[Moxa nitrogen content determination and its application in moxa floss grade identification]

Area of Science:

• Pharmacognosy
• Analytical Chemistry
• Quality Control in Traditional Chinese Medicine (TCM)

Background:

• Artemisia argyi (mugwort) is a key herb in Traditional Chinese Medicine, commonly used as moxa floss.
• The quality of moxa floss is often determined by its leaf velvet ratio, but objective quantification is needed.
• Nitrogen content is a potential indicator of moxa floss quality and composition.

Purpose of the Study:

• To investigate the relationship between nitrogen content and leaf velvet ratio grades in Artemisia argyi moxa floss.
• To develop and validate mathematical models for predicting moxa floss grades based on nitrogen content.
• To establish a reliable method for objective identification and quality assessment of moxa floss.

Main Methods:

• Collection of Artemisia argyi samples from diverse geographical locations and markets.
• Preparation of moxa floss with varying leaf velvet ratios using a standardized method.
• Determination of nitrogen content using the Kjeldahl method.
• Development and evaluation of six functional models (cubic and exponential selected as best) to correlate nitrogen content with leaf velvet ratio grades.

Main Results:

• An inverse relationship was observed between nitrogen content and leaf velvet ratio grades.
• Cubic and exponential function models demonstrated high accuracy (R² > 0.96) in predicting grades.
• Models achieved over 95% accuracy with laboratory-prepared moxa floss and 85.44% with commercial samples.

Conclusions:

• The developed functional models provide a quantitative and objective method for identifying Artemisia argyi moxa floss grades.
• Nitrogen content analysis, coupled with these models, can serve as a valuable tool for quality control in TCM.
• The models show potential for practical application in the assessment of commercial moxa floss quality.