The total arsenic in seafood samples consumed in the USA varied greatly in the range of 8-22200 ng/g (wet mass). However the most toxic inorganic arsenic species (iAs) was found only in clams and crabs, while non-toxic arsenobetaine (AsB) predominates in most samples.
Human exposure to arsenic results mainly from contaminated drinking water and seafood. Arsenic is one of the metal(oid) of concern who's toxicity depends
heavily on its chemical form. Inorganic arsenic (iAs) is a known
carcinogen that has also been associated with several additional health
problems including heart disease and diabetes. A valuable risk
assessment therefore has to based on the arsenic species being present
rather than on the total arsenic concentration.
Photo: seafood plate (CC BY-SA 3.0,
The new study:
researchers collected fifty-four seafood samples from local
supermarkets and their genospecies was identified by DNA barcoding. The
study focused on the determination of arsenic species in the top ten
most consumed seafoods in the US. Over the last 9 years, shrimp is the
leasing product followed by salmon and canned tuna, altogether
representing more than 50% of total consumption. The other products in
the list are tilapia, pollock, pangasius (swai), cod, crab, catfish, and
clams. The samples were analyzed for total arsenic, water-soluble
arsenic species, and total nonpolar arsenic fraction using a method
developed and validated by the FDA. The speciation analysis is based on
anion and cation HPLC coupled to inductively coupled plasma mass
The concentration of total arsenic in the different seafood samples varied greatly between 8 and 22200 ng/g, with highest levels in crab and lowest in swai and catfish.
Water soluble arsenic fraction
The water soluble arsenic fraction varied from 8-112 %. Arsenic was nearly quantitatively extracted with water from all the tilapia, pollock, and cod samples. Also for most of the shrimp, tuna and crab samples the majority of arsenic was water soluble.
Water soluble arsenic species
Analyte species separated by HPLC were identified by matching their retention times with those of standards. A total of 16 known and 12 unknown arsenic species were detected. Crab and clam samples had the greatest diversity of arsenic species.
Regardless of the very different total arsenic concentration in different seafood samples, inorganic As was either not detectable or present at very low concentration. The highest level found was 145 ng/g in a golden king crab sample.
Arsenobetaine, a nontoxic arsenic species, represented the highest fraction of total arsenic in most of the samples.
Arsenosugars were major components in most of the crabs and clams. None of the finfish and shrimp samples contained any arsenosugar.
Other water-soluble arsenicals
Trimethylarsoniopropionate (TMAP) was found in most matrices with elevated concentrations in crabs (130-800 ng/g). Tetramethylarsonium (TMA) was detected at relatively higher concentrations of 25-90 ng/g in a few samples (shrimp, cod, and crab). Methylarsonic acid (MMA) and trimethylarsine oxide (TMAO) were found almost exclusively in crabs.
Nonpolar arsenic species represented 1-46% of the total arsenic in the respective samples. On average, highest nonpolar fractions were found in catfish (31%) and salmon (26%).
The researchers concluded, that the concentrations of the toxic inorganic arsenic in America’s most consumed seafood products are much lower than the tolerable intake set by the Joint FAO/WHO Expert Committee, even at the highest levels found in this study.
While without doubt, this study represents the most comprehensive survey both in terms of the most relevant seafoods for U.S. consumers and the number of arsenic species evaluated, it also has its limitations. The authors have to admit, that low extraction efficiency and poor chromatographic recovery presented major obstacles to a more complete understanding of arsenic species in certain matrices. Arsenocholine (AsC), dimethylarsinic acid (DMA), dimethylarsinoylacetic acid (DMAA), and dimethylarsinoyl ethanol (DMAE) were present at trace levels throughout
The original studies: Related studies M.M. Wolle
, S.D. Conklin, Speciation analysis of arsenic in seafood and seaweed: Part I − evaluation and optimization of methods
. Anal. Bioanal. Chem., 410 (2018) 5675−5687. DOI: 10.1007/s00216-018-0906-0
, S.D. Conklin, Speciation analysis of arsenic in seafood and seaweed: Part II − single laboratory validation of method.
