Traditional Calibration Methods in Atomic Spectrometry and New Calibration Strategies for Inductively Coupled Plasma Mass Spectrometry

Abstract

Applications, advantages, and limitations of the traditional external standard calibration, matrix-matched calibration, internal standardization, and standard additions, as well as the non-traditional interference standard method, standard dilution analysis, multi-isotope calibration, and multispecies calibration methods are discussed.

Keywords: interference standard method; internal standardization; matrix-matched calibration; multi-isotope calibration; multispecies calibration; standard additions; standard dilution analysis.

Figure 1

SA calibration plot using four addition points (x₁-x₄). Extrapolation is represented by a broken line, and x₀ is the sample with no standard addition.

Figure 2

Calibration plot used to determine Si in a 1% v/v HNO₃ matrix by ICP-QMS (m/z = 28). No collision/reaction gas was used.

Figure 3

Calibration plot used to determine Si in a 1% v/v HNO₃ matrix by ICP-QMS (m/z = 28) using the IFS method. The ³⁸Ar⁺ ion was used as IFS species, and the analyte-to-IFS signal ratio was plotted on the y-axis. No collision/reaction gas was used.

Figure 4

SDA plot for the determination of Ba and Cu in Oyster Tissue (NIST 1566b) by ICP-MS. Yttrium was used as internal standard, and He flowing at 3.5 mL/min was used in the collision/reaction cell.

Figure 5

Calibration plots created from the SDA region (negative slopes) in Figure 4. The concentrations of Ba, Cu, and Y added to S1 were 50 μg/L each.

Figure 6

MICal plot used to determine Cd in a tap water sample spiked with 10 μg/L of the analyte. The concentration of Cd standard added to S1 [C(A)_Std] was 30 μg/L. He flowing at 3.5 mL/min was used in the collision/reaction cell.

Figure 7

MICal plot used to determine Cd in a tap water sample spiked with 10 μg/L of the analyte. S1 and S2 were prepared with 70% of sample and 30% of standard solution or blank. The concentration of Cd standard added to S1 [C(A)_Std] was 30 μg/L. He flowing at 3.5 mL/min was used in the collision/reaction cell.

Figure 8

Summary of the most adequate general applications for EC, IS, SA, IFS, SDA, MICal, and MSC.