Excessive consumption of bromate-containing wheat flour and pasta products may cause cancer


Carcinogens may also be contained in flour? On May 30, 2005, the Ministry of Health issued the "Announcement No. 9 of 2005", prohibiting the use of a food additive called "potassium bromate" in wheat flour, which immediately caused a shock in the flour industry. It is reported that many domestic flour companies are still using potassium bromate as an additive.

In experiments conducted many years ago, Japanese and American scientists have discovered that potassium bromate is a carcinogen. Excessive consumption can damage the central nervous system, blood and kidneys. The International Agency for Research on Cancer has also listed this compound as a carcinogen. In fact, the World Health Organization recommended the ban on the use of potassium bromate several years ago, and European countries no longer use it.

Our company’s OIC-600 ion chromatograph has carried out a large number of experiments to determine the content of bromate in wheat flour. The conclusion of the experiment is that the ion chromatography has the characteristics of high sensitivity, faster speed, high accuracy, and wide linear range.

Determination of bromate in wheat flour and flour products-ion chromatography

Abstract: Potassium bromate is easy to decompose after being heated. As a flour strengthening agent, it has been widely used in the flour processing industry. Its role is to whiten, and to ferment the dough, which can make the bread looser and more beautiful. However, studies have found that excessive Consumption of bromate will greatly increase the incidence of kidney cancer, thyroid and peritoneal mesothelioma. Therefore, the International Cancer Research Center (IARC) classifies bromate as a 2B carcinogen. The Ministry of Health of my country has decided to cancel the use of potassium bromate as a flour treatment agent in wheat flour and flour products from July 1, 2005.

This paper establishes a method for detecting bromate in wheat flour by ion chromatography. The experiment uses ultrapure water to extract bromate in wheat flour and enters the ion chromatographic column for analysis after multiple filtrations. The test results show that when the bromate concentration is 0-6.0mg/L, the linear correlation coefficient reaches 0.9992. The standard recovery rate of bromate is between 85-120%. The method is fast and simple, and can quickly and accurately analyze trace amounts of bromate in wheat flour.

1. Experimental part

Experimental instruments: OIC-600 ion chromatograph (Beijing Hankeyao Instrument Co., Ltd.); conductivity detector; HW2000 universal version chromatographic workstation; Dionex IonPacTMAS23 chromatographic column; ultrasonic cleaner; centrifuge; pipette.

Experimental drugs: ultrapure water (conductivity <1.0 us/cm); sodium bromate (analytical purity); sodium carbonate (excellent grade pure); sodium bicarbonate (excellent grade pure); wheat flour (commercially available); Ag/H Column; RP column; 0.45μm filter membrane

Prepare bromate standard solution: Weigh 0.118g sodium bromate and 100mL constant volume, namely 1000mg/L BrO3- stock solution; pipette 10mL stock solution into a 100mL volumetric flask to constant volume, namely 100mg/L BrO3- Standard solution

BrO3-standard working curve: accurately pipette the standard solution 0mL, 0.5mL, 1.0mL, 1.5mL, 2.0mL, 2.5mL, 3.0mL to 50mL, the solubility of the standard working curve is 0mg/L, 1mg/L , 2mg/L, 3mg/L, 4mg/L, 5mg/L, 6mg/L. The injection volume is 100μL. If the injection volume is greater than 200μL, the standard solution should be appropriately diluted.

Column conditions

Eluent: 4.5mM Na2CO3 / 0.8mM NaHCO3

Temperature: 30℃

Flow rate: 1.0mL/min

2. Sample preparation

Extraction of bromate in wheat flour: accurately weigh 10.0g wheat flour into a 250mL Erlenmeyer flask, add 100mL water, and shake it evenly (lightly tap it, it won’t make a paste), ultrasound for 20min (intermittent shaking), stand still, transfer Centrifuge the 20mL supernatant in a 50mL centrifuge tube at 3000r/min for 20min, and the supernatant for use.

Purification: Activate the Ag/H column and the RP column, take the supernatant and pass it through the RP column, then the Ag/H column, discard the first 2 mL, collect the remaining effluent, and pass the 0.45μm membrane when injecting.

Standard addition recovery experiment: BrO3 of standard concentration was added to 10g wheat flour, processed according to the above-mentioned sample treatment, and then injected and analyzed.

3. Results and discussion

Passing wheat flour through RP column and Ag/H column can make Cl- and BrO3- meet the separation requirements. Bromate in the extract of wheat flour is less than 0.5mg/kg, which is regarded as undetected, as shown in Figure 2. It can be seen from the spectrum that there is almost no BrO3- in the wheat flour. BrO3- was detected in the spiked wheat flour extract, and the spiked recovery rate was 85-120%, as shown in Figure 3.

Calculation of BrO3- content:

C=Y*V/m

C——The content of BrO3- in the sample (mg/kg)

Y——Get the content of BrO3- in the sample solution from the standard curve (μg/mL)

V——Volume of sample solution (mL)

m——sample quality (g)



The standard liquid spectrum and standard working curve are as follows:



Figure 1. Standard working curve of BrO3-

Wheat flour spectrum:




Figure 2. Separation of wheat flour on Dionex IonPacTMAS23 column



Spectra of wheat flour after adding standard:

Figure 3. Separation of wheat flour on Dionex IonPacTM AS23 column when BrO3-1mg/kg is added

4 Conclusion

The OIC-600 ion chromatograph produced by Beijing Hankeyao Instruments has the characteristics of high sensitivity, faster speed, high accuracy, and wide linear range for the ion chromatography established in this paper for the determination of bromate in wheat flour.


references

National Standard of the People's Republic of China: "Determination of Bromate in Wheat Flour-Ion Chromatography. GB/T 20188---2006"