Icap tq icp ms

The procedure for determining the elements is described by Pasławski and Migaszewski [51 ] and Kalisz et al. [52 (link)]. Briefly, randomly-selected lettuce leaves were shredded and dried at 70 °C in a dryer. The dried samples were ground using a Pulverisette 14 ball mill (Fritsch GmbH, Idar-Oberstein, Germany; 0.5-mm sieve). After that, 3 g samples were placed in TFM vessels with a volume of 100 cm³ and mineralized in 10 cm³ 65% super pure HNO₃ (Merck no. 100443.2500) in a Mars 5 Xpress (CEM Corporation, Matthews, NC, USA) microwave digestion system. After cooling, the samples were transferred to 25 cm³ flasks with redistilled water. The total contents of the elements Ag, Au, and Pt were analysed by ICP-MS/MS triple quadruple spectrometer iCAP TQ ICP-MS (Thermo Fisher Scientific Inc., Bremen, Germany). Their determination was conducted using the following measurement mode for individual isotopes of elements: S-SQ-KED for ¹⁹⁷Au, ¹⁰⁹Ag, and ¹⁹⁵Pt.

The dry matter (DM) content of the feed was determined by drying the samples at 103 °C to constant weight, and faeces were freeze-dried. The samples of the diets and faeces were milled at 1 mm before mineral and chemical analyses. The analyses of Zn and TiO₂ in the diets were performed in quadruple and duplicate analyses, respectively, whereas the analyses of Zn and TiO₂ in the faeces were performed in duplicate and single analyses, respectively. Prior to Zn analysis, feed, faeces and serum samples were digested with concentrated HNO₃ (67–69%), followed by destruction using a microwave system (Ultra wave, single reaction chamber, Milestone Inc, Shelton, CT, USA). The Zn content was measured on an iCAP TQ ICP-MS (Inductively Coupled Plasma-Mass Spectrometer; Thermo Scientific, Bremen, Germany) as described in detail by Hansen et al. [25 (link)]. Titanium oxide was analysed by the digestion of samples with sulphuric acid and by measuring the absorbance after the addition of hydrogen peroxide [26 (link)] with the modification that 15 mL of 30% hydrogen peroxide was added instead of 10 mL, and before measuring the absorbance, five additional drops of hydrogen peroxide were added.

Nitric acid 65% (Merck, Darmstadt, Germany), hydrogen peroxide 30% (Merck, Darmstadt, Germany) solutions, and ultrapure deionized water with a resistivity of 18.2 MΩ cm were obtained from a Milli-Q Plus water purification system (Millipore, Bedford, MA, USA). The multielement standard solution consists of B, Na, Mg, Al, Si, K, Ca, V, Cr, Mn, Cu, Zn, Ga, As, Rb, Sr, Ag, Cd, Sb, Cs, Ba, Hg, and Pb (TraceCERT, Merck, Darmstadt, Germany), and nine rare earth elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, and Gd) 10 mg/L each element were provided by Sigma-Aldrich (Missouri, USA).
The main instruments used include the ATR-FTIR spectrometer (Nicolet™ iS50, Thermo Fisher Scientific, USA), MARS6 microwave oven (CEM Corporation, Matthews, NC, USA), and iCap TQ ICP/MS (Thermo Fisher Scientific, Bremen, Germany).

The carbonaceous species, water-soluble ions, and metals in the PM_2.5 samples were analyzed. Carbonaceous species that were measured included organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC). The detailed measurements of OC, EC, WSOC, and ions are reported in our previous study [33 (link)]. A Desert Research Institute (DRI) thermal/optical carbon analyzer was used to evaluate OC and EC, following the thermal/optical transmittance (TOT) protocol. The WSOC concentration was assessed using a TOC analyzer (TOC-L Shimadzu).
Li, Al, V, Cr, Mn, Mg, Fe, Cu, Zn, Ga, Cd, Pb, Be, Ti, As, Bi, Sn, Sr, Ba, Tl, Co, and Ni were among the measured metals. The detail of the dilute acid solution preparation is reported in our previous study [34 (link)]. Inductively coupled plasma-mass spectrometry (iCAP TQ ICP-MS, Thermo Scientific, Waltham, Massachusetts, United States) was then used to measure the metals in the solution.

All ICP-MS experiments in this study were performed using the triple quadrupole instrument iCAP TQ ICP-MS (Thermo Fisher Scientific, Bremen, Germany) in single quadrupole (SQ) mode for ¹⁹⁵Pt⁺ monitoring. For phosphorous measurements, the formation of ³¹P¹⁶O⁺ was achieved by pressurizing the cell with O₂. For the chromatography experiments (required for the characterization of the particles) as well as for Pt measurement in DNA, the ICP-MS was fitted with a cyclonic spray chamber and a conventional concentric nebulizer.

Samples of the complex prepared as described in the ‘Protein expression and purification’ paragraph were injected onto Superdex® 200 Increase 10/300 GL column (Cityva) preequilibrated with the buffer devoid of molybdate: 20 mM Bis-Tris-HCl pH 7.0, 50 mM NaCl, 10 mM KCl, 10 mM MgCl₂ and 2 mM BME. The separation was performed using Äkta Pure protein purification system (Cityva) operating at 4 °C. The 0.5 ml protein fractions were pooled, concentrated using Amicon® Ultra-4 with the molecular weight cut-off 100 kDa (Millipore), flash-frozen in liquid nitrogen and stored at −80 °C. For the analysis, 100 μl of sample were diluted in 1% HNO₃ (v/v) in order to obtain a final solution of 10 ml. Trace element concentrations were determined with the Thermo Scientific iCAP TQ ICP-MS (using the Kinetic Energy Discrimination mode and He as collision gas on the “Plateforme AETE-ISO, OSU OREME, Université de Montpellier-France”). An internal solution, containing Be, Sc, Ge, Rh and Ir was added on-line to the samples to correct signal drifts. A calibration curve including four points (0, 1, 5 and 10 ppb) was analysed every 20–30 samples. The quality of the Mo analysis was checked by analysing international certified reference waters (CNRC SLRS-6). The accuracy was better than 10% relative to the certified values and the analytical error (relative standard deviation) was better than 3%.