New Product Launch | Liquid Chromatography for the Detection of Benzo(

According to the new version of the “National Food Safety Standard for Contaminants in Food” (GB2762-2022) implemented in China on June 30, 2023:

There are mandatory limits for Benzo(a)pyrene in the following five categories of food according to the new regulations:

• Edible oils and their products: 10 μg/kg.
• Cereals and their products (such as wheat, flour, etc.): 2 μg/kg.
• Smoked and barbecued meat products: 5 μg/kg.
• Smoked and barbecued aquatic products: 5 μg/kg.
• Additionally, a new category of food has been introduced with maximum limits for Benzo(a)pyrene—dairy products including light cream, butter, and anhydrous butter. The maximum limit for Benzo(a)pyrene in this category is set at 10 μg/kg. This marks the first time in China that mandatory limits for Benzo(a)pyrene have been established for these three types of dairy products.

Currently, the detection of Benzo(a)pyrene in various food categories in China is primarily based on the existing “National Food Safety Standard for the Determination of Benzo(a)pyrene in Food” (GB5009.27-2016). The detection technique involves high-performance liquid chromatography (HPLC), and sample pretreatment techniques include neutral alumina column chromatography or molecular imprinting technology.

Due to the fact that the types of foods involved in Benzo(a)pyrene detection are mostly complex processed foods, the key to the success of the detection lies in how to separate, extract, and purify Benzo(a)pyrene from these highly complex food matrices.

The neutral alumina column chromatography technique

The neutral alumina column chromatography technique, one of the preprocessing methods specified in the Chinese national standard GB5009.27-2016 for the detection of Benzo(a)pyrene, is generally infrequently used. This is due to its intricate operation, significant consumption of organic solvents, and the substantial impact of filler material, loading method, and the proficiency of manual operation on the stability of detection results.

Molecular imprinting technology

One widely used preprocessing technique is molecular imprinting technology. Although molecularly imprinted columns exhibit good selectivity, their recovery is significantly influenced by the column flow rate. Generally, slower flow rates result in better recovery and stability, but this comes at the cost of longer processing times.

The stability between batches of molecularly imprinted columns is relatively poor, and there can be variations in adsorption characteristics among products from different batches. Therefore, it is essential to experimentally verify the performance of each batch of molecularly imprinted columns.

Moreover, molecularly imprinted columns have a limited purifying effect, especially for samples with complex matrices. After preprocessing, there may be a higher residue of fats and impurities, posing a risk of contaminating chromatographic columns and instruments.

Furthermore, it is crucial to note that the application scope of the 2016 version of the national standard does not include dairy products such as cream, and there is no sample preprocessing technique specified for cream and similar dairy products. We have verified that the two sample preprocessing techniques outlined in this national standard are not suitable for various types of cream and dairy products.

To address the technical challenges mentioned above, Welch Materials has developed a new product – a specialized sample preprocessing kit for the detection of Benzo(a)pyrene in food and feed using liquid chromatography. This kit, named BAP-04, is specifically designed for the preprocessing of samples from edible oils and their products, cereals and their products, grain feed, smoked and barbecued meat products, smoked and barbecued aquatic products, and dairy products (light cream, butter, and anhydrous butter).

This method package employs Solid-Phase Extraction (SPE) technology for the preprocessing of samples to separate, extract, and purify Benzo(a)pyrene before quantification using liquid chromatography. It is designed for determining the content of Benzo(a)pyrene in various types of food, cereals, and grain feed using liquid chromatography.

