Vista mpx icp oes

250 mg ± 10 mg of each < 10 µm separated sample was analysed for its acid-soluble metal content by dissolution in aqua regia (7.5 cm³ HCl, 2. cm³ HNO₃); three extractions were carried out per sample. This process was facilitated with a 1600 W CEM Mars 5 Microwave equipped with Teflon digestion tubes. Analysis was carried out using a Varian Vista MPX ICP-OES with SeaSpray nebuliser. Initial system stability checks were carried out with a 5 mg cm⁻³ solution of Mn during the torch alignment whereby the upper values must be in excess of 300,000 counts per second, and sample analysis exclusively used the axial position. A four-point linear calibration was achieved for each element; a calibration coefficient of > 0.99 for all elements was determined. Method verification was carried out using a certified reference material (CRM), river clay sediment LGC6139. 500 mg ± 10 mg of CRM was weighed out in triplicate, digested using aqua regia and analysed using ICP-OES. Determined concentrations of available metals were within 4% of the certified mean concentrations. Five replicates were carried out per sample.

Vaccinium myrtillus roots and above-ground portions of mycorrhizal and non-mycorrhizal plants were collected and oven dried at 70°C until reaching a constant weight. The material was totally digested by a treatment in nitric acid 6M at 90°C for 1 h. After filtration with GF/C filters (Whatman) and appropriate dilution in milliQ water, the metal content was finally determined using Induced Coupled Plasma-Optical Emission Spectrometry (ICP-OES Vista MPX, Varian, Department of Earth Sciences, University of Turin, Italy). Controls made up of ultrapure water and nitric acid were also analyzed. The results are the mean of four biological replicates, obtained by pooling the material from 8 V. myrtillus plants.

Chemical characterisation of the substrate was performed at the end of the experiment [65 ]. The following parameters were analysed in a substrate/water (1/5) extract: EC, pH, exchangeable cations (Ca²⁺, Mg²⁺, K⁺, Na⁺), P, B, micronutrients (Fe, Mn, Cu, Zn), and anions (Cl⁻, SO₄²⁻, NO₃⁻, H₂PO₄⁻).
At the end of the experiment, a sample of fully expanded mature leaves was freeze-dried and ground for analytical determinations. Dried-plant tissues were ground, and an aliquot (250 mg) was ashed at 550 °C. Ashes were dissolved in 0.7 N HNO₃, and phytotoxic elements (Na⁺ and B) were determined by coupled plasma optical emission spectrometry (Varian ICP-OES Vista MPX). Chloride was extracted from 50 mg of ground plant material with 2.5 mL of deionised water and measured by ion chromatography with a liquid chromatograph (Model ICS-3000, Thermo Fisher Scientific Inc., Logan, Utah, USA).

At the end of the experiment, the roots were carefully separated from the substrate and washed with distilled water. The shoots were separated into leaves and stems, which were also divided into lateral (growth after transplanting) and old stems. The leaf area of each plant was measured using a leaf area meter (model LI-3100, Li-Cor, Lincoln, NE, United States). Each plant material fraction was weighed fresh (FW) and after oven-drying for 48 h to determine the dry weight (DW). A sample of leaves was freeze-dried for metabolites determination.
The dried plant tissues were ground and an aliquot (250 mg) was ashed at 550°C. The ashes were dissolved in 0.7 N HNO₃, and macronutrients (P, K, Ca, and Mg), micronutrients (Fe, Cu, Mn, and Zn), and phytotoxic elements (Na and B) were determined by inductively coupled plasma optical emission spectrometry (Varian ICP-OES Vista MPX). Chloride and NO₃⁻ were extracted from 50 mg of ground plant material with 25 ml of deionized water and measured by ion chromatography with a liquid chromatograph (Model ICS-3000, Thermo Fisher Scientific Inc., United States). The nitrogen concentration was determined with a LECO FP-428 protein detector.

The NPs used for the ecotoxicity investigation were based on an inorganic matrix of orthovanadates doped with Eu³⁺ ions, GdVO₄: Eu³⁺, synthesized under hydrothermal conditions. Detailed description of the synthesis method and photophysical characterization of the NPs used are presented in a previous paper [42 (link)]. After the synthesis of NPs, the concentration of the stock solution was 3.54 mg/mL as determined by inductively coupled plasma-optical emission spectrometry (Varian ICP-OES VISTA-MPX). Before the assays, transmission electron microscopy (TEM) images were recorded using an HRTEM JEOL ARM 200F transmission electron microscope at the accelerating voltage of 200 kV. Dynamic light scattering (DLS) and zeta potential measurements were performed using a Malvern Zetasizer Nano ZS instrument. The concentration of the colloid sample was 1 mg/mL. Zeta potential was measured at physiological pH.
In order to evaluate the uptake of LDNCs by the plant organisms, elementary analysis was used. After 3 days of incubation, the seedlings were collected, weighed, rinsed, and mineralized in a pressure reactor with HNO₃. Next, the samples were analyzed using inductively coupled plasma optical emission spectroscopy (ICP OES).