Chemical Metrology at Nano Scale:Challenges & Solutions

The chemical metrology at nono scale poses many challenges like a. environmental contamination, which increases as the levels go down, b. availability of very sensitive instruments which satisfies the metrological needs and c. well-trained manpower. The sources of contamination that need to be controlled are particulate matter in the environment, containers and reagents used during sample preparation and the analyst performing the operations.

In view of these special requirements for chemical metrology at these levels, an Ultra Trace Analysis laboratory at National Centre for Compositional Characterization of Materials, under Bhabha Atomic Research Centre was set up at Hyderabad in the year 1997, with fully indigenous efforts. It has 900 sq mt clean areas with graded zones of cleanliness consisting of class 100, Class 1000 and Class 10000 rooms. The work benches on which the actual sample processing is carried out are class 10.

The different instruments housed in the clean lab are ICP-QMS, GD-QMS, GFAAS. Certain examples of chemical metrology at nano scale in different applied areas developed at NCCCM are 

1. Analysis of 99.9999 (6N) to 99.99999 (7N) pure materials such as Ga, Ge, Te, In, Sb, Cd, SiO₂, As₂O₃. 2. Many low level contaminants present in the environment like Pt, Pd, Hg, As, Se and its species. 3. Inorganic trace metals in pharmaceutical industry like Pt, Pd mainly used as catalyst.

The laboratory has recently got ISO 17025 accreditation by NABL, hence uncertainty and traceability of measurements are done as per the guideline.