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Table 2 Limits and experimental results of toxic contaminant tests

From: Quality assurance for Chinese herbal formulae: standardization of IBS-20, a 20-herb preparation

Test Limit (maximum) Herbal formula
Heavy metals:   
Arsenic (As) 2.0 mg/kgb 0.30 mg/kg
Cadmium (Cd) 0.3 mg/kgb 0.13 mg/kg
Mercury (Hg) 0.2 mg/kgb Not detectable
Lead (Pb) 5.0 mg/kgb 0.34 mg/kg
Pesticide residues:   
Aldrin and dieldrin (sum of) 0.05 mg/kgb Not detectable
Chlordane (sum of cis-, trans- and oxychlordane) 0.05 mg/kgb Not detectable
DDT (sum of p,p'-DDT, o,p'-DDT, p,p'-DDE and p,p'-TDE) 1.0 mg/kgb Not detectable
Endrin 0.05 mg/kgb Not detectable
Heptachlor (sum of heptachlor and heptachlor epoxide) 0.05 mg/kgb Not detectable
Hexachlorobenzene 0.1 mg/kgb Not detectable
Hexachlorocyclohexane isomers (α-, β- and δ- hexachlorocyclohexane) 0.3 mg/kgb Not detectable
Lindane (γ-hexachlorocyclohexane) 0.6 mg/kgb Not detectable
Quintozene (sum of quintozene, pentachloroaniline and methyl pentachlorophenyl sulphide) 1.0 mg/kgb Not detectable
Aflatoxin B1 5 μg/kgb Not detectable
Sum of aflatoxins B1, B2, G1 and G2 10 μg/kgb Not detectable
Total plate counts 1000 colony/ga < 10 colony/g
Yeast and mould 100 colony/ga < 10 colony/g
Escherichia coli Absenta Absent
Salmonella species Absent Absent
  1. a Limit required by the Pharmacopoeia of the People's Republic of China (2005 edition)
  2. b Limit required by the Hong Kong Chinese Materia Medica Standards