of pesticides from aqueous samples [7]. The other extracting phase, including MOF‐199 in polystyrene [8], 1‐dodecylimidazolium [9], ZnO nanorods modified with phenyl carbamate [10], polystyrene [11], diatomaceous earth [12], aptamer coated paper [13], magnetic polybutylene terephthalate [14], silica gel thin film [15], ZnO nanoparticles (NPs) doped polyamide [16], single‐wall carbon nanohorn suprastructures [17], cork [18], hierarchical zeolitic imidazolate framework‐67 [19], Co 3 O 4 nanorod arrays [20], and porous titania [21], were also synthesized and utilized as sorbent in TFME. Current research of TFME is focused on the investigation of new coatings.…”

Sorption of selected antiparasitics in soils and sediments

“…When used to control sea lice infestations, IVM can be quantified in low concentrations in marine sediments around fish farms [ 54 ]. In water, DT 50 -values of < 6 [ 55 ] and 15.9 h [ 56 ] have been reported for IVM in simulated sediment/water systems. This indicates rapid dissipation from aqueous media; presumably binding onto suspended particles and sediment.…”