This is remarkable, and leads to me question what numbers this article is reporting. Their cadmium figures are parts-per-billion—ranging 30–45 μg/L. That seems impossibly low for something that's mostly phosphate; i.e., the EU's inorganic fertilizer standard[0] is 60 mg/kg, and they call 20 mg/kg "low-cadmium".
This would appear to be several order of magnitudes lower cadmium than "low-cadmium" fertilizer. That doesn't sound very plausible, does it? Given their common component.
OP's using μg/L. What is a "liter" in the denominator? That'd be an odd unit for measuring a dry powder. Is it liters of the solvent they dissolved the sample in, before running the mass spec? Was it intended to be reported as a a quantitative measurement, at all? (Was there maybe a communication error between the lab technician and the journalist?)
This is remarkable, and leads to me question what numbers this article is reporting. Their cadmium figures are parts-per-billion—ranging 30–45 μg/L. That seems impossibly low for something that's mostly phosphate; i.e., the EU's inorganic fertilizer standard[0] is 60 mg/kg, and they call 20 mg/kg "low-cadmium".
This would appear to be several order of magnitudes lower cadmium than "low-cadmium" fertilizer. That doesn't sound very plausible, does it? Given their common component.
OP's using μg/L. What is a "liter" in the denominator? That'd be an odd unit for measuring a dry powder. Is it liters of the solvent they dissolved the sample in, before running the mass spec? Was it intended to be reported as a a quantitative measurement, at all? (Was there maybe a communication error between the lab technician and the journalist?)
[0] https://www.europarl.europa.eu/news/en/press-room/20181119IP... (Fertilisers/cadmium: Parliament and Council negotiators reach provisional deal")