Two Novel Thio-Arsenosugars in Scallops Identified with HPLC - ICPMS and HPLC - ESMS

Abstract

Environmental Context. A new group of arsenic compounds, namely thio-arsenosugars, has recently been discovered in some marine samples, including seafood products. We do not yet understand how these arsenic compounds are produced by living organisms, nor do we know their implications for human health. Their unusual chromatographic properties are the reason that they are difficult to detect by existing methods. We present a new method for finding these thio-arsenosugars, and we also report two new thio-arsenosugars. Abstract. Two new thio-arsenosugars were identified in aqueous and methanol extracts from the gonad and the muscle of the great scallop by using high-performance liquid chromatography–inductively coupled plasma mass spectrometry (HPLC–ICPMS) and HPLC–electrospray ionization mass spectrometry (ESMS). The gonad of the scallops contained thio-arsenosugar–sulfonate [0.067 mg (As) kg−1; dry mass ± 3.7%] and thio-arsenosugar–sulfate [0.267 mg (As) kg−1; dry mass ± 1.2%]. The muscle also contained both thio-arsenosugar–sulfonate [0.030 mg (As) kg−1; dry mass ± 2.6%] and thio-arsenosugar–sulfate [0.200 mg (As) kg−1; dry mass ± 2.6%]. Methanol increased the extraction efficiency threefold for the two thio-arsenosugars as compared to water. Fresh and freeze-dried samples from both parts of the scallop showed no significant difference with respect to the concentration of the two thio-arsenosugars. In order to confirm the presence of the thio-arsenosugars, a new method for their determination with HPLC–ESMS was developed. Under optimized conditions [Hamilton PRP-X100; 150 by 1.0 mm; 20 mM NH4HCO3 with 55% (v/v) methanol at pH 10.3] we succeeded in determining the pseudomolecular ions of thio-arsenosugar–glycerol, thio-arsenosugar–phosphate, thio-arsenosugar–sulfonate, and thio-arsenosugar–sulfate at concentrations less than 5 µg (As) dm−3 in standard solutions and real samples.

Arsenic speciation in bodily fluids of harbor seals (Phoca vitulina) and harbor porpoises (Phocoena phocoena)

“…Thio-Gly was prepared from the oxo-Gly as 302 described elsewhere. [35] Thio-DMAP was prepared by purging the headspace of an HPLC vial containing…”

Oxygen versus sulfur: Structure and reactivity of substituted arsine oxides and arsine sulfides

“…[9] Subsequent work revealed a range of thio-dimethyl arsenicals, and it is now accepted that the oxo analogs and thio analogs coexist in natural samples in ratios depending on the environmental conditions. [10][11][12] The oxo-thio interplay also has human toxicological implications. Thioarsenicals have been detected in urine of people exposed to inorganic arsenic in drinking water, [13] and they are likely to form readily in particular thio-rich cell compartments.…”

Foreword: Research Front—Arsenic Biogeochemistry

“…[10] These studies have led to the discovery of new arsenic compounds, e.g. arseno sulfur sugars in marine animals [6] and corn [9] and metabolites produced in urine on ingestion of seaweed, such as dimethylated arsenic species, [12] that are potentially carcinogenic.…”

“…With the advent of modern analytical instrumentation, such as high pressure liquid chromatography coupled to an inductively coupled mass spectrometer or a mass spectrometer [4] and X-ray spectroscopy, arsenic is being analysed in more and diverse samples including marine organisms such as polychaetes [5] and scallops, [6] terrestrial organisms such as mushrooms and snails, [7,8] food crops [9] and animal and human urine. [10] These studies have led to the discovery of new arsenic compounds, e.g.…”