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. Author manuscript; available in PMC: 2008 Nov 24.
Published in final edited form as: J AOAC Int. 2008 Jul-Aug;91(4):694–701.

Table 2.

Interlaboratory study results for goldenseal test materials

Results, % (w/w) by Lab No.a
Materialb Analyte 1 2 3 4 5 7 8 9
LPP-01-E01 Hydrastine 2.92 3.01 3.07 3.20 2.90 2.89 3.04 3.24
Berberine 2.66 2.66 3.00 3.10 3.03 2.58 2.92 2.89
LPP-01-E02 Hydrastine 2.56 2.61 2.57 2.70 2.57 2.61 2.63 2.76
Berberine 2.73 2.52 2.63 3.00 2.83 2.58 2.75 2.64
LPP-01-E03 Hydrastine 0.19 0.19 0.16 0.18 0.18 0.17 0.18 0.19
Berberine 0.18 0.18 0.17 0.18 0.18 0.16 0.15 0.17
LPP-01-E04 Hydrastine 2.35 2.56 2.51 2.54 2.39 2.31 2.44 2.51
Berberine 2.99 2.82 3.31 3.40 3.23 2.96 3.20 3.17
LPP-01-E05 Hydrastine 2.87 3.15 2.98 3.20 2.89 2.71 3.04 3.20
Berberine 2.76 2.95 3.22 3.40 3.20 2.79 3.06 3.05
LPP-01-E06 Hydrastine 3.45 3.69 3.71 3.70 3.49 3.23 3.60 3.77
Berberine 2.72 2.50 2.94 3.10 3.03 2.63 2.82 2.92
LPP-01-E07 Hydrastine 2.11 2.48 2.43 2.40 2.24 2.09 2.37 2.45
Berberine 2.74 3.04 3.28 3.20 3.31 2.84 3.10 3.18
LPP-01-E08c Hydrastine 3910 4010 4350 3910 4030 4370 4150 3980
Berberine 5340 6030 5940 5370 5730 4820 5460 5050
a

Laboratory 6 was unable to meet system suitability requirements.

b

LPP-01-E01 = Capsules, goldenseal ground root powder, 550 mg/capsule; LPP-01-E02 = capsules, goldenseal extract, 250 mg/capsule; LPP-01-E03 = capsules, Echinacea purpurea root extract (680 mg) with goldenseal root extract (100 mg); LPP-01-E04 = goldenseal root powder; LPP-01-E05 = goldenseal root, ground to 80 mesh in originating laboratory; LPP-01-E06 = goldenseal root, ground to 80 mesh in originating laboratory; LPP-01-E07 = goldenseal ground root powder (certified organic); LPP-01-EOS = goldenseal ethanol tincture.

c

Results for LPP-01-EOS in μg/mL.