Indirect determination of the flavor enhancer maltol in foods and beverages through flame atomic absorption spectrometry after ultrasound assisted-cloud point extraction

- A mixed micellar enhanced extraction method was developed prior to indirect analysis.
- The method is based on reduction of Cu(II) with maltol in presence of bathocuproine at pH 6.5.
- Bathocuproine binds selectively Cu(I) produced, which is linearly related to maltol concentration.
- Ultrasonic energy was used to facilitate and enhance the extraction process.
- The method is sensitive enough to detect 1.24 μg L−1 of maltol in selected sample matrices.
- This method can be used as a detection tool for low levels of maltol in complex matrices.

A simple ultrasound assisted-cloud point extraction (UA-CPE) method was developed and combined with flame atomic absorption spectrometry (FAAS) for pre-concentration and indirect determination of the flavor enhancer maltol in foods and beverages. The method is based on reduction of Cu(II) to Cu(I) by maltol at pH 6.5, and subsequent selective interaction of Cu(I) with bathocuproine (BCP) to form a ternary complex in presence of sodium dodecyl sulfate (SDS). Under the optimized conditions, pre-concentration of a 35 mL sample solution allowed detection of 1.24 µg L−1 maltol in a linear range of 4-230 µg L−1. The method was validated by intra- and inter-day precision studies ranging from 2.1 to 3.4%, and recoveries ranged from 93.3% to 104.4% using standard addition method. After pretreatment with two different sample preparation steps assisted by ultrasound energy, the proposed method was applied successfully for determination of maltol in selected foods and beverages.