Water chemistry of seven lakes in Belarus and Ukraine 2014 to 2016

After filtration on a 0.2 micrometre mesh size filter and acidification (2% v/v of HNO3 65% trace metal grade, Sigma), major alkali and alkali-earth element water concentrations (Na, Mg, S, K and Ca in mg/L, mean ± SD, n = 3 per lake) and trace elements concentrations (As, Sr, Cd, Cs, Pb and U in micro g/L, mean +/- SD, n = 3 per lake) were measured in the 7 lakes with quadrupole-based ICP-MS system (Model iCAPQ; Thermo Scientific) equipped with CCTED, ‘collision cell mode’ (7% Hydrogen in Helium) with kinetic energy discrimination (KED) to eliminate polyatomic interferences. Samples entered the ICP-QMS through an auto-sampler (Cetac ASX-520) via a nebuliser (Thermo-Fisher Scientific; 1mL min-1) and spray chamber. Internal standards were introduced to the sample stream via a separate line including Ge (50 micro g/L), Rh (20 micro g/L) and Ir (10 micro g/L) in 2% HNO3. Two sets of external mulit-element calibration standards for major elements (0-30 mg/L) and trace elements (0-100 micrograms per litre) were prepared from Certiprep(TM) multi-element stock solutions. After filtration on a 0.45 micrometre mesh size filter and preservation (1% v/v of ZnCl2 50% w/v), concentrations of inorganic macronutrients (NO3-, NO2- and PO43- in μg/L, mean +/- SD, n = 3 per lake) were determined using a QuAAtro segmented flow nutrient analyser with autosampler (SEAL Analytical, UK). Analysis was done according to standard procedures.