Search

Analysis of natural dyes in historical objects is important for both conservation purposes and to determine the origin and culture that produced it. Identification of a particular dye is usually made based on the presence of its main components, while consideration of minor components is important for differentiating between dyes originating from closely related species. Tyrian purple is one of the oldest dyes known to man and derives from different species of marine molluscs. In all of these species, indigotin, indirubin and their brominated analogues are the main colouring compounds. Here, we describe the identification of minor indigoids found in extracts of the pigment obtained from one of the Tyrian purple species, Hexaplex trunculus. Identification of these compounds was made based on isotopic patterns and accurate mass measurements of protonated molecular ions and their high collision energy fragments obtained in LC-MS/MS experiments. The unknown compounds appeared to be analogues of indirubin and its mono- and dibrominated derivatives with one CO group in the indirubin backbone substituted by a CNH group. Identification of these compounds facilitates the detection of dyestuffs from H. trunculus in historical objects and increases our knowledge about the dye biosynthesis and technology of Tyrian purple production. (C) 2012 Elsevier Ltd. All rights reserved.

We have assessed for the first time the current status of tributyltin (TBT) contamination in Hexaplex trunculus along Tunisian coastal waters. Two sampling campaigns have been performed in July 2004 and July 2007 at seven different sites. The snails were analyzed for imposex status, i.e. Imposex incidence, Relative Penis Length Index (RPLI) and Vas Deferens Sequence Index (VDSI), followed by the quantification of butyltins in their tissues. Imposex was detected in six populations from the 2004 samples and in five populations from the 2007 samples. The imposex incidence ranged from 0 (no imposex) to 100%, the RPLI from 0 to 56.7 and the VDSI from 0 to 4.4. TBT was also detected in six populations in 2004 and five populations in 2007. The concentrations ranged from 1.5 to 73.7 ng Sn g(-1) dw in 2004 samples and from 1.2 to 23.9 ng Sn g(-1) dw in 2007 samples. Temporal comparison of the data indicates some evidence of imposex recovery in most affected populations. Improvements in reduced body concentrations of TBT in both sexes were also seen in most stations. These TBT concentrations were only significantly correlated to imposex indices in samples from 2007 (r > 0.8, n = 7, p < 0.05). The present results will serve as a reference for long-term monitoring of butyltin contamination in the Tunisian coast, where TBT restrictions were not yet implemented.

We have assessed for the first time the current status of tributyltin (TBT) contamination in Hexaplex trunculus along Tunisian coastal waters. Two sampling campaigns have been performed in July 2004 and July 2007 at seven different sites. The snails were analyzed for imposex status, i.e. Imposex incidence, Relative Penis Length Index (RPLI) and Vas Deferens Sequence Index (VDSI), followed by the quantification of butyltins in their tissues. Imposex was detected in six populations from the 2004 samples and in five populations from the 2007 samples. The imposex incidence ranged from 0 (no imposex) to 100%, the RPLI from 0 to 56.7 and the VDSI from 0 to 4.4. TBT was also detected in six populations in 2004 and five populations in 2007. The concentrations ranged from 1.5 to 73.7 ng Sn g(-1) dw in 2004 samples and from 1.2 to 23.9 ng Sn g(-1) dw in 2007 samples. Temporal comparison of the data indicates some evidence of imposex recovery in most affected populations. Improvements in reduced body concentrations of TBT in both sexes were also seen in most stations. These TBT concentrations were only significantly correlated to imposex indices in samples from 2007 (r > 0.8, n = 7, p < 0.05). The present results will serve as a reference for long-term monitoring of butyltin contamination in the Tunisian coast, where TBT restrictions were not yet implemented.

We have assessed for the first time the current status of tributyltin (TBT) contamination in Hexaplex trunculus along Tunisian coastal waters. Two sampling campaigns have been performed in July 2004 and July 2007 at seven different sites. The snails were analyzed for imposex status, i.e. Imposex incidence, Relative Penis Length Index (RPLI) and Vas Deferens Sequence Index (VDSI), followed by the quantification of butyltins in their tissues. Imposex was detected in six populations from the 2004 samples and in five populations from the 2007 samples. The imposex incidence ranged from 0 (no imposex) to 100%, the RPLI from 0 to 56.7 and the VDSI from 0 to 4.4. TBT was also detected in six populations in 2004 and five populations in 2007. The concentrations ranged from 1.5 to 73.7 ng Sn g(-1) dw in 2004 samples and from 1.2 to 23.9 ng Sn g(-1) dw in 2007 samples. Temporal comparison of the data indicates some evidence of imposex recovery in most affected populations. Improvements in reduced body concentrations of TBT in both sexes were also seen in most stations. These TBT concentrations were only significantly correlated to imposex indices in samples from 2007 (r > 0.8, n = 7, p < 0.05). The present results will serve as a reference for long-term monitoring of butyltin contamination in the Tunisian coast, where TBT restrictions were not yet implemented.