TiO2 nanoparticle–Coated 3D-Printed porous monoliths enabling highly sensitive speciation of inorganic Cr, As, and Se

4D-Printed Elution-Peak-Guided Dual-Responsive Monolithic Packing for the Solid-Phase Extraction of Metal Ions

“…Under the optimized operating conditions [P (NIPAM) mode] for the SPE column with the 4D-printed dual-responsive monolithic packing (Table S2; sample volume: 0.5 mL; sample throughput: 17.1 h –1 ), the absolute extraction efficiencies of the metal ions ranged from 91.9 to 95.1% [ratios of the elution peak areas (10 μg L –1 ) with and without extraction; Table ], their correlation coefficients ( R ) in the working range were all greater than 0.9997 (Figure S9A,B), and the enhancement factors (EFs) ranged from 13.0 to 19.3 [ratios of H max (10 μg L –1 ) after and before extraction , ]. Compared with previously reported 3D-printed SPE devices − and commercial SPE devices − for sample pretreatment and trace-element determination (Table S3), the SPE column with the 4D-printed dual-responsive monolithic packing developed in this study provided superior analytical characteristics, including much lower MDLs (under the minimum sample volume), higher throughput, and greater extraction capacities. To validate the applicability of our analytical method for the reliable determination of metal ions in natural water and urine samples, the concentrations of the investigated metal ions in an SRM and CRMs were measured.…”

“…Three-dimensional printing (3DP) technologies are highly applicable to the customization of diverse analytical devices featuring special geometric characteristics or functionality. − The coupling of 3D-printed SPE devices with atomic spectrometric techniques has been demonstrated to allow improvements in adaptability, diversity, and analytical performance for trace-metal analysis. − Moreover, emerging four-dimensional printing (4DP) technologies based on the 3DP of stimuli-responsive materials are capable of effectively fabricating stimuli-responsive analytical devices possessing time-dependent shape programming and/or shape-memory properties. − At present, studies utilizing stimuli-responsive materials to improve the analytical performance of conventional SPE schemes are limited. It is necessary to explore the capability of 4DP technologies for advancing SPE-based analytical schemes to develop future sample-preparation techniques.…”

“… 32 − 37 The coupling of 3D-printed SPE devices with atomic spectrometric techniques has been demonstrated to allow improvements in adaptability, diversity, and analytical performance for trace-metal analysis. 38 − 48 Moreover, emerging four-dimensional printing (4DP) technologies based on the 3DP of stimuli-responsive materials are capable of effectively fabricating stimuli-responsive analytical devices possessing time-dependent shape programming and/or shape-memory properties. 49 − 53 At present, studies utilizing stimuli-responsive materials to improve the analytical performance of conventional SPE schemes are limited.…”

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…For the determination of inorganic species of As, Cr and Se in high-salt matrices by ICP-MS, Chen et al developed a SPE procedure in which selectivity was obtained by pH control. 76 A 3-D printed monolithic column of polyamide was modified with TiO 2 NPs, and samples were loaded at pH 2 (to selectively retain As V and Cr VI , but both Se IV and Se VI ), pH 6 (to selectively retain Se IV ) or pH 12 (to selectively retain As III and Cr III ). The loading, rinsing, elution and washing steps were automated in a two-column system with appropriate switching valves.…”

Atomic spectrometry update: review of advances in elemental speciation

“…Post-printing functionalisation can enhance the functionality and applicability of analytical devices manufactured using three-dimensional printing. In a study by Chen et al 44 3D-printed SPE columns incorporating TiO 2 NP coated porous polyamide monoliths were used to develop a highly sensitive SPE-based method for the speciation of iAs (and Cr and Se) in high salt content samples such as natural water and human urine samples. Treatments with a formic acid (30%, v/v) solution and a NaHCO 3 (0.5%, w/v) solution TiO 2 NPs (1.0%, w/v) were used for in situ fabrication of the SPE columns.…”