ARSENIC SPECIATION IN SEAFOOD SAMPLES WITH EMPHASIS ON MINOR CONSTITUENTS - AN INVESTIGATION USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH DETECTION BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY
Eh. Larsen et al., ARSENIC SPECIATION IN SEAFOOD SAMPLES WITH EMPHASIS ON MINOR CONSTITUENTS - AN INVESTIGATION USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH DETECTION BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY, Journal of analytical atomic spectrometry, 8(8), 1993, pp. 1075-1084
Extracts of 11 samples of shrimp, crab, fish, fish liver, shellfish an
d lobster digestive gland (hepatopancreas), including five certified r
eference materials, were investigated for their contents of arsenic co
mpounds (arsenic speciation). The cation-exchange high performance liq
uid chromatography procedure was optimized to separate six cationic ar
senicals present in the samples with internal chromatographic standard
ization by the trimethylselenonium ion, which was detected a m/z 82 (S
e-82), in addition to arsenic at m/z 75, by inductively coupled plasma
mass spectrometry. The content of each species (as arsenic atom) rela
tive to the total arsenic extracted from the samples were: arsenobetai
ne 19-98%, arsenocholine and trimethylarsine oxide 0-0.6% and the trim
ethylarsonium ion 0-2.2%. Additionally, an unknown arsenic species (U1
) was present at 3.1-18% in the shellfish and in the lobster digestive
gland, and another unknown (U2) was present at 0.2-6.4% in all sample
s. The contents of arsenite and arsenate were 0-1.4%, dimethylarsinate
8.2-29% while monomethylarsonate was detected only in oyster at 0.3%
of the total extracted arsenic. Finding tetramethylarsonium ion and ar
senocholine in a variety of samples indicates steps of a biosynthetic
pathway of arsenic leading to arsenobetaine in the marine environment.
The intake of inorganic arsenic via ingestion of the seafood samples
that were analysed did not represent a toxicological problem to humans
. The limits of detection (LOD) were in the range 10-50 ng g-1 (dry ma
ss) with the exception of arsenobetaine for which the LOD was 360 ng g
-1.