Wool is the main by-product of sheep, although production has decreased largely during the last decades. In addition, some types of wool with coarse fiber diameter have little value since they are not adequate to be used in the textile sector. This represents a problem for the sheep farmers and, when not transformed, wool needs to be treated as a special waste. However, wool represents a biodegradable renewable resource and due to its complex chemical composition and physical structure and properties, it can find various value-added applications beyond the textile industry. The technological characteristics make wools particularly suitable for different applications such as thermo-acoustic insulation, agricultural amendment, biomedical polymer production, etc. To reduce the risk of adverse effects related to the use of poor quality raw wool in new applications, it is important to assess the quality of this material with regard to both important and common contaminants and residues. The aim of this research was to investigate the degree of contamination of Sarda sheep wool to understand if wool fiber can be a contamination source for both the environment and human health. Chemical analyses were carried out through liquid chromatography-mass spectrometry (LC-MS) and inductively coupled plasma mass spectrometry (ICP -MS). Both analytical techniques were targeted for a wide range of micropollutants including pesticides, veterinary drugs and heavy metals. The raw wools were sampled from three Sardinia's regions during the period May - June 2015. The extraction of veterinary drugs and organophosphate pesticides was achieved using Microwave assisted extraction (MAE), an eco-friendly technique. Taking into account the complexity of the wool matrix, a solid phase extraction (SPE) was introduced as a cleanup step to remove interference. Chromatographic separation was performed by liquid chromatography coupled to Orbitrap Mass Spectrometry. The ionizations were obtained in Electrospray (ESI) operating in positive ion mode. The acquisitions were carried out in Full scan/Data Dependent-MS2 (DDS) with resolving power of 70000 FWHM for the parent ions and 17500 for the fragment ions. ICP-MS approach was used for the simultaneous evaluation of 22 heavy metals. The analysis were performed by means of an Agilent 7500 EC inductively coupled plasma mass spectrometer including an octopole reaction system after digestion of the matrix in the mineralizer microwave. The sample was mineralized by placing 0.2 g of washed and dried wool directly into each microwave vessel. Five ml of HNO3 at 70% was then added, heated to 100°C over 5 min, held at 100 °C for 5 min, left to cool and samples transferred to 50 ml ultrapure water. The results will hopefully represent a contribution to support the use of wool, as a natural resource with low environmental impact, for high value-added products.
Mass Spectrometry Approaches to Evaluate Potentially Hazardous Contaminants and Residues in Raw Wool
Sara Bortolu;Emanuela Azara;Pierpaolo Duce
2016
Abstract
Wool is the main by-product of sheep, although production has decreased largely during the last decades. In addition, some types of wool with coarse fiber diameter have little value since they are not adequate to be used in the textile sector. This represents a problem for the sheep farmers and, when not transformed, wool needs to be treated as a special waste. However, wool represents a biodegradable renewable resource and due to its complex chemical composition and physical structure and properties, it can find various value-added applications beyond the textile industry. The technological characteristics make wools particularly suitable for different applications such as thermo-acoustic insulation, agricultural amendment, biomedical polymer production, etc. To reduce the risk of adverse effects related to the use of poor quality raw wool in new applications, it is important to assess the quality of this material with regard to both important and common contaminants and residues. The aim of this research was to investigate the degree of contamination of Sarda sheep wool to understand if wool fiber can be a contamination source for both the environment and human health. Chemical analyses were carried out through liquid chromatography-mass spectrometry (LC-MS) and inductively coupled plasma mass spectrometry (ICP -MS). Both analytical techniques were targeted for a wide range of micropollutants including pesticides, veterinary drugs and heavy metals. The raw wools were sampled from three Sardinia's regions during the period May - June 2015. The extraction of veterinary drugs and organophosphate pesticides was achieved using Microwave assisted extraction (MAE), an eco-friendly technique. Taking into account the complexity of the wool matrix, a solid phase extraction (SPE) was introduced as a cleanup step to remove interference. Chromatographic separation was performed by liquid chromatography coupled to Orbitrap Mass Spectrometry. The ionizations were obtained in Electrospray (ESI) operating in positive ion mode. The acquisitions were carried out in Full scan/Data Dependent-MS2 (DDS) with resolving power of 70000 FWHM for the parent ions and 17500 for the fragment ions. ICP-MS approach was used for the simultaneous evaluation of 22 heavy metals. The analysis were performed by means of an Agilent 7500 EC inductively coupled plasma mass spectrometer including an octopole reaction system after digestion of the matrix in the mineralizer microwave. The sample was mineralized by placing 0.2 g of washed and dried wool directly into each microwave vessel. Five ml of HNO3 at 70% was then added, heated to 100°C over 5 min, held at 100 °C for 5 min, left to cool and samples transferred to 50 ml ultrapure water. The results will hopefully represent a contribution to support the use of wool, as a natural resource with low environmental impact, for high value-added products.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
