Exploiting dynamic reaction cell technology for removal of spectral interferences in the assessment of Ag, Cu, Ti, and Zn by inductively coupled plasma mass spectrometry

Analytical methods based on dynamic-reaction cell (DRC) technology using ammonia as a reaction gas have been developed for the determination of ultra-trace Ti, Zn, Cu and Ag by inductively coupled plasma mass spectrometry (ICP-MS). Challenging spectral interferences from complex matrices were demonstrated to be overcome by DRC, and several DRC approaches (on-mass and mass-shift) using ammonium (NH3) as a reaction gas were assessed and compared to the standard or “vented” mode analysis. Ammonium cluster ions were generated for Ti, Cu, Zn, and Ag (mass shift approach). The on-mass approach was also explored to take advantage of collisional focusing phenomena. In addition, DRC operating conditions were optimised by modifying NH3 gas flow rate and rejection parameter q (RPq). The optimised conditions were applied to show the usefulness of either on-mass or mass-shift approaches when removing Ca and P interferences. Finally, the sensitivity of all measurement modes was studied and excellent limits of detection (at few ng L−1 levels) were assessedThe authors wish to acknowledge the financial support of the Ministerio de Economía y Competitividad, Gobierno de España (project INNOVANANO, reference RT2018-099222-B-100), and the Xunta de Galicia (Grupo de Referencia Competitiva, grant number ED431C2018/19)S

Single-particle inductively coupled plasma mass spectrometry using ammonia reaction gas as a reliable and free-interference determination of metallic nanoparticles

Intensive production of nanomaterials, especially metallic nanoparticles (MNPs), and their release into the environment pose several risks for humans and ecosystem health. Consequently, high-efficiency analytical methodologies are required for control and characterization of these emerging pollutants. Single-particle inductively coupled plasma – mass spectrometry (SP-ICP-MS) is a promising technique which allows the determination and characterization of MNPs. However, several elements or isotopes are hampered by spectral interferences, and dynamic-reaction cell (DRC) technology is becoming a useful tool for free interference determination by ICP-MS. DRC-based SP-ICP-MS methods using ammonia as a reaction gas (either on-mass approach or mass-shift approaches) have been developed for determining titanium dioxide nanoparticles (TiO2 NPs), copper oxide nanoparticles (CuO NPs), copper nanoparticles (Cu NPs), and zinc oxide nanoparticles (ZnO NPs). The effects of parameters such as ammonia flow rate and dwell time on the peak width (NP transient signal in SP-ICP-MS) were comprehensively studied. Influence of NP size and nature were also investigateThe authors wish to acknowledge the financial support of the Ministerio de Economía y Competitividad (INNOVANANO projects, reference RT2018-099222-B-100), and the Xunta de Galicia (Grupo de Referencia Competitiva, grant number ED431C2018/19)S

Development of a micro-solid-phase extraction molecularly imprinted polymer technique for synthetic cannabinoids assessment in urine followed by liquid chromatography–tandem mass spectrometry

Several molecularly imprinted polymers (MIPs) have been synthesized for the first time using various synthetic cannabinoids (JWH007, JWH015 and JWH098) as template molecules. Ethylene dimethacrylate (EDMA) was used as a functional monomer for all cases. Similarly, divinylbenzene (DVB) and 2,2′-azobisisobutyronitrile (AIBN) were used as cross-linker and initiator, respectively. The prepared MIPs have been fully characterized and evaluated as new selective adsorbents for micro-solid phase extraction (μ-SPE) of synthetic cannabinoids in urine. The developed MIP-μ-SPE devices consisted of a polypropylene (PP) porous membrane containing the adsorbent (novel porous membrane protected micro-solid phase extraction based on a cone-shaped device) for operating in batch mode, which allowed a fast and integrated extraction-cleanup procedure. High performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) was used for quantifying the analytes after MIP-μ-SPE. The best performances were obtained for MIPs prepared from JWH015 as a template. Optimum loading conditions were found to be urine pH of 5.0 and adsorption time of 8.0 min under mechanical (orbital-horizontal) stirring at 100 rpm. The composition of the eluting solution consisted of 75:20:5 heptane/2-propanol/ammonium hydroxide. The elution was assisted by ultrasounds (37 kHz, 325 W) for 8.0 min. In addition, studies regarding selectivity have also been addressed for several drugs of abuse under optimized loading/adsorption conditions. Validation of the method showed good precision and analytical recovery by intra-day and inter-day assays (RSD values lower than 7 and 10% for intra-day and inter-day precision, and within the 83–100% range for intra-day and inter-day analytical recovery)

