Determination of Benzene in some Beverages under certain conditions

 

Nagham Makhoul¹*, Joumaa Al-Zohouri²

¹Master Student, Department of Food Control and Analytical Chemistry, Faculty of Pharmacy, Damascus University, Al-Mazzeh Street, Damascus, Syria

²Prof of Pharmaceutical and Analytical Chemistry, Faculty of Pharmacy, Damascus University

 

ABSTRACT:

In this study, benzene levels was determined in several beverage containing benzoate salts and ascorbic acid and which were exposed to high temperature and UV light. The samples were analyzed using a headspace gas chromatography-mass spectrometry technique HS-GC-MS. The benzene was detected in a number of samples, but the percentage did not exceed the authorized global values.

 

 

 

INTRODUCTION:

Soft drinks and non-carbonated beverages are commonly used in the local market and the global market in general. Benzene is formed in beverages which containing both benzoate salts and ascorbic acid by decarboxylation  of benzoate under certain conditions. Light, high temperature and metallic ions can catalyze this reaction^1,2.

 

Benzene is a human carcinogen, according to the International Agency for Research on Cancer (IARC)³. Chronic exposure causes blood disorders, especially in bone marrow⁴.

 

Every person is exposed every day to a small amount of benzene from the surrounding environment, workplaces or even at home.

 

The polluted air through cigarette smoke, engine smoke and emissions from industrial activities is the main source of exposure to benzene. Food, beverages and drinking water are other sources of exposure, either through pollution or through certain reactions that result in benzene formation^2,4

 

The objective of this study was to determine the levels of benzene in several beverages containing benzoate salts and ascorbic acid under certain conditions.

 

MATERIAL AND METHOD:

Instrumentation:

Gas Chromatography with MS detector (Agilent technology) in the headspace sampler mode.

 

Column: HP5 capillary column (30m×250µm ×0.25µm), Agilent technology

 

Chemicals and Reagents:

water for chromatography, (HPLC) grade methanol was purchased from merck, benzene standard(≥ 99,9%) was purchased from Sigma Aldrich.

 

Sampling:

samples were collected from the beverages available in the local market in the Syrian Arab Republic, which contained sodium benzoate and ascorbic acid, exept one sample that contained ascorbic acid only.

 

Sample Storage:

The study was applied on five products: A, B, C, D, E.

These five products were exposed to three conditions: 

First group (A1, B1, C1, D1, E1): samples were storaged at room temperature away from the sun light. 

Second group (A2, B2, C2, D2, E2): samples were storaged at high temperature (60ºC for 24 hour).

Third group (A3, B3, C3, D3, E3): samples in this group were exposed to UV light with wavelength 254 nm for 140 hours.

Preperation of benzene standard solution:

Benzene stock standard (about 2.2 mg/ml) was prepared by transferring with a syringe 50μL of neat benzene into 20 ml of methanol. Intermediate standard (54µg/ml) was prepared by transferring with a syringe 0.5 ml from stock standard into 20 ml of methanol. Benznene working standard was prepared from intermediate standard with concentration of 2.19µg/ml by appropriate dilution.

 

 

 

 

 

Analytical procedure:

The samples were analyzed using a modified and validated HS-GC-MS technique⁵. The HS sampler was programmed for a 15 min thermal equilibration at 75^ºC. The GC injector temperature was 220ºC with a 2:1 split ratio. The GC oven was ramped 5^ºC/min from 40 to 250 ºC and held for 5 min. The retention times for benzene was 2.44 min. The MS parameters were electron impact in the select ion mode.The ions monitored were m/z 78. A 10 mL test portion of each sample was transferred to a 20 mL HS vial, fortified with 5 µl of benzene standard 2.19µg/ml (standard addition). and then analyzed by HS GC/MS.

 

RESULT:

Figure 1 and 2 showed the chromatogram of D2 and A3 samples, respectively.

Table 1, 2 and 3 showed the results of the three groups.

