*2.3.2 Aluminum quantitative analysis method*

Local kitchen utensil samples have been thoroughly washed and rinsed using distilled water then air dried. Each kitchen utensil has been filled out with studied solution WS and WR then heated at boiling temperatures. To compensate evaporation during heating phase, the final volume is adjusted to the end of each operation with distilled water [12].

### *2.3.3 Colorimetric dosage of aluminum released from local kitchen cooking*

The loss of aluminum quantity released from two local kitchen utensils was determined by colorimetric dosage to 5 ml sample for each cooking solution. For that it was placed in the graduated flask of 50.0 ml containing 10.0 ml distilled water: 5.0 ml of EBT solution, 20.0 ml of buffer solution acetyl acetic acid (C4H6O3) permit to hold a pH at 6; 1.0 ml ascorbic acid 2% and a volume of solution S0 specified in **Table 2** then filled up to the line of gauge with distilled water. After stirring and resting during 20 minutes, samples were analyzed with spectrophotometer. The standard was measured with a solution without aluminum and tally with no absorbance. The concentration of aluminum in the different solution was expressed in mg/L.

#### **2.4 Data analysis**

Data obtained were analyzed for duration and temperature variations using the Student's t-test and XLSTAT 7.5.2 statistical software. Mean parameter concentrations were compared according to the Ryan-Einot-Gabriel-Welsch (REGWQ ) test.

### **2.5 EIS-electrochemical impedance techniques**

Electrochemical impedance spectroscopy (EIS) is a well-established quantitative method for the accelerated evaluation of the anti-corrosion performance of


#### **Table 2.**

*Composition of standard scale.*

protective coatings. Within short testing times, EIS measurements provide reliable data, allowing for the prediction of the long-term performance of the coatings. The result of EIS is the impedance of the electrochemical system as a function of frequency. EIS is a versatile testing procedure and can be performed under different conditions of stress, depending on the performance of the tested coatings. Electrochemical impedance spectroscopy (EIS) is a powerful technique that utilizes a small amplitude, alternating current (AC) signal to probe the impedance characteristics of a cell. The AC signal is scanned over a wide range of frequencies to generate an impedance spectrum for the electrochemical cell under test. EIS differs from direct current (DC) techniques in that it allows the study of capacitive, inductive, and diffusion processes taking place in the electrochemical cell.

### **2.6 Electrochemical measurements**

The electrochemical measurements were conducted in the Analytical Chemistry and Interfacial Chemistry (CHANI) of the University of Brussels (ULB). The EIS measurements were determined in a three electrodes electrochemical cell containing the culinary media. There are three electrodes – the reference electrode, the auxiliary electrode, and the working electrode. A saturated calomel electrode (SCE) was used as the reference electrode, a platinum metal gate as the auxiliary electrode, and a recycled aluminum alloy as working electrode (WE) made in the laboratory. The EIS measurements were performed with employed Princeton Applied Research potentiostat (model PGSTAT 50). A microcomputer was used for data acquisition. The measurements were carried out after 60 minutes of cooking.