Quantitative titanium imaging in fish tissues exposed to titanium dioxide nanoparticles by laser ablation-inductively coupled plasma-mass spectrometry

Imaging studies by laser ablation–inductively coupled plasma mass spectrometry have been successfully developed to obtain qualitative and quantitative information on the presence/distribution of titanium (ionic titanium and/or titanium dioxide nanoparticles) in sea bream tissues (kidney, liver, and muscle) after exposure assays with 45-nm citrate-coated titanium dioxide nanoparticles. Laboratory-produced gelatine standards containing ionic titanium were used as a calibration strategy for obtaining laser ablation–based images using quantitative (titanium concentrations) data. The best calibration strategy consisted of using gelatine-based titanium standards (from 0.1 to 2.0 μg g−1) by placing 5.0-μL drops of the liquid gelatine standards onto microscope glass sample holders. After air drying at room temperature good homogeneity of the placed drops was obtained, which led to good repeatability of measurements (calibration slope of 4.21 × 104 ± 0.39 × 104, n = 3) and good linearity (coefficient of determination higher than 0.990). Under the optimised conditions, a limit of detection of 0.087 μg g−1 titanium was assessed. This strategy allowed to locate prominent areas of titanium in the tissues as well as to quantify the bioaccumulated titanium and a better understanding of titanium dioxide nanoparticle spatial distribution in sea bream tissuesOpen Access funding provided thanks to the CRUE CSIC agreement with Springer Nature. Authors thank funding from European Union—Interreg POCTEP (ACUINANO, reference 07-12-ACUINANO_1_E); Ministerio de Economía y Competitividad (FOODNANORISK, reference PID2021-125276NB-I00); and Xunta de Galicia (Grupo de Referencia Competitiva, reference ED431C 2022/029)S

Bioaccumulation of titanium dioxide nanoparticles in green (Ulva sp.) and red (Palmaria palmata) seaweed

A bioaccumulation study in red (Palmaria palmata) and green (Ulva sp.) seaweed has been carried out after exposure to different concentrations of citrate-coated titanium dioxide nanoparticles (5 and 25 nm) for 28 days. The concentration of total titanium and the number and size of accumulated nanoparticles in the seaweeds has been determined throughout the study by inductively coupled plasma mass spectrometry (ICP-MS) and single particle-ICP-MS (SP-ICP-MS), respectively. Ammonia was used as a reaction gas to minimize the effect of the interferences in the 48Ti determination by ICP-MS. Titanium concentrations measured in Ulva sp. were higher than those found in Palmaria palmata for the same exposure conditions. The maximum concentration of titanium (61.96 ± 15.49 μg g−1) was found in Ulva sp. after 28 days of exposure to 1.0 mg L−1 of 5 nm TiO2NPs. The concentration and sizes of TiO2NPs determined by SP-ICP-MS in alkaline seaweed extracts were similar for both seaweeds exposed to 5 and 25 nm TiO2NPs, which indicates that probably the element is accumulated in Ulva sp. mainly as ionic titanium or nanoparticles smaller than the limit of detection in size (27 nm). The implementation of TiO2NPs in Ulva sp. was confirmed by electron microscopy (TEM/STEM) in combination with energy dispersive X-Ray analysis (EDX)The authors wish to thank the fnancial support of Ministerio de Economía y Competitividad (project INNOVANANO, reference RT2018-099222-B-100), European Union (INTERREG Atlantic Area, project NANOCULTURE, reference EAPA590/2018), and Xunta de Galicia (Grupo de Referencia Competitiva, grant number ED431C 2022/29)S

Acute aquatic toxicity to zebrafish and bioaccumulation in marine mussels of antimony tin oxide nanoparticles