Anal. Bioanal. Chem., 410/22 (2018) 5689−5702. DOI: 10.1007/s00216-018-0910-4
M.H. Al Amin, C. Xiong, R.A. Glabonjat, K.A. Francesconi
, T. Oguri, J. Yoshinaga, Estimation of daily intake of arsenolipids in Japan based on a market basket survey
. Food Chem. Toxicol., 118 (2018) 245−251. DOI: 10.1016/j.fct.2018.05.019
P.K. Krishnakumar, M.A. Qurban, M. Stiboller, K.E. Nachman, T.V. Joydas, K.P. Manikandan, S.A. Mushir, K.A. Francesconi
, Arsenic and arsenic species in shellfish and finfish from the western Arabian Gulf and consumer health risk assessment
. Sci. Total Environ., 566-567 (2016) 1235−1244. DOI: 10.1016/j.scitotenv.2016.05.180
A.L. Maulvault, P. Anacleto, V. Barbosa, J.J. Sloth
, R.R. Rasmussen, A. Tediosi, M. Fernandez-Tejedor, F.H. van den Heuvel, M. Kotterman, A. Marques, Toxic elements and speciation in seafood samples from different contaminated sites in Europe
. Environ. Res., 143 (2015) 72−81. DOI: 10.1016/j.envres.2015.09.016
A.V. Zmozinski, T. Llorente-Mirandes, J.F. López-Sánchez, M.M. da Silva, Establishment of a method for determination of arsenic species in seafood by LC-ICP-MS
. Food Chem., 173 (2015) 1073−1082. DOI: 10.1016/j.foodchem.2014.10.102
K. Julshamn, B.M. Nilsen, S. Frantzen, S. Valdersnes, A. Maage, K. Nedreaas, J.J. Sloth
, Total and inorganic arsenic in fish samples from Norwegian waters
. Food Addit. Contam. Part B, 5/4 (2012) 229−235. DOI: 10.1080/19393210.2012.698312
A. Ruttens, A.C. Blanpain, L. De Temmerman, N. Waegeneers, Arsenic speciation in food in Belgium. Part 1: Fish, molluscs and crustaceans
. J. Geochem. Explor., 121 (2012) 55−61. DOI: 10.1016/j.gexplo.2012.07.003
M. Fontcuberta, J. Calderon, J.R. Villalbí, F. Centrich, S. Portana, A. Espelt, J. Duran, M. Nebot, Total and inorganic Arsenic in marketed food and associated health risks for the Catalan (Spain) population
. J. Agric. Food Chem., 59/18 (2011) 10013−10022. DOI: 10.1021/jf2013502
A. Leufroy, L. Noël, V. Dufailly, D. Beauchemin
, T. Guérin, Determination of seven arsenic species in seafood by ion exchange chromatography coupled to inductively coupled plasma-mass spectrometry following microwave assisted extraction: method validation and occurrence data
. Talanta, 83/3 (2011) 770−779. DOI: 10.1016/j.talanta.2010.10.050
, E.M. Krupp, Critical review or scientific opinion paper: arsenosugars − a class of benign arsenic species or justification for developing partly speciated arsenic fractionation in foodstuffs?,
Anal. Bioanal. Chem., 399 (2011) 1735−1741. DOI: 10.1007/s00216-010-4303-6
C. Niegel, F.-M. Matysik, Analytical methods for the determination of arsenosugars − a review of recent trends and developments
. Anal. Chim. Acta , 657 (2010) 83−99. DOI: 10.1016/j.aca.2009.10.041
V. Sirot, T. Guérin, J.-L. Volatier, J.-C. Leblanc, Dietary exposure and biomarkers of arsenic in consumers of fish and shellfish from France
. Sci. Total Environ., 407 (2009) 1875−1885. DOI: 10.1016/j.scitotenv.2008.11.050
W. Baeyens, Y. Gao, S. De Galan, M. Bilau, N. Van Larebeke, M. Leermakers, Dietary exposure to total and toxic arsenic in Belgium: Importance of arsenic speciation in North Sea fish
. Mol. Nutr. Food Res., 53 (2009) 558−565. DOI: 10.1002/mnfr.200700533
X. Cao, C. Hao, G. Wang, H. Yang, D. Chen, X. Wang, Sequential extraction combined with HPLC−ICP-MS for As speciation in dry seafood products
. Food Chem. 2009, 113, 720−726. DOI: 10.1016/j.foodchem.2008.08.001
, K. Julshamn, Survey of total and inorganic arsenic content in blue mussels (Mytilus edulis L.) from Norwegian fiords: Revelation of unusual high levels of inorganic arsenic
