Detection of drugs in hair has become popular in recent years. The significantly long drug detection window (months) in hair has allowed the retrospective investigation and measurement of past consumption of drug. As ...Detection of drugs in hair has become popular in recent years. The significantly long drug detection window (months) in hair has allowed the retrospective investigation and measurement of past consumption of drug. As the majority of drugs are basic, an extraction method was developed based on a methanolic solution for detection of basic/weak basic drugs in hair. It was compared with alkaline digestion (NaOH) followed by LLE. A filtration step with filtration vials was added and their materials were compared. After filtration, extracts were injected directly onto a C18 column coupled to Sciex ABI 2000 MSMS. The mobile phase was 50% methanol, 0.1% formic acid and 2 mM ammonium acetate (isocratic). Both methods were compared by applying them to real samples. Results showed that calibration was linear with r2 of 0.991-0.999 for 20 tested analytes. The matrix effect was assessed to be between 91.4%- 110.2% for 18 analytes. PTFE filter material showed better recoveries over the GMF and PVDF based filters. Stability of analytes during extraction in general was better with methanolic incubation rather than alkaline digestion. With regard to real sample recovery, 6 out of 10 analytes recovered better with alkaline digestion. In conclusion, the methanolic method is capable of extracting most basic drugs in hair samples but only part of the total incorporated drug. Therefore, these results suggest that a combination of both methods (methanolic and alkaline extractions) in hair sample processing for general detection of basic and weak basic drugs may produce better results. However, not all basic drugs are stable under alkaline digestion.展开更多
In this paper, we conduct research on the development track of the computer music and the influences on musical creation. With the advent of the new era of digital music, new music through also started the personal co...In this paper, we conduct research on the development track of the computer music and the influences on musical creation. With the advent of the new era of digital music, new music through also started the personal computer revolution. We only have one computer can onto the road of their own music and creative hobbies. Computer music soRware for all lovers of music, music learners and provides a broad space of infinite music workers： it more into music lovers to indulge in all sorts of wonderful music; It makes the music learners to learn all kinds of music knowledge more efficiently; It makes music workers can follow one＇ s inclinations the use of a variety of voice quality and creative skills, produce more wonderful music works. To further development of the creation procedures, we propose the novel paradigm that will hold special meaning.展开更多
The synthesis focuses on the research methods and the studies on children’s progress in their first language development from early after born to fully mastering of the basic linguistic rules. A comparison between th...The synthesis focuses on the research methods and the studies on children’s progress in their first language development from early after born to fully mastering of the basic linguistic rules. A comparison between the researches of Chinese’s and foreigners’ has also been made. Tremendous achievement has been done on the researches of early language development by both oversea and Chinese researches.展开更多
文摘Detection of drugs in hair has become popular in recent years. The significantly long drug detection window (months) in hair has allowed the retrospective investigation and measurement of past consumption of drug. As the majority of drugs are basic, an extraction method was developed based on a methanolic solution for detection of basic/weak basic drugs in hair. It was compared with alkaline digestion (NaOH) followed by LLE. A filtration step with filtration vials was added and their materials were compared. After filtration, extracts were injected directly onto a C18 column coupled to Sciex ABI 2000 MSMS. The mobile phase was 50% methanol, 0.1% formic acid and 2 mM ammonium acetate (isocratic). Both methods were compared by applying them to real samples. Results showed that calibration was linear with r2 of 0.991-0.999 for 20 tested analytes. The matrix effect was assessed to be between 91.4%- 110.2% for 18 analytes. PTFE filter material showed better recoveries over the GMF and PVDF based filters. Stability of analytes during extraction in general was better with methanolic incubation rather than alkaline digestion. With regard to real sample recovery, 6 out of 10 analytes recovered better with alkaline digestion. In conclusion, the methanolic method is capable of extracting most basic drugs in hair samples but only part of the total incorporated drug. Therefore, these results suggest that a combination of both methods (methanolic and alkaline extractions) in hair sample processing for general detection of basic and weak basic drugs may produce better results. However, not all basic drugs are stable under alkaline digestion.
文摘In this paper, we conduct research on the development track of the computer music and the influences on musical creation. With the advent of the new era of digital music, new music through also started the personal computer revolution. We only have one computer can onto the road of their own music and creative hobbies. Computer music soRware for all lovers of music, music learners and provides a broad space of infinite music workers： it more into music lovers to indulge in all sorts of wonderful music; It makes the music learners to learn all kinds of music knowledge more efficiently; It makes music workers can follow one＇ s inclinations the use of a variety of voice quality and creative skills, produce more wonderful music works. To further development of the creation procedures, we propose the novel paradigm that will hold special meaning.
文摘The synthesis focuses on the research methods and the studies on children’s progress in their first language development from early after born to fully mastering of the basic linguistic rules. A comparison between the researches of Chinese’s and foreigners’ has also been made. Tremendous achievement has been done on the researches of early language development by both oversea and Chinese researches.