Antimony tin oxide (Sb2O5/SnO2) is effective in the absorption of infrared radiation for applications, such as skylights. As a nanoparticle (NP), it can be incorporated into films or sheets providing infrared radiation attenuation while allowing for a transparent final product. The acute toxicity exerted by commercial Sb2O5/SnO2 (ATO) NPs was studied in adults and embryos of zebrafish (Danio rerio). Our results suggest that these NPs do not induce an acute toxicity in zebrafish, either adults or embryos. However, some sub-lethal parameters were altered: heart rate and spontaneous movements. Finally, the possible bioaccumulation of these NPs in the aquacultured marine mussel Mytilus sp. was studied. A quantitative analysis was performed using single particle inductively coupled plasma mass spectrometry (sp-ICP-MS). The results indicated that, despite being scarce (2.31 × 106 ± 9.05 × 105 NPs/g), there is some accumulation of the ATO NPs in the mussel. In conclusion, commercial ATO NPs seem to be quite innocuous to aquatic organisms; however, the fact that some of the developmental parameters in zebrafish embryos are altered should be considered for further investigation. More in-depth analysis of these NPs transformations in the digestive tract of humans is needed to assess whether their accumulation in mussels presents an actual risk to humans.Fundação para a Ciência e Tecnologia | Ref. 2020.04021.CEECIN

Synthetic cathinones determination by liquid chromatography-mass spectrometry after ultrasound membrane assisted extraction

The extraction time for membrane-assisted solvent extraction (MASE) when isolating synthetic cathinones from urine has been speeded up to 30 min by using ultrasounds. Separation and determination of eleven synthetic cathinones was further performed liquid chromatography-tandem mass spectrometry (LC-MS/MS). The ultrasound assisted MASE consisted of adjusting 5.0 mL of urine at pH 11.8 and performing the extractive process with 400 μL of n-hexane as an acceptor phase inside the polypropylene membrane under ultrasonication at room temperature. Synthetic cathinones exhibiting LogP values higher than 2.0, such as 3,4-dimethyl methcathinone, methylendioxypyrovalerone, and naphyrone), were efficiently extracted and pre-concentrated. Other synthetic cathinones (LogP between 2.0 and 0.7) were found to exhibit a lower mass transfer. The method was found to be matrix dependent, and a matrix-matched calibration was required for measurements. The achieved limits of detection (LOD) were between 0.03 (flephedrone) to 0.29 (ethylone) µg L-1, with relative standard deviations (RSDs) within the 6–14% and 7–19% ranges for intraday and inter-day assays, and intraday and inter-day analytical recoveries from 84 to 115% and 85 to 118%, respectively. The developed method was finally applied to urine samples from volunteers attending a music festivalThis work was supported by the Dirección Xeral de I + D – Xunta de Galicia Grupos de Referencia Competitiva (project number ED431C 2022/029)S

Rapid and selective determination of osmium(IV) by UV-visible spectrophotometry using <i>o</i>-methylphenyl thiourea as a chromogenic chelating ligand: sequential separation of osmium(IV), rhodium(III) and platinum(IV)

<div><p>The objective of this research work was to develop a simple, highly sensitive and precise method for spectrophotometric determination of osmium(IV). <i>O</i>-Methylphenyl thiourea (OMPT) coordinates with osmium(IV) as a 1:1 (osmium(IV)–OMPT) complex in hydrochloric acid media (0.8 mol l⁻¹). The novelty of the investigated method is instant complex formation at room temperature with no need of heating or standing. The complex is stable for more than 8 days. The method is applicable over a wide linearity range (up to 110 µg ml⁻¹). A low reagent concentration is required (2 ml, 0.009 mol l⁻¹ in ethanol). The complex exhibits maximum absorption in the range of wavelength 510–522 nm and 514 nm was selected for further study. The molar absorptivity was 1.864 × 10³ l mol⁻¹ cm⁻¹, Sandell’s sensitivity was 0.102 µg of osmium(IV) cm⁻². Proposed method was successfully applied for separation and determination of osmium(IV) from binary and ternary synthetic mixtures containing associated metal ions. A scheme for mutual separation of osmium(IV), rhodium(III) and platinum(IV) is developed.</p></div