Nitric acid

All reagents were of analytical grade. Milli-Q water (Millipore) was used throughout the experiment. Trizma^® HCl and Trizma^® Base were purchased from Sigma (St. Louis, MO, USA). Nitric acid, ammonium acetate, acetic acid, 28% ammonia solution, L-cysteine, sodium arsenite (iAs^III), sodium arsenate (iAs^V), and dimethylarsinic acid [(CH3)2AsO(OH)] (DMA^V) were purchased from Wako Pure Chemical Industries, Ltd. (Osaka, Japan). Monomethylarsonic acid (MMA^V) was obtained from Tri Chemicals (Yamanashi, Japan). The arsenic standard solution (1, 000 μg/mL) for ICP-MS was purchased from SPEX CentiPrep (Metuchen, NJ, USA). Stock solutions of all arsenic compounds (10 mmol/L) were prepared from the respective standard compounds. All stock solutions were stored in the dark at 4°C. Diluted standard solutions for analysis were prepared daily prior to use.

Cisplatin was purchased from Wako Pure Chemical Industries Co., Ltd. (Tokyo, Japan). Egg phosphatidylcholine (EPC, Coatsome^® NC-50) and Tween 80 were products of NOF Inc. (Tokyo, Japan). Sodium Deoxycholate (SD) was acquired from Wako Pure Chemical Industries Co., Ltd. (Osaka, Japan). Sodium cholate (SC) was supplied by Sigma Aldrich (Tokyo, Japan). The diblock polymer used in this experiment was polyethylene oxide-b-polymethacrylic acid (PEO-b-PMAA; M_w of PEO = 7500; M_n of PMAA= 11 000) was obtained from Polymer Source, Inc. (Canada). Saline was purchased from Otsuka Co. Ltd. (Japan). In order to undertake high-performance liquid chromatography (HPLC) analysis, all solvents were of HPLC analytical grade. For graphite furnace atomic absorption spectrophotometry (GF-AAS) measurements, nitric acid (1.38; analytical grade, Wako Pure Chemical Industries Co., Ltd., Osaka, Japan) was employed as a digestive acid solution, while hydrochloric acid (AAS analytical grade) was used for the sample solvent (Kanto Chemical Co., Inc., Tokyo, Japan). The solvents; ethanol, methanol, acetone, and chloroform; were purchased from Wako Pure Chemical Industries, Ltd. (Osaka, Japan). All other reagents and solvents employed in this study were of the highest quality available. Milli-Q water was used in all experiments.

Pyrogallol (C₆H₃(OH)₃, > 99%), sodium citrate hydrate (C₆H₅Na₃O₇·2H₂O, > 99%), polyvinpyrrolidone (PVP, > 99%), methanol (CH₃OH, > 99.8%), sodium hydroxide (NaOH, > 97%), potassium hydroxide (KOH, > 85%), lead (II) nitrate (Pb(NO₃)₂, > 99.9%), and nitric acid (HNO₃, 69%) were purchased from Wako Pure Chemical Industries, Ltd. All chemical were used as received without further purification. Deionized water with a specific resistance of 18.2 MΩ cm was obtained by reverse osmosis followed by ion exchange and filtration.

Blood samples were collected from the participants from antecubital veins under the fasting condition. Serum separation was performed by centrifugation at 1000× g for 10 mins. Samples were stored at −80 °C until the laboratory experiments. In this study, we assessed the hematological parameters of hemoglobin, packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and total red blood cells (RBC) counts. Compositions of blood were measured using an automated blood analyzer (Sysmex SE9000, Kobe, Japan).
Serum trace elements concentrations of Cd, Zn, Co, Cu and Se were measured using quadrupole, inductively coupled plasma mass spectrometry (ICP-MS) (SCIEX, ELAN6000, PerkinElmer Inc., Waltham, MA, USA). To prevent the contamination and disturbance, all the laboratory equipment in the trace elements measurement were washed with 15% nitric acid (Wako, Japan). The samples were measured against the multielement standard solution (TraceCERT, Sigma-Aldrich, LLC) by means of calibration curve. The measurements were externally validated against the certified reference material (Seronorm Trace Elements Serum L-1, Sero, Norway). All the values of trace elements measurements were within the acceptable ranges.