Butan 1 ol

Plasma, platelet, and WB samples underwent the sample dilution method described below for the subsequent ICP-MS analysis, while pRBCs were previously mineralized by mixing 400 µL of pRBCs with 800 µL of pure nitric acid (RPE analytical grade 69.5%, Carlo Erba Reagents, Cornaredo, Italy) at 70 °C for 1 h. After homogenization, samples were diluted in a nitric acid (RPE analytical grade 69.5%, Carlo Erba Reagents) solution in ultrapure water (Purelab Flex, Veolia Water, Paris, France) containing either (i) Triton^TM X-100 (Sigma-Aldrich, St. Louis, MO, USA) and butan-1-ol (VWR chemicals, Radnor, PA, USA) for Pb and Cd analysis or (ii) hydrochloric acid (Suprapur 30%, Supelco, Bellefonte, PA, USA) and gold (Supelco) for Hg analysis.
The analysis was performed on a THERMO ICAP^TM Qc ICP-MS (Thermo Scientific, Waltham, MA, USA). Quantification was performed by external calibration using rhodium (¹⁰³Rh) as the internal standard. For plasma, platelets, and WB, the lower limit of quantification (LLOQ) was 0.2 µg/L. For pRBCs, the LLOQ was multiplied by 3 according to the sample dilution during mineralization: 0.6 µg/L [30 ].
The analytical methods were monitored daily by internal quality controls (reference materials) as well as successful participation to the QMEQAS external quality assessment scheme from the Quebec National Institute of Public Health for several years.