Multivariate analyses of major and trace elements in 19 species of herbs consumed in Yunnan, China

Figures & data

Table 1. Operating conditions of ICP-AES for herbal samples.

Instrument	ICPE-9000
Spectrometer	Echelle grating
	CCD detector
Power	1.20 kW
Output power	1.2 kW
Argon flow	Cooling gas: 10 L/min
	Auxiliary: 0.6 L/min
	Carrier gas: 0.8 L/min
Nebuliser	Pneumatic (glass concentric)
Spray chamber	Glass cyclonic
Plasma viewing	Axial
Replicates for each analysis run	3
Sample uptake delay	30 s
Elements monitored (wavelength, nm)	barium (230.424), calcium (220.861), cadmium (214.438), chromium (267.716), copper (224.700), iron (234.349), magnesium (383.826), nickel (231.604), strontium (216.596), and zinc (213.856)

Table 2 List of herbal samples and part used and their uses.

Sample code	Pharmaceutical name	Local name	Part use	Medicinal uses
No. 1	Panax ginseng C. A. Mey.	Ren Shen	Root	Strengthen the immunity and tranquillization
No. 2	Panax stipuleanatus Tsai et Feng	Ping Bian San Qi	Rhizome	Eliminate blood stasis and relieve pain
No. 3	Epimedium acuminatum Franch.	Yin Yang Huo	Whole plant	Rheumatic arthritis, enhance libido and sexual performance
No. 4	Codonopsis pilosula (Franch.) Nannf.	Dang Shen	Root	Heart disease and cough
No. 5	Lonicera japonica Thunb	Jin Yin Hua	Flower	Infection diseases, epidemic febrile diseases, sores, and carbuncles
No. 6	Taraxacum mongolicum Hand.-Mazz.	Pu Gong Ying	Whole plant	Clearing heat-toxicity, cold, gastritis, hepatitis, and cholecystitis
No. 7	Lepidium meyenii Walp	Ma Ka	Rhizome	Anti fatigue, enhance memory, improve sleep and sexual performances
No. 8	Gynostemma pentaphyllum (Thunb.) Makino	Jiao Gu Lan	Whole plant	Antitumor and antioxidant activities
No. 9	Perilla frutescens (L.) Britt.	Zi Su	Leaf	Moistening lntestinal, tocolysis, and relieve pain
No. 10	Salvia miltiorrhiza Bunge	Dan Shen	Root	Irregular menstruation, analgesic, sedative, and cirrhosis
No. 11	Lilium brownie var. viridulum	Bai He	Bulb	Dizzy and moisten lung for arresting cough
No. 12	Polygonatum curvistylim Hua	Huang Jing	Tuber	Moisten lung, diabetes, and weakness of the spleen and the stomach
No. 13	Polygonatum odoratum (Mill.) Druce	Yu Zhu	Rhizome	Clear heat and cough
No. 14	Gastrodia elata Bl.	Tian Ma	Tuber	Hypnotic, anti-inflammatory, dizzy, and headache
No. 15	Plantago major L.	Da Che Qian	Whole plant	Cough, cold, bronchitis, enteritis, diarrhea, and hypertension
No. 16	Fagopyrum dibotrys (D. Don) Hara	Jin Qiao Mai	Root tuber	Sore throat, pneumonia, hepatitis, indigestion, and amenorrhea
No. 17	Fallopia multiflora (Thunb.) Harald.	He Shou Wu	Tuber	Acetanilide, hemostatic, hepatitis, insomnia, and soreness and weakness of waist and knees
No. 18	Houttuynia cordata Thunb.	Yu Xing Cao	Leaf	Relieve fever, resolve toxin, reduce swell, drain pus, and promote urination
No. 19	Angelica sinensis (Oliv.) Diels	Dang Gui	Root	Anemia, heart and liver disease, cough, insomnia, and analgesic

Table 3. Assessment of the accuracy and precision by certified reference material, GBW07605 (n = 3).

