Bismuth as a general internal standard for lead in atomic absorption spectrometry

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Science

Background:

• Accurate determination of lead (Pb) is crucial in various matrices.
• Matrix effects can significantly impact the accuracy of Pb measurements.
• Internal standardization is a common technique to compensate for such effects.

Purpose of the Study:

• To evaluate bismuth (Bi) as an internal standard (IS) for lead (Pb) determination.
• To assess the performance of Bi as an IS across different atomic absorption spectrometry techniques.
• To improve the accuracy and precision of Pb analysis in complex samples.

Main Methods:

• Lead determination using line source flame atomic absorption spectrometry (LS FAAS).
• Lead determination using high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).
• Lead determination using line source graphite furnace atomic absorption spectrometry (LS GFAAS).
• Bismuth was employed as the internal standard, with calibration curves plotted as absorbance ratios (A(Pb)/A(Bi)) versus Pb concentration.

Main Results:

• Close correlation observed between Pb and Bi absorbances across different matrices.
• High correlation coefficients (>0.9953 for FAAS, >0.9993 for GFAAS) achieved with Bi as IS.
• Significant improvements in Pb recovery rates (e.g., 52-118% to 97-109% for LS FAAS).
• Marked reduction in relative standard deviations (e.g., 0.6-9.2% to 0.3-4.3% for LS FAAS).

Conclusions:

• Bismuth is a suitable and effective internal standard for lead determination by FAAS and GFAAS.
• Using Bi as an IS enhances the accuracy and precision of Pb measurements, particularly in samples with varying matrices.
• This approach offers a reliable method for improving the quality of lead analysis in environmental and industrial applications.