The accurate determination of major and trace elements in seawater using ICP-OES

This study aimed to develop a method for the determination of major elements (potassium, calcium, sodium, magnesium, sulfur, chlorine) in seawater using inductively coupled plasma optical emission spectrometry (ICP-OES). The method involved dilution of seawater and optimized suitable sensitive and interference-free emission lines (K 766 nm, Ca 317 nm, Na 589 nm, Mg 285nm, S 181 nm, Sr 407 nm, and B 249.7 nm). The detection limits (3σ) were measured as 1.34mg/L for K, 1.0 mg/L for Ca, 1.1 mg/L for Na, 1.0 mg/L for Mg, 2.1mg/L for S, 0.80µg/L for Sr and 0.5 mg/L for B, respectively. This method consistently produced high precision results, with the RSD of seawater samples being less than 3.06%. Furthermore, the recoveries of K, Ca, Na, Mg, and Sr ranged from 97–103%. Although the recoveries of S and B varied more widely (S recovered at a rate of 97–105%, while B recovered at a rate of 90–111%), both were found to meet the test requirements for this magnitude. Overall, this method offers advantages such as simplicity of operation, high determination efficiency, and good data stability and test precision, which make it suitable for high-precision and high-accuracy tests for K, Ca, Na, Mg, S, Sr, and B in seawater.