This specialized sample preprocessing kit has several key advantages:

1. Broad Applicability: It is applicable for the sample preprocessing of a wide range of samples, including edible animal and plant oils (both liquid and solid), cereals and their products, grain feed, smoked and barbecued meat products, smoked and barbecued aquatic products, and dairy products (light cream, butter, and anhydrous butter). Its scope not only covers all food categories with mandatory limits for Benzo(a)pyrene specified in the latest “National Food Safety Standard for Contaminants in Food” (GB2762-2022), but also includes common grain feed such as soybean meal, wheat bran, and corn grits. This makes it the most versatile sample preprocessing technology and product for Benzo(a)pyrene detection in the country.
2. Inclusive for Dairy Products: The current “National Food Safety Standard for the Determination of Benzo(a)pyrene in Food” (GB5009.27-2016) does not include dairy products. This method package is currently the only sample preprocessing technology and product in China applicable for the detection of Benzo(a)pyrene in different fat content dairy products, including light cream, butter, and anhydrous butter.
3. Convenient and Efficient Operation: The method offers simplicity and speed in operation, with high preprocessing efficiency. It allows for simultaneous preprocessing of multiple samples, and the flow rate through the column can be manually increased to control the processing time within the range of 10-25 minutes.
4. Consistent Across Batches: The differences between product batches are minimal, usually eliminating the need for quality control verification experiments on each batch.
5. High and Stable Recovery Rates: The recovery rates are generally within the range of 80%-110%, and the repeatability is characterized by a relative standard deviation (RSD) of less than 5%.
6. Effective Purification: Even for samples with complex matrices, such as sesame oil, chili oil, and light cream, the method demonstrates minimal impurity residue. This significantly reduces contamination of chromatographic columns and instruments.
7. Strong Anti-Interference Capability: The method exhibits robust resistance to interference, even for samples with complex matrices such as sesame oil, chili oil, and light cream. In general, the recovery rates and stability are minimally affected under such conditions.
8. Systematic Integration: The method offers a fully integrated system, providing dedicated Solid-Phase Extraction (SPE) columns and all necessary pre-prepared reagents. This facilitates immediate use upon opening, ensuring a convenient and ready-to-use approach.
9. Diverse Packaging Options: The method is available in three different packaging formats: standard version, sub-packaging version, and combined packaging version. This variety caters to different testing frequency requirements.

Typical Liquid Chromatography Detection Conditions:

1. Liquid Chromatography Columns:
   • Analytical Column: Ultisil® XB-C18 chromatographic column, 4.6mm×250mm, 5μm, Welch Materials (Catalog number: 00201-31043).
   • Guard Column: Ultisil® XB-C18, 4.6mm×10mm, 5μm, Welch Materials (Column core catalog number: 00808-04001; Stainless steel protection column sleeve catalog number: 00808-01101).
2. Mobile Phase:
   • Acetonitrile/Water = 88/12
3. Flow Rate:
   • 1.0 mL/min
4. Detector:
   • Equipped with a fluorescence detector, with an excitation wavelength of 384nm and an emission wavelength of 406nm.
5. Column Temperature:
   • 35℃
6. Injection Volume:
   • 20μL
7. Detection Chromatogram:

Product Information

Product Name	PN	Specifications
Liquid Chromatography Detection of Benzo(a)pyrene Sample Preprocessing Specialized Method Kit (BAP-04 Model)	Bap-P004	HPLC Detection Specialized Standard Version 25 reactions/kit
Liquid Chromatography Detection of Benzo(a)pyrene Sample Preprocessing Specialized Method Kit (BAP-04 Model, Combined Version)	Bap-P004/25A	HPLC Detection Specialized Combined Version 25 reactions/kit
Liquid Chromatography Detection of Benzo(a)pyrene Sample Preprocessing Specialized Method Kit (BAP-04 Model, Combined Version)	Bap-P004/50A	HPLC Detection Specialized Combined Version 50 reactions/kit
Liquid Chromatography Detection of Benzo(a)pyrene Sample Preprocessing Specialized Method Kit (BAP-04 Model, Sub-Packaging Version)	Bap-P004/25D	HPLC Detection Specialized Sub-Packaging Version
Liquid Chromatography Detection of Benzo(a)pyrene Sample Preprocessing Specialized Reagent:	BAP/P03.000	25 reactions/bottle Cream and dairy products