**6. Conclusion**

224 Food Industrial Processes – Methods and Equipment

5 6 7 8 910

**pAsO3, p(mol L-1)**

1) 0.2 mmol L-1; 2) 0.4 mmol L-1; 3) 0.6 mmol L-1; 4) 1 mmol L-1; 5) 1.2 mmol L-1. pAsO3 is the

H3AsO3 + I3- + H2O = H3AsO4 + 3I +2H+ The sensitivity of the determinations, as shown in Table 2, increased with the increase of the acetylthiocholine iodide concentration until the enzyme saturation with 1.0 mmol L-1

**Substrate concentration, mmol L-1 Sensitivity, A/p(mol L-1)**  0.2 0.39 0.4 0.65 0.6 1.25 1.0 1.65

The method allows As(III) and As(V) differentiation, due to the fact that AsO43- does not

These preliminary results served for the development of a method for As(III) determination in wine. As known, arsenic content in some type of wines exceeds 0.1 mg L-1 (Crecelius, 1997). Arsenic concentration in contaminated illicit whiskey (moonshine) was found to be

For the purposes of the analysis, commercially available wine was artificially contaminated with AsO33- 0.0133 mmol L-1 (0.001 mg L-1). The sample, without any pretreatment, was analysed according to the following protocol: (i) registration of the amperometric response of the electrochemical biosensor for a substrate concentration of 1.0 mmol L-1, for which the

pH 7, 1000 rpm, +0.80 V/SCE) in the presence of no contaminated wine; (ii) registration of the amperometric response of the electrochemical biosensor in similar conditions, but in the presence of the contaminated wine sample; (iii) I calculation and AsO33- concentration

3- determination is maximal (25oC, Britton-Robinson buffer 0.1 mol L-1,

3- concentration. As shown, the linear dynamic range of the calibration curves suitable for AsO33 determinations varies from 0.2 nmol L-1 to 0.02 mol L-1. AsO33- concentrations superior to 10 mol L-1 caused an increase of the sensor response, due to the following concurrent

3- determination using different substrate concentrations:

 -2e- = I3 -

0

acetylthiocholine iodide.

Fig. 2. Calibration curves for AsO3

negative decimal logarithm of the AsO3

Table 2. Sensitivity of As(III) determination

more than 0.4 mg L-1 (Gerhardt et al., 1980).

inhibit the acetylcholinesterase.

sensitivity of the AsO3

3I-

10

 

reactions:

20

The modern food analysis requires sensitive, accurate, and express methods for food safety, food quality, and food technology control. The growing field of the biosensors in food industry represents an answer to this demand. Thus, the method for As(III) determination in wine described in this work is an example demonstrating the viability of the electrochemical biosensors in food quality control.
