NIS - libdoc.who.int - World Health Organization

WHO monographs on medicinal plants commonly used in the Newly Independent States (NIS)
Foreign organic matter
Maximum of 5% of stems from other Equisetum species and hybrids, and
not more than 2% (1) or 1% of other foreign matter. For other parts of
Equisetum arvense L., not more than 1% of other foreign matter and 4%
of other Equisetum species (2). Blackish rhizome fragments and other
foreign matter, not more than 5% (33).
Total ash
Minimum 12% and maximum 27% (1). Not more than 20% (28, 29).
Acid-insoluble ash
Minimum 3%, maximum 15% (1). Not more than 10% (28, 29).
Sulfated ash
No information available.
Water-soluble extractive
Not less than 15% (28, 29).
Alcohol-soluble extractive
No information available.
Loss on drying
Not more than 10% (1).
Pesticide residues
The recommended maximum limit of aldrin and dieldrin is not more than
0.05 mg/kg. For other pesticides, see the European pharmacopoeia (1), the
WHO guidelines on quality control methods for medicinal plants (32)
and the WHO guidelines on pesticide residues (34).
Heavy metals
For maximum limits and analysis of heavy metals, consult the WHO
guidelines on control methods for medicinal plants (32).
Radioactive residues
Where applicable, consult the WHO guidelines on quality control methods
for medicinal plants (32) for the analysis of radioactive isotopes.
Other purity tests
No single-celled protuberances should be present (absence of E. palustre
L.) (28, 29). Not more than 2% foreign matter (29). Not more than
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