Research Article Analysis of aflatoxins; B1, B2, G1, and G2 in some rice samples of Bangladesh Abida Sultana, Mohammad Shoeb * , Md. Iqbal Rouf Mamun and Nilufar Nahar Department of Chemistry, University of Dhaka, Dhaka, Bangladesh ARTICLE INFO ABSTRACT Article History Received: 22 August 2021 Revised: 18 November2021 Accepted: 23 November 2021 Keywords: Aflatoxins, Aspergillus flavus, Aspergillus parasiticus, Coefficient of variation, Immuno- affinity column. Identification and quantification of aflatoxins; B1, B2, G1, and G2 in twenty different rice samples were done by high-performance liquid chromatography coupled with a fluorescence detector. The rice samples were extracted with aqueous methanol and the extract was purified by immunoaffinity column by following the officially recognized ISO 16050 method. A post column derivatization device (Kobra cell) was used to make Bromo-derivative of the aflatoxins. The method for analysis of aflatoxins in the rice sample was validated in terms of selectivity, linearity, sensitivity, and recovery. Calibration curves were linear with a coefficient of variation r 2 ≥ 0.9998, 09997, 0.9956, and 0.9969 for B1, B2, G1, and G2, respectively. The limit of detection (LOD) was 0.009, 0.006, 0.039, and 0.025 μg kg -1 and the limit of quantification (LOQ) was 0.025, 0.018, 0.116 and 0.075 μg kg -1 for B1, B2, G1, and G2, respectively. Recoveries (n=4) were carried out at two different spiking concentrations (1.39 and 2.77 μg kg -1 for B1, 0.49 and 0.98 μg kg -1 for B2, 1.56 and 3.12 μg kg -1 for G1 and 0.51 and 1.01 μg kg -1 for G2) and were ranged from 56.71±1.60-70.37±5.59%, 57.71±0.58-75.36±6.77%, 65.53±0.73-72.85±5.93% and 65.83±2.92-99.20±3.16% for B1, B2, G1, and G2, respectively. Aflatoxin B1, B2, G1, and G2 in rice samples were found to be present at 70, 60, 40, and 10%, respectively. The total aflatoxins (B1, B2, G1, and G2) in the rice samples were found to be in the range of trace- 3.54 μg kg -1 . The results revealed that 18 out of 20 samples contained the detectable number of aflatoxins. The total aflatoxins content was found to be below the tolerance level (4 μg kg -1 ) according to the European Union (EU). So, the rice samples were safe for consumption, but the major concern is that a large population, especially in rural areas, consumes rice three times a day. If the rice sample contained aflatoxins even, below the present tolerance limit, there is a possibility of bad health implications from the consumption. Introduction Aspergillus flavus and Aspergillus parasiticus are fungi that produce aflatoxins (Reddy et al., 2009). According to the food and agriculture organization of the United Nations (FAO), mycotoxins, including aflatoxins, are responsible for the contamination of at least 25% of the world’s cereal grains (Dowling, 1997). Human health can be affected by aflatoxins, and aflatoxicosis is a disease caused by aflatoxins. To assess the risk of aflatoxins in food, the provisional maximum tolerated daily intake of 1 ng kg -1 body weight/day can be used asthe guidance value (Yazdanpanah et al., 2013). Acute aflatoxicosis can cause sudden death and cancer and immune suppression can be happened by chronic aflatoxicosis (Magnussen and Parsi, 2013). Journal of Bangladesh Academy of Sciences Journal homepage: http://www.bas.org.bd/publications/jbas.html * Corresponding author: <shoeb@du.ac.bd> J. Bangladesh Acad. Sci. 45(2); 187-196: December 2021 DOI: 10.3329/jbas.v45i2.57210