Development and validation of standard and real patient gallstone library using Fourier transform infra-red spectroscopy

Background

Analysis of the constituents of gallstones using various spectroscopic techniques assists in identification of the pathogenesis of gallstones. In the current study, using Fourier Transform Infra-Red (FTIR) Spectroscopy, a Gallstone Standard Library (GSL) and a Gallstone Real Patients’ Library (GRPL) were developed and validated for gallstone composition analysis.

Methods

The study was conducted at the Department of Pathology & Laboratory Medicine, Aga Khan University, Pakistan. Pure standards (cholesterol, calcium carbonate, bilirubin and bile salts) and gallstone specimens were analyzed using FTIR Nicolet iS-5 Spectrometer from Thermo Fisher Scientific, USA. Thermo Scientific™ QCheck™ algorithm, embedded within the OMNIC™ software, was used to identify the unique spectral fingerprint of the patient samples to match with known, standard material. Matching of > 75% was considered acceptable. Validation for accuracy of the library was performed for twenty analyzed gallstones at an international reference lab.

Results

Concerted search analysis was performed against the developed GSL consisting of 71 “pure component” spectrum divided into 5 types to generate the library. For the Gallstone Real Patient Library (GRPL), 117 patient samples were analyzed. Ninety-eight gall stones (83.8%) out of 117 stones matched with the developed GSL. Majority stones were mixed stones (95.92%), with cholesterol being the primary component (91.83%). Results of the developed library were 100% in agreement with the reports received from the external reference lab.

Conclusions

The library developed displayed good consistency and can be used for detection of gallstone composition in Pakistan and replace the traditional labor- and time-intensive chemical method of gallstone analysis.

Standardization of Shodhita Naga with special reference to thermogravimetry and infra-red spectroscopy

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.

Aim:

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.

Material and 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.

Conclusion:

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.