Sample preparation for ICP analysis of biochar typically involves the following steps:
1. Homogenization: The biochar sample is first ground and homogenized to ensure that the sample is representative and that any heterogeneous material is evenly distributed.
2. Acid digestion: The homogenized sample is then digested in acid to dissolve the metals and other elements of interest. A mixture of hydrochloric acid (HCl) and nitric acid (HNO3) is commonly used for this purpose. The exact acid mixture and digestion conditions will depend on the specific elements being analyzed and the analytical method used.
3. Filtration: After digestion, the sample is filtered to remove any remaining solids that could interfere with the analysis.
4. Dilution: The filtered solution is then diluted with deionized water to bring the metal concentration within the working range of the ICP instrument.
5. Analysis: The diluted sample is then analyzed by ICP, which measures the concentrations of various metals and elements.
It's important to note that the sample preparation procedure may need to be optimized based on the specific biochar matrix and the metals of interest. The choice of acid mixture, digestion conditions, and dilution factor may need to be adjusted to ensure accurate and precise analysis.
Reference:
Mohan D, Pittman CU. Activated carbons and low cost adsorbents for remediation of tri- and hexavalent chromium from water. Journal of hazardous materials. 2006 Aug 25;137(2):762-811.
This paper might be helpful: Wathudura et al 2020.
Article Microwave and open vessel digestion methods for biochar
A couple of points to add to Lamia Fatima 's answer:
Best of luck.
To supplement the suggestions of the above two experts: Complete digestion should be necessary, right? Digested samples should be clarified. If sedimentation occurs, and u centrifuge it, indicating incomplete digestion and get unreliable data.
Junhang Dong : It depends if "complete extraction" extracts "all" the metal constituents of interest. A complete digestion won't have any particulates, so won't need filtering (operator induced contamination). If there is Si or Ti (for example) still present in solid form, but it is not of interest to the study, then I would suggest it is not an efficient use of time and resources to attempt to dissolve these elements.
On the other hand, there is always the possibility of an insoluble component of Mn or Zn (for example) that requires that extra effort to solubilise.
Vivian Chimezie Usha , I forgot to mention: use of a reference material with known elemental composition (biochar, charcoal, coke, something along those lines) that you treat the same as your samples will give you an indication of how well your process works.
It depends on the amount of charcoal and elements to be determined
- Badges
- Science method