title: Standardization of Shodhita Naga with special reference to thermogravimetry and infra-red spectroscopy.
abstract: BACKGROUND
  Standardization of Ayurvedic medicine is the need of hour to obtain desired quality of final product. Shodhana literally means purification, is the initial step to make drugs like metals, minerals and poisonous herbs suitable for further procedure. Shodhana of metals/minerals help to expose maximum surface area of drug for chemical reactions and also in impregnation of organic materials and their properties in the drug. Thermo-gravimetric analysis (TGA) facilitates in identifying the presence of organic matter and change in the melting point of metal whereas Fourier transform infra-red spectroscopy (FTIR) assists in identifying the presence of various functional groups.
  
  
  OBJECTIVE
  To standardize the process of Naga Shodhana and to study the change in chemical nature of Shodhita Naga in each media through TGA and FTIR.
  
  
  METHODS
  Samanya and Vishesha Shodhana of Naga was carried out. Time taken for melting of Naga, physico-chemical changes in media used for Shodhana and weight changes after Shodhana were recorded. Samples of Naga were collected after Shodhana in each media for TGA and FTIR analysis.
  
  
  RESULTS
  Average loss occurred during Shodhana was 6.26%. Melting point of Ashuddha Naga was 327.46°C, and it was 328.42°C after Shodhana. Percentage purity of Naga (percentage of lead in Naga) decreased after Shodhana from 99.80% to 99.40%. FTIR analysis of Shodhita Naga in each sample showed stretching vibrations particularly between C-H and C-N bonds that are indicating the presence of various organic compounds.
  
  
  CONCLUSIONS
  According to TGA and FTIR analysis, Shodhana process increases melting point of Naga and initiation of new physico-chemical properties which are indicated by detection of large number of functional groups and organo-metallic nature of Shodhita Naga.
authors.affiliation: Department of Rasashastra and Bhaishajya Kalpana, Ashwin Rural Ayurved College, Ashwi BK, Sangamner, Maharashtra, India.
authors.forename: Dhirajsingh S
authors.initials: DS
authors.lastname: Rajput
authors.affiliation: Department of Rasashastra and Bhaishajya Kalpana, Institute for Post Graduate Teaching and Research in Ayurveda, Gujarat Ayurved University, Jamnagar, Gujarat, India.
authors.forename: Biswajyoti
authors.initials: B
authors.lastname: Patgiri
authors.affiliation: Pharmaceutical Chemistry Laboratory, Institute for Post Graduate Teaching and Research in Ayurveda, Gujarat Ayurved University, Jamnagar, Gujarat, India.
authors.forename: Vinay J
authors.initials: VJ
authors.lastname: Shukla
keywords: Fourier transform infra-red spectroscopy; Naga; Shodhana; standardization; thermo-gravimetric analysis