ppm Detection Limits with mg Sized Samples
Heavy metals by USP 231 generally requires
large samples (0.5-1 g), too much for some very expensive drugs produced in
small quantities such as proteins and peptides. Since ICPMS
is the most sensitive technique for trace elements in solution, a 10 mg sample
will give detection limits for most elements in the range of 0.01-1 ug/g (ppm).
More than 60 elements can be determined in the same analysis which is a big
advantage over GFAA where each element is done separately.
We call this analysis an ICPMS
bind metals, and the metal assay is important for QC. Here again, using only
very small samples, ICPMS can accurately assay the metal content. For
injectable drugs, trace aluminum is an important element to monitor. Depending
on the formulation, detection limits of 10 ug/L (ppb) or less can be achieved.
Typical detection limits for ICPMS are 0.01-1 ug/L (ppb) in solution.
Sample preparation usually consists of simply diluting the sample in 1% nitric
acid although we offer a variety of digestion techniques. For