Research On Determination Method Of Heavy Metal Elements In Leather

Leather is essential goods in daily life, and leather shoes, leather coats and hats, gloves, luggage, vehicle interior trimming and so on are leather products. Our country is a large country on leather production, manufacture and consumption, while facing fast and efficient economic development, the leather industry is also facing some problems. Formaldehyde, pentachlorophenol and heavy metal content in leather exceeding standard problem is particularly prominent. The present work employs mass spectrometric technique to study the detection of heavy metals in leather, the main work is as follows:1. Established a fast, simple and efficient method for detecting 7 kinds of heavy metal elements in leather, this is microwave digestion-ICP-MS internal standard method. Microwave digestion method has the following advantages:needing little sample in the digestion process, bringing in less pollution and having less sample loss, having good digestion effect and high efficiency; being able to meet domestic and international requirements for the detection of heavy metal content in leather and leather products; greatly reducing the effect of complex matrix in leather on the detection of content and greatly improving the accuracy of the method with the use of internal standard.2. Established a rapid detection method for 7 kinds of heavy metal elements in leather by using microwave digestion-ICP-MS matrix matching method as the basic method. Semi-quantitative method was used to determine the type of matrix elements in leather samples and to exclude the elements which have low content, and then external standard method was used to measure the exact content of the matrix elements in leather samples, and then adding scheme of the matrix elements in the standard curve was determined. According to the adding scheme of the matrix elements, based on internal standard method, based on the standard curve solutions with matrix were measured in seven kinds of leather, heavy metal element contents. This method couldn't meet domestic and international requirements for leather and leather products for heavy metals testing at present.3. Established a rapid detection method for 7 kinds of heavy metal elements in leather by using microwave digestion-ICP-MS standard addition method as the basic method. The use of microwave digestion method make better digestion of leather samples. Pulling out the homologous sample digestion solutions respectively and adding corresponding concentrations of mixed standard material can be used as a detection method for the heavy metal content in leather.4. Established a detection method for 6 kinds of heavy metal elements in leather by using microwave digestion-IDMS as the basic method. Calculate optimal diluent solution concentration, sampling amount of leather sample and the diluent by using optimal dilution ratio equation based on the basic principles and experimental procedures of isotope dilution mass spectrometry method, add diluent before the pretreatment of sample and design process blank experiment. Once the leather sample and the diluent reach isotope exchange equilibrium after digestion during the experiment, even if there is transfer operation error such as the loss of sample to be detected during the subsequent digestion liquid transfer and dilution it has no effect on the results of the experiment. Isotope dilution mass spectrometry method of six kinds of heavy metal elements were conducted in three times, two element was detected in one time, so greatly saving experimental time. Compared to ICP-MS internal standard method, ICP-MS matrix matching method, ICP-MS standard addition method, isotope dilution mass spectrometry has a higher accuracy and authority.