Arium pro water purification system

Purified water (18.2 MΩ cm at 25 °C, 0.22 μm filtered) was obtained from a Sartorius arium® pro water purification system. 3M™ Novec™ 7500 Engineered Fluid [42 ] is a fluorinated heat transfer oil that was used as the continuous phase for generating droplets, and was purchased from Fluorochem Ltd. (Hadfield, UK). Pico-Surf™ 1 (5% w/w in Novec™ 7500 oil) is a fluorinated surfactant [43 (link),44 ] used for stabilising the droplets, which was purchased from Sphere Fluidics Ltd. (Cambridge, UK) and further diluted to 2% w/w in Novec™ 7500 oil for experiments. Silicone oil, used to form an interface between the microfluidic plate and the cold stage platform to improve heat transfer, was purchased from Sigma-Aldrich (Dorset, UK). Polydimethylsiloxane (PDMS, Dow Corning® Sylgard® 184 Kit) was purchased from Ellsworth Adhesives (East Kilbride, UK).

LQ, LA, ILQ, ILA and GA were purchased from Sichuan Weikeqi Biological Technology Co., Ltd. (Chengdu, China), and their structures are shown in Fig. 1. Their purities were above 95% according to HPLC-UV analysis. All ionic liquids ([C₂MIM]Br, [C₄MIM]Ac, [C₄MIM]Cl, [C₄MIM]BF₄, [C₄MIM]NO₃, [C₄MIM]HSO₄, [C₄MIM]Br, [C₆MIM]Br, [C₈MIM]Br and [C₁₀MIM]Br, where C₂MIM = 1-ethyl-3-methylimidazolium, C₄MIM = 1-butyl-3-methylimidazolium, C₆MIM = 1-hexyl-3-methylimidazolium, C₈MIM = 1-octyl-3-methylimidazolium, C₁₀MIM = 1-decyl-3-methylimidazolium) were gained from Chengjie Chemical Reagents Co., Ltd. (Shanghai, China), and their structures are shown in Table S1.† HPLC grade methanol, acetonitrile and formic acid were obtained from Mallinkrodt Baker (Phillipsburg, NJ, USA), and de-ionized water was acquired by an arium pro-water purification system (Sartorius, Göttingen, Germany). All the other reagents were obtained commercially.
The scanning electron microscope (SEM) pictures, used to evaluate the morphology of the licorice powder after extraction, were acquired using a field emission gun Hitachi S-4800 scanning electron microscope with a 5 kV acceleration voltage (Hitachi Co. Ltd., Tokyo, Japan).

Polypropylene 10 mL tubes with high-density polyethylene screw caps (Ref# 62.9924.284) used for sample digestions were from Sarstedt (Nümbrecht, Germany). Nitric acid (HNO₃, TraceSELECT™, ≥69.0%) and hydrochloric acid (HCl, TraceSELECT™, ≥30%) were purchased from Honeywell Fluka™ (Düsseldorf, Germany). For ICP-MS determinations, the multi-element standard solution TraceCERT^® (100 mg/L), ICH Q3D oral, Standard 2 solution from Merck KGaA (Darmstadt, Germany) and the internal standard solution ICP-MS-200.8-IS-1 (100 mg/L of Sc, Y, In, Tb, Bi) from AccuStandard^® (New Haven, CT, USA) were used. Ultrapure water (18.2 MΩ.cm at 25 °C) was obtained with an Arium^® pro water purification system (Sartorius, Goettingen, Germany). Animals were euthanized with Euthasol^® solution (400 mg/mL pentobarbital sodium) acquired from Le Vet (Oudewater, The Netherlands). Cisplatin (cis-dichlorodiammine platinum(II), 99.9%), potassium tetrachloropalladate (II) (K₂PdCl₄, 98%), spermine (N,N’-bis(3-aminopropyl)-1,4-diaminobutane, 99%), DMEM-HG cell culture medium and RPMI-1640 cell culture medium were purchased from Sigma-Aldrich (Sintra, Portugal). Fetal bovine serum (FBS) was from Gibco (Thermo Fisher Scientific, Inc., Waltham, MA, USA). All the other reagents were of analytical grade.

All solutions were prepared with ultrapure water (>18.2 MΩ·cm at 25 °C) obtained with a Sartorius Arium^® pro water purification system (Gottingen, Germany). Nitric acid (HNO₃, 67–69% w/w TraceMetal^® Grade) was obtained from Fisher Scientific (Leicestershire, UK). Triton X-100, butanol (>99.0%) and multi-element stock solutions (10 mg/L) Periodic Table Mix 1, 2 and 3 were obtained from Sigma-Aldrich (St. Louis, MO, USA). Copper and Zn single-element stock solutions (1000 mg/L) were obtained from SCP Science (Quebec, QC, Canada). All laboratory ware (bottles, tubes, volumetric flasks) was made of polypropylene or high-density polyethylene (HDPE) and was properly decontaminated by immersion in a 10% v/v HNO₃ solution for at least 24 h, followed by abundant rinsing with ultrapure water and drying at room temperature under dust-free conditions.

Aqueous solutions were prepared with ultra pure water (maximum conductivity of 0.055 μS cm^-1) produced by a Sartorius arium pro water purification system (Goettingen, Germany). McFarland turbidity standards were prepared by mixing aliquots of a 1% aqueous barium chloride (Fluka, Buchs, Switzerland) with 1% sulphuric acid (Fisher Scientific, Waltham, MA, USA). A stock solution of 1000 mg L^-1 of bromothymol blue (BTB) (Merck, Darmstad, Germany) was prepared from the dissolution of the solid dye in the appropriate volume of 0.1 mol L^-1 boric acid (Chem-lab, Zedelgem, Belgium) at pH 9.5. The BTB working standards were prepared by stepwise dilution of the stock solution using the same buffer as solvent.