Hpr 1000 6 m high pressure reactor

The pharmacokinetics
of intravenously administered Gd-L1 and ProHance were assessed by
ICP-MS quantification of the Gd content in plasma. For this purpose,
after the intravenous injection of 0.15 mmol/kg of Gd-L1 or ProHance
to healthy mice (n = 3), blood was collected from
mice tail veins at variable time points (t = 5 min,
10 min, 15 min, 30 min, 1 h, and 4 h). Before ICP-MS analysis, blood
samples were digested with concentrated HNO₃ (70%) under
microwave heating (Milestone MicroSYNTH Microwave laboratory station,
Balgach, Switzerland, equipped with an optical fiber temperature control
and HPR-1000/6 M high-pressure reactor, Milestone, Bergamo, Italy).
After the digestion, 3 mL of ultrapure water was added to each sample.
The specimens were then subjected to ICP-MS analysis (Element-2; Thermo-Finnigan,
Rodano (MI), Italy) to measure the concentration of Gd with respect
to standard curves. Results were reported as the Gd micromolar concentration
as a function of collection time.

At the end of the MRI experiments, the animals were sacrificed by cervical dislocation, in agreement with ethical rules. Cancer tissues, kidneys, liver, spleen, and muscles were explanted, weighed, and processed for ICP-MS analysis [53 (link)]. The tissues were added to 1 mL of concentrated HNO₃ (70%). Upon dissolution of the tissues, samples were further digested through microwave heating (MicroSYNTH, Microwave labstation, Microsynth, Balgach, Switzerland, equipped with an optical fiber temperature control and HPR-1000/6M high-pressure reactor, Milestone, Bergamo, Italy). After digestion, ultrapure water was added to each sample up to a 2 mL total volume, then samples were filtered with 0.45 μm filter and analyzed using ICP-MS for quantification of Gd³⁺, using a Thermo Scientific ELEMENT 2 ICP-MS-Finnigan, Rodano, Italy. A calibration curve obtained by using four gadolinium absorption standard solutions (Sigma-Aldrich, Burlington, MA, USA) in the range 0.005–0.1 μg/mL was used for the quantification. The total mass of Gd³⁺ retained in each specimen was calculated with respect to the weight of the tumor tissue (as μg of Gd³⁺/g of tissue).