Validation of an analytical procedure for the determination of oxidative hair dyes in cosmetic formulations.
A high range and variety of cosmetic formulations that contain oxidative hair dyes and matrix-forming compounds have been industrially developed over recent years and are now available on the international market. Member states of the European Union are responsible for conducting analyses of cosmetic products as deemed necessary by law and European regulation enforcement. Therefore, inspection authorities as well as the cosmetics trade and industry need validated analytical methods for the identification, characterization, and/or quality control of specific active ingredients or formulations with the aim of implementing the European Union Cosmetic Directives (76/768/ECC, 95/17/EC). In this frame, we validated a candidate reference method that enables the identification and quantification of hair dye-forming compounds. This method consists of a separation by RP-HPLC coupled with a DAD after a liquid-liquid extraction procedure for separating matrix components from the dye-forming compounds. The validation of the method includes common criteria such as the repeatability of the analysis and the establishment of figures of merit, as well as statistical evaluations and quality assurance in order to follow the recommendations of the Eurachem guide for analytical measurements.
Ultrasound-assisted matrix solid-phase dispersive liquid extraction for the determination of intermediates in hair dyes with ion chromatography.
A novel one-step sample preparation technique called ultrasound-assisted matrix solid-phase dispersive liquid extraction was developed. After sample matrices being dispersed, target analytes were extracted into acid solutions and fat and lipin were dissolved in n-hexane while the interfering components were retained by dispersing sorbent. The extraction process could be rapidly accomplished within 9 min with high sample throughput under the synergistic effects of vibration, ultrasound action and heating. The extraction efficiency of approach was demonstrated for the determination of intermediates in commercial hair dyes with ion chromatography. Linearity ranges of 0.2-100 mg L(-1) and detection limits varying from 0.019 to 0.048 mg L(-1) were achieved. The recoveries ranged from 85.7 to 107.0% with the relative standard deviations (RSDs) of 0.31-3.7%. These results showed that the method was simple, time-saving, reliable and suitable for the routine analysis of intermediates in large numbers of hair dyes.
School Principals and Education Law: What do they know, what do they need to know?
Principals now work in complex and challenging environments where uncertainty and change are the hallmarks of their roles and responsibilities. As such, the knowledge and capability demands on principals have expanded, including those related to education law. While these matters attracted some research interest a number of years ago, there has been little recent work in the area of principals and education law. This article reports on an exploratory study into aspects of the legal knowledge held by Tasmanian government school principals, particularly concerning non-sexual physical contact between teachers and students. The research was undertaken using a small-scale, mixed-methods research design, which required principals to respond to various legal scenarios. Three key findings emerged from the study. First, principals used two different levels of working knowledge about education law  one related to legal problems, and the other to legally-related routine activities. Second, on the particular topic of physical contact, some knowledge held by principals was not legally accurate. Third, for major legal issues, participants indicated that they acquired access to information from legal experts. The situation for routine legal matters was less clear, although in-service training and practical experience were identified as potential sources of knowledge. Participants recognised the importance of a sound knowledge of education law, especially for dealing with security and safety issues and preferred to access further information through in-service training. Notably, the findings of the study are broadly consistent with those from earlier Australian and international research, suggesting that much remains to be done in the area of principals’ education law knowledge.