. J. Agric. Food Chem., 56/4 (2008) 1269−1273. DOI: 10.1021/jf073174+
J. Borak, H.D. Hosgood, Seafood arsenic: Implications for human risk assessment.
Regul. Toxicol. Pharmacol. 47/2 (2007) 204−212. DOI: 10.1016/j.yrtph.2006.09.005
R. Greene, E. Crecelius, Total and inorganic arsenic in Mid-Atlantic marine fish and shellfish and implications for fish advisories
. Integr. Environ. Assess. Manage., 2/4 (2006) 344−354. DOI: 10.1002/ieam.5630020406
S. Hirata, H. Toshimitsu, M. Aihara, Determination of arsenic species in marine samples by HPLC-ICP-MS
. Anal. Sci. 2006, 22, 39−43. DOI: 10.2116/analsci.22.39
, E.H. Larsen
, K. Julshamn, Survey of Inorganic Arsenic in Marine Animals and Marine Certified Reference Materials by Anion Exchange High-Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry,
J. Agric. Food Chem. 2005, 53, 6011−6018. DOI: 10.1021/jf047950e
Hirata, S.; Toshimitsu, H. Determination of arsenic species and arsenosugars in marine samples by HPLC-ICP-MS
. Anal. Bioanal. Chem. 2005, 383, 454−60. DOI: 10.1007/s00216-005-3413-z
U. Nørum, V. W.-M. Lai; S.A. Pergantis
, W.R. Cullen, Arsenic compounds in the haemolymph of the Dungeness crab, Cancer Magister, as determined by using HPLC on-line with inductively coupled plasma mass spectrometry
. J. Environ. Monit., 7/2 (2005) 122−126. DOI: 10.1039/b412311e
, S.A. Pergantis
, Liquid chromatography online with selected reaction monitoring electrospray mass spectrometry for the determination of organoarsenic species in crude extracts of marine reference materials
. Anal. Chem., 77/17 (2005) 5551−63. DOI: 10.1021/ac050445b
E. Argese, C. Bettiol, C. Rigo, S. Bertini, S. Colomban, P.F. Ghetti, Distribution of arsenic compounds in Mytilusgalloprovincialis of the Venice lagoon (Italy)
. Sci. Total Environ., 348 (2005) 267−277. DOI: 10.1016/j.scitotenv.2004.12.071
K. Julshamn, A.-K. Lundebye, K. Heggstad, M.H.G. Berntssen, B. Boe, Norwegian monitoring program on the inorganic and organic contaminants in fish caught in the Barents Sea, Norwegian Sea and North Sea, 1994−2001
. Food Addit. Contam. 21/4 (2004) 365−376. DOI: 10.1080/02652030310001639512
S. Karthikeyan, S. Hirata, C.S.P. Iyer, Determination of arsenic species by microwave-assisted extraction followed by ion-pair chromatography-ICPMS: analysis of reference materials and fish tissues
. Int. J. Environ. Anal. Chem., 84/8 (2004) 573−82. DOI: 10.1080/03067310310001658285
M.W. Fricke, P.A. Creed, A.N. Parks, J.A. Shoemaker, C.A. Schwegel, J.T. Creed, Extraction and detection of a new arsine sulfide containing arsenosugar in molluscs by IC-ICP-MS and IC-ESIMS/MS
. J. Anal. At. Spectrom., 19/11 (2004) 1454−1459. DOI: 10.1039/B408416K
W.-H. Li, C. Wei, C. Zhang, M. Van Hulle, R. Cornelis, X.-R. Zhang, A survey of arsenic species in Chinese seafood
. Food Chem. Toxicol., 41 (2003) 1103−1110. DOI: 10.1016/S0278-6915(03)00063-2
S. Karthikeyan, K. Honda, O. Shikino, S. Hirata, Speciation of arsenic in marine algae and commercial shrimp using ion chromatography with ICP-MS detection
. Atom. Spectrosc., 24/3 (2003) 79−88.
M.M. Storelli, G.O. Marcotrigiano, Total, organic, and inorganic arsenic in some commercial species of crustaceans from the Mediterranean Sea (Italy). J. Food Prot., 64/11 (2001) 1858−1862. DOI: 10.4315/0362-028X-64.11.1858
T. Nakazato, T. Taniguchi, H. Tao, M. Tominaga, A. Miyazaki, Ion exclusion chromatography combined with ICP-MS and hydride generation-ICP-MS for the determination of arsenic species in biological matrices
. J. Anal. At. Spectrom., 15/12 (2000) 1546−1552. DOI: 10.1039/B005981L
S.S.-H. Tao, P.M. Bolger, Dietary arsenic intakes in the United States: FDA Total Diet Study, September 1991−December 1996.
Food Addit. Contam., 16/11 (1999) 465−472. DOI: 10.1080/026520399283759
O. Muñoz, D. Vélez, R. Montoro, Optimization of the solubilization, extraction and determination of inorganic arsenic [As(III) + As(v)] in seafood products by acid digestion, solvent extraction and hydride generation atomic absorption spectrometry
. Analyst, 124 (1999) 601−607. DOI: 10.1039/A809426H
R.A. Schoof, L.J. Yost, J. Eickhoff, E.A. Crecelius, D.W. Cragin, D.M. Meacher, D.B. Menzel, A market basket survey of inorganic arsenic in food
. Food Chem. Toxicol.,37/8 (1999) 839−846. DOI: 10.1016/S0278-6915(99)00073-3