Determination of total arsenic GERMAN FEDERAL INSTITUTE FOR RISK ASSESSMENT and water-soluble arsenic in the BfR MEAL Study Meals for exposure assessment and analytics in foods Christin                                              1,2 Hackethal ,    Johannes F.                 2 Kopp ,         Tanja                 2 Schwerdtle ,                Oliver         Lindtner 1 1 German Federal Institute for Risk Assessment (BfR), MEAL Study Center, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany 2 University of Potsdam, Institute of Nutritional Science, Arthur-Scheunert-Alle 114-116, 14558 Nuthetal, Germany Background Arsenic is ubiquitous in the environment and occurs in both inorganic and organic form. Due to the toxic                                             The BfR MEAL Study is the first Total Diet Study (TDS) in Germany, which is performed at the Federal potential of inorganic arsenic (iAs), the European Food Safety Authority (EFSA) recommends minimizing                                                Institute for Risk Assessment (BfR) since 2015. TDS denotes an internationally recognized method to the intake and called for more data on arsenic species in food to improve nutrition-based exposure                                                   establish the average concentration in which substances are contained in prepared food. The assessment [1]. Total arsenic, iAs, dimethylarsinic acid (DMA) and arsenobetaine (AsB) were determined in                                            investigated analytes include both substances that are beneficial to health and potentially harmful [2]. foods as part of the BfR MEAL Study. Approach of the BfR MEAL Study Step 1                       Step 2                              Step 3                                       Step 4                                     Step 5                                    Step 6 Selection of foods                       Shopping on national level        Preparation and processing of foods              Pooling and homogenization                            Analysis                      Evaluation and exposure assessment Determination of total arsenic Table 1: Total arsenic (mg/kg) in selected food groups Pooled                             <LOD/LOQ                      modified LB                           UB Food groups                                                                    foods (n) samples (n)                               (%)                Median           P95             Median               P95  The determination of total arsenic was performed by                                    Cereals and cereal-based products                              98                      40              23                0.005           0.039              0.006             0.039 a contract laboratory using inductively coupled                                        Vegetables and vegetable products                              150                     32              31                0.003           0.010              0.003             0.010 plasma mass spectrometry (ICP-MS) after                                                Starchy roots and tubers                                       26                       8              50                0.002           0.006              0.002             0.009 microwave digestion.                                                                   Legumes, nuts, oilseeds and spices                             24                      20              42                0.004           0.040              0.010             0.040  Each samples represents a pool of 20 subsamples. If                                    Fruits and fruit products                                      65                      22              54                0.002           0.004              0.002             0.005 regionality, seasonality or type of production were                                    Meat and meat products                                         101                     35              38                0.002           0.009              0.002             0.009 considered relevant, 15 subsamples per region and /                                    Fish and other seafood                                         39                      30               0                0.855           6.000              0.855             6.000 or season and / or type of production were pooled Milk and dairy products                                        38                      24              71                0.001           0.004              0.002             0.008 into one sample. Foods for infants and small children                           15                      10              33                0.003           0.028*             0.010             0.028*  In total 353 different foods were investigated in 871                                  Composite dishes                                               171                     52              24                0.003           0.025              0.003             0.025 pooled samples. LOD: 0.001 mg As/kg for moist foods, 0.002 mg As/kg for dry foods; LOQ: 0.002 mg As/kg for moist foods, 0.010 mg As/kg for dry foods modified lower bound: values <LOD = 0, values <LOQ = LOD; UB (upper bound): values <LOD = LOD, values < LOQ = LOQ; * maximum Determination of water-soluble arsenic species  The determination of the water-soluble arsenic species iAs, MMA, DMA und AsB based on Raber                                                           Pooled sample                  TFA / H2O2                                        Determination of total arsenic in the et al. [3]. extract using ICP-MS/MS after  Non detected arsenic species are not mentioned in the listed pooled samples.                                                                                                                                                     