Fast method of elements determination in slim coffees by ICP OES

Area of Science:

• Analytical Chemistry
• Food Chemistry
• Spectroscopy

Background:

• Slim instant coffee analysis requires efficient sample preparation for accurate elemental determination.
• Various methods exist for sample decomposition, each with advantages and limitations.

Purpose of the Study:

• To compare six different sample preparation procedures for elemental analysis in slim instant coffee.
• To identify the most effective method for determining a wide range of elements using ICP-OES.

Main Methods:

• Six procedures were evaluated: microwave-assisted digestion, hot-plate digestion, aqua regia solubilization, tetramethyl ammonium hydroxide solubilization, dilute nitric acid dissolution, and water dissolution.
• Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for elemental determination.
• Performance was assessed based on precision, accuracy, and limits of detection.

Main Results:

• Aqua regia extraction yielded the best results, with element detection limits from 0.11-108 ng/mL, precision of 0.6-5%, and accuracy better than 5%.
• Results from aqua regia extraction correlated well with those from wet digestion using nitric acid and hydrogen peroxide.
• The aqua regia method is a simple, fast, and reliable alternative for routine analysis.

Conclusions:

• Aqua regia extraction is a highly effective sample preparation technique for elemental analysis in slim instant coffee.
• This method offers a practical and efficient alternative to more complex decomposition procedures for routine quality control.