	Concentration, Mean ± SD (µg/g)
Element	Determined value	Certified value	Recovery (%)
Barium	52 ± 0.0054	58 ± 6	90
Calcium	4081 ± 0.293	4300 ± 400	95
Cadmium	0.05 ± 0.0003	0.057 ± 0.01	88
Chromium	0.8 ± 0.0004	0.8 ± 0.03	100
Copper	16.4 ± 0.0039	17.3 ± 1.8	95
Iron	265 ± 0.0217	264 ± 15	101
Magnesium	1608 ± 0.164	1700 ± 200	95
Nickel	4.2 ± 0.0003	4.6 ± 0.5	92
Strontium	14.8 ± 0.0008	15.2 ± 0.7	97
Zinc	27.6 ± 0.0034	26.3 ± 2	105

Table 4. Statistics of average element concentrations (n = 3) of herbal samples (mean ± SD µg/g).

Sample code	Calcium	Iron	Magnesium	Nickel	Zinc	Barium	Cadmium	Chromium	Copper	Strontium
No. 1	4836 ± 0.18	2273 ± 0.05	2999 ± 0.09	3.05 ± 0.0004	19.0 ± 0.0010	32.5 ± 0.000	0.38 ± 0.0011	5.72 ± 0.0007	7.32 ± 0.003	31.8 ± 0.002
No. 2	5539 ± 0.26	5707 ± 0.22	1998 ± 0.15	14.7 ± 0.0022	36.6 ± 0.0035	148 ± 0.011	0.69 ± 0.0013	5.81 ± 0.0009	36.6 ± 0.004	45.7 ± 0.005
No. 3	7142 ± 1.56	1451 ± 0.30	1564 ± 0.42	2.60 ± 0.0004	82.1 ± 0.0187	17.0 ± 0.004	2.23 ± 0.0006	5.60 ± 0.0015	27.3 ± 0.009	12.2 ± 0.002
No. 4	3359 ± 0.13	1663 ± 0.06	2310 ± 0.32	3.27 ± 0.0006	35.1 ± 0.0013	465 ± 0.044	0.39 ± 0.0006	4.74 ± 0.0007	7.03 ± 0.006	69.8 ± 0.003
No. 5	4689 ± 0.20	775 ± 0.03	2692 ± 0.28	3.11 ± 0.0003	24.1 ± 0.0018	18.2 ± 0.001	0.83 ± 0.0006	3.95 ± 0.0005	9.4 ± 0.004	16.2 ± 0.001
No. 6	22246 ± 0.99	3418 ± 0.11	3634 ± 0.25	6.90 ± 0.0006	44.1 ± 0.0035	63.2 ± 0.002	1.39 ± 0.0013	13.3 ± 0.0005	15.9 ± 0.004	42.1 ± 0.001
No. 7	2539 ± 0.63	183 ± 0.05	823 ± 0.32	0.63 ± 0.0009	18.6 ± 0.0051	9.19 ± 0.003	0.35 ± 0.0007	nd	15.0 ± 0.007	8.25 ± 0.001
No. 8	14693 ± 0.93	2862 ± 0.19	4483 ± 0.33	5.58 ± 0.0011	41.7 ± 0.0047	177 ± 0.010	2.66 ± 0.0010	8.45 ± 0.0005	10.7 ± 0.003	60.7 ± 0.005
No. 9	14474 ± 1.18	1537 ± 0.12	5160 ± 0.13	4.81 ± 0.0005	38.9 ± 0.0014	45.4 ± 0.003	0.49 ± 0.0004	11.0 ± 0.0001	12.1 ± 0.002	53.8 ± 0.003
No. 10	3617 ± 0.15	1078 ± 0.07	6367 ± 0.08	1.24 ± 0.0007	30.6 ± 0.0014	17.0 ± 0.002	0.49 ± 0.0011	3.35 ± 0.0011	13.3 ± 0.004	12.8 ± 0.001
No. 11	3626 ± 0.11	510 ± 0.01	961 ± 0.06	1.73 ± 0.0005	40.3 ± 0.0007	16.6 ± 0.001	0.75 ± 0.0007	1.75 ± 0.0008	17.6 ± 0.002	8.57 ± 0.001
No. 12	3844 ± 0.33	673 ± 0.03	989 ± 0.06	1.23 ± 0.0009	20.3 ± 0.0013	14.0 ± 0.002	1.05 ± 0.0003	1.65 ± 0.0004	11.3 ± 0.007	11.2 ± 0.001
No. 13	6992 ± 0.39	701 ± 0.03	2769 ± 0.16	1.9 ± 0.0007	46.0 ± 0.0002	23.2 ± 0.001	0.15 ± 0.0007	nd	13.3 ± 0.005	12.6 ± 0.002
No. 14	1740 ± 0.22	52.8 ± 0.01	634 ± 0.03	2.00 ± 0.0007	25.8 ± 0.0004	15.4 ± 0.001	0.93 ± 0.0010	0.26 ± 0.0025	6.70 ± 0.000	8.86 ± 0.001
No. 15	21382 ± 0.91	3184 ± 0.09	3336 ± 0.08	4.39 ± 0.0015	36.7 ± 0.0018	218 ± 0.004	0.59 ± 0.0003	8.45 ± 0.0005	11.9 ± 0.005	42.2 ± 0.003
No. 16	6090 ± 0.40	2280 ± 0.07	1924 ± 0.08	6.90 ± 0.0006	17.1 ± 0.0004	36.7 ± 0.001	0.48 ± 0.0010	1.35 ± 0.0006	28.5 ± 0.011	20.2 ± 0.001
No. 17	2857 ± 0.13	460 ± 0.03	1651 ± 0.08	0.97 ± 0.0006	10.7 ± 0.0007	23.1 ± 0.002	0.18 ± 0.0014	0.69 ± 0.0001	4.10 ± 0.003	12.3 ± 0.001
No. 18	10586 ± 0.37	1576 ± 0.05	3862 ± 0.05	6.8 ± 0.0001	37.8 ± 0.0013	53.2 ± 0.002	1.28 ± 0.0003	6.99 ± 0.0007	11.4 ± 0.003	34.7 ± 0.005
No. 19	3744 ± 0.21	428 ± 0.02	3430 ± 0.36	0.57 ± 0.0004	26.0 ± 0.0007	15.7 ± 0.001	0.11 ± 0.0012	1.15 ± 0.0007	6.6 ± 0.001	33.6 ± 0.006
Mean	7579 ± 6214	1622 ± 1416	2715 ± 1551	3.8 ± 3.4	33.2 ± 15.7	74.1 ± 112	0.81 ± 0.68	4.95 ± 3.78	14 ± 8.4	28.3 ± 19.5