microwave digestion (extraction efficiency) Table 2: Arsenic content (mg/kg) of selected rice and rice-based (mean ± SD; n=2) [5]                                      [5] Pooled sample              toAs sample                   toAs extract        DMA                iAs              ∑ As-Sp Rice (organic)              0.039 ± 0.0                  0.045 ± 0.002   0.001 ± 0.001     0.033 ± 0.002      0.034 ± 0.002                                                  15 min, 6,000 rpm                   Determination of water-soluble arsenic Rice (conventional)         0.042 ± 0.0                  0.036 ± 0.002   0.008 ± 0.001     0.033 ± 0.001      0.041 ± 0.001                                                                                         species using anion exchange Rice wafers (organic)       0.100 ± 0.0                  0.106 ± 0.001   0.014 ± 0.001     0.088 ± 0.001      0.102 ± 0.001                   Ultrasonic bath                                                             HPLC-ICP-MS/MS Rice wafers (conventional) 0.130 ± 0.0                   0.125 ± 0.002   0.019 ± 0.001     0.106 ± 0.005      0.125 ± 0.005                   15 min, 35 °C Rice pudding (organic)      0.033 ± 4.0                  0.036 ± 0.002   0.014 ± 0.003     0.024 ± 0.006      0.038 ± 0.001                                                                                     Column: Hamilton PRP-X100 (150 x 4 mm; 10 µm) Rice pudding (conventional) 0.025 ± 0.0                  0.021 ± 0.001   0.007 ± 0.001     0.018 ± 0.003      0.025 ± 0.001 Eluent: 3.5 mM Malonic acid / 1% H2O2 Risotto                     0.034 ± 0.0                  0.043 ± 0.006   0.013 ± 0.001     0.024 ± 0.002      0.037 ± 0.002                                                                 [5] (pH 5.6) Transfer aliquot                  Flow rate: 1 mL/min Injection volume: 20 µL Table 3: Arsenic content (mg/kg) of selected fish and fish products (mean ± SD; n=2) Pooled sample                        toAs sample     toAs extract          DMA                 AsB               ∑ As-Sp                                             [5] Verification of arsenobetaine using Dogfish, smoked                      5.70 ± 0.10     4.40 ± 0.29             ND            4.36 ± 0.27               -                         60 min, 95 °C                                                     cation exchange HPLC-ICP-MS/MS Fish fillet, gratinated              0.81 ± 0.01     0.88 ± 0.05         0.07 ± 0.01       0.62 ± 0.04          0.70 ± 0.04 Fish fingers                         0.86 ± 0.05     1.10 ± 0.01         0.09 ± 0.01       0.89 ± 0.02          0.97 ± 0.01                                                                                     Column: Hamilton PRP-X200 Pollack                              1.55 ± 0.07     1.77 ± 0.06         0.15 ± 0.01       1.35 ± 0.04          1.40 ± 0.04                                                                                     (250 x 4 mm; 10 µm) [5]          Eluent: 10 mM Pyridin (pH 2.6) Ocean perch                          2.10 ± 0.00     2.39 ± 0.09         0.24 ± 0.04       1.93 ± 0.01          2.17 ± 0.03                   Ultrasonic bath Tuna fish                            0.85 ± 0.00     1.20 ± 0.04             ND            0.87 ± 0.01               -                        15 min, 35 °C                                                     Flow rate: 1 mL/min 15 min, 15,000 rpm Injection volume: 5 µL Standard 2,5 µg/L 6000 AsB                                                 Rice wafers (organic)               Summary Tuna fish (scaled: intensity/5) 5000                                                                                                                 In 40 % (n = 344) of the pooled samples, the amount of total arsenic was below the limit of DMA                                                                               detection or limit of quantification. Intensity m/z (75→91) [counts] iAs  The highest amounts of total arsenic were determined in fish, fish products and seafood 4000 from 0.01 mg/kg up to 6.2 mg/kg. As expected, arsenobetaine could be identified as predominating water-soluble arsenic species within these samples. Arsenobetaine is known to be virtually non-toxic for humans [6]. 3000  Determined amounts of inorganic arsenic in rice and rice-based samples are below the maximum levels according to Regulation (EU) 2015/1006 (non-parboiled milled rice: 0.20 MMA 2000                                                                                                                  mg/kg; parboiled rice: 0.25 mg/kg; rice wafers: 0.30 mg/kg; rice destined for the production of food for infants and young children: 0.10 mg/kg) [4]. 1000 Sources: [1] EFSA Panel on Contaminants in the Food Chain (CONTAM); Scientific Opinion on Arsenic in Food. EFSA Journal 2009; 0                                                                                                               7(10):1351. [199 pp.]. [2] M. Bürgelt et al., pädiatrische praxis 2019, 91:359-367. 0       1               2              3                  4                 5                   6         [3] G. Raber et al., Food Chem. 2012, 134:524-532. Retention time [min]                                                        [4] Verordnung (EU) 2015/1006 [5] https://smart.servier.com; LES LABORATOIRES SERVIER; https://creativecommons.org/licenses/by/3.0/ Fig. 1: Anion exchange HPLC-ICP-MS/MS separation of arsenic species in extracts of rice wafers and tuna fish.                      [6] T. Kaise et al. Chemosphere, 1985, 14:1327-1332. German Federal Institute for Risk Assessment • Max-Dohrn-Str. 8-10 • 10589 Berlin, GERMANY • Phone +49 30-18412-0 • Fax +49 30-18412-99 0 99 • bfr@bfr.bund.de • www.bfr.bund.de/en