 

 

Table 1: Results of first group

Sample number	A1	B1	C1	D1	E1
Peak area before standard addition	Nd	nd	nd	nd	nd
Concentration ppb	____	____	____	____	____
Peak area after standard addition	1048551	1052311	1061710	1014714	1053251
Concentration ppb	1.086	1.09	1.1	1.05	1.091

 

 

Table 2: Results of second group

Sample number	A2	B2	C2	D2	E2
Peak area before standard addition	Nd	nd	nd	431956	nd
Concentration ppb	____	____	____	0.43	____
Peak area after standard addition	1065470	1058138	1057311	1479979	1057010
Concentration ppb	1.104	1.0962	1.09532	1.545	1.095

 

 

Table : Results of third group

Sample number	A3	B3	C3	D3	E3
Peak area before standard addition	615243	nd	Nd	nd	nd
Concentration ppb	0.625	____	____	____	____
Peak area after standard addition	1649167	1067350	1059830	1065470	1057010
Concentration ppb	1.725	1.106	1.098	1.104	1.095

 

 

 

Fig 1: Chromatogram of D2 sample.

 

Fig 2: Chromatogram of A3 sample.

 

DISCUSSION:

Table 2 and 3 showed that higher amounts of benzene formed as a result of exposure to UV light rather than heating samples in a 60 ºC oven, but the percentage did not exceed the WHO guidline of 10 µg/l, EPA guidline of 5 µg/l and EU guidline of 1 µg/l ^6,7.

 

No benzene was detected in the benzoate free sample under all applicable conditions.

It can be explained by varying the values the samples, which exposed to same conditions to nature of water used in manufacturing and existence of elements stimulate oxidative stress (iron an manganese) in process water and storage of product after production and before test upon nature of materials and added flavor to product⁸.

 

CONCLUSIONS:

This study showed that the HS-GC-MS technique is an easy and rapid method to investigate the presence of benzene and determine its concentration in samples. It’s also showed that keeping beverages in a cool place away from the sun light (UV light) protect them from benzene formation, while exposure to UV light and high temperature during shelf life is considered a factor that stimulates benzene production. Therefore it’s consider that provide appropriate conditions over the shelf life of beverages is very important to minimize the risk of benzene formation

 

CONFLICT OF INTEREST:

The authors declare no conflict of interest.

 

 

 

REFERENCE:

1.     Food and Drug Administration. U.S. Code of Federal Regulations, Part 184, Section 184.1021, Title21. 2008a

2.     Gardner, L.K.and Lawrence, G.D. Benzene Production from Decarboxylation of Benzoic Acid in the Presence of Ascorbic Acid and a Transition-Metal Catalyst. J. Agric. Food Chem. 1993, 5: 693–695.

3.     IARC. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans; A Review of Human Carcinogens,100, Lyon, France, 1998

4.     Toxicological Profile for Benzene; Division of Toxicologyand Environmental Medicine Agency for Toxic Substances and disease registry,Public Health Services, U.S. Department of Health and Human Services, Atlanta GA, 2007.

5.     Nyman  J.P., Wamer G.W., Begley H.T., Diachenko W.G. and Perfetti A.G. Evaluation of Accelerated UV and Thermal Testing for Benzene Formation in Beverages Containing Benzoate and AscorbicAcid . Journal of food science. 2010, 75: 263-267.

6.     World Health Organization. Guidelines for drinking-water quality, 2nd ed. 2,  Geneva, 1996

7.     Council Directive 98/83/EC on the quality of water intended for  human consumption. 3 November 1998.

8.     Morsi M.Y.R., EL-Tahan N.R. and EL-Tobgy K. Probability of Benzene Forming in Egyptian Non-Alcohol Carbonated Soft  Drinks. Australian Journal of Basic and Applied Sciences. 2012; 6(3): 271-278.

 

 

 

Accepted on 17.07.2018        © RJPT All right reserved

Research J. Pharm. and Tech 2019; 12(1): 37-39.