nd: not detected.

Table 5. National limits for toxic metals in herbal medicines.

		Cadmium	Chromium	Copper
Canada	Raw herbal materials	0.3 µg/g	2 µg/g
	Finished herbal products	6 µg/day	20 µg/day
China	Herbal materials	1 µg/g
Singapore	Finished herbal products			150 µg/g
Thailand	Herbal material and Finished herbal products	0.3 µg/g

Table 6. Correlation matrix for the element contents in the herbal samples.

	Calcium	Iron	Magnesium	Nickel	Zinc	Barium	Cadmium	Chromium	Copper	Strontium
Calcium	1
Iron	0.533	1
Magnesium	0.472	0.238	1
Nickel	0.378	0.899	0.132	1
Zinc	0.370	0.225	0.134	0.170	1
Barium	0.215	0.410	0.093	0.281	0.117	1
Cadmium	0.382	0.253	0.077	0.226	0.599	0.046	1
Chromium	0.849	0.631	0.562	0.510	0.417	0.308	0.452	1
Copper	0.057	0.584	–0.173	0.664	0.400	–0.061	0.212	0.099	1
Strontium	0.520	0.602	0.460	0.505	0.158	0.770	0.184	0.690	–0.045	1

Figure 1. The principal component loadings of the first two principal components. Principal component 1 (PC1) versus principal component 2 (PC2).

Figure 2. The scores of the first two principal components. Principal component 1 (PC1) versus principal component 2 (PC2)

Figure 3. Dendrogram obtained by the between-groups linkage method and cosine of cluster analysis for the 19 variables and 10 elements (the distances reflect the degree of correlation between different herbs). Number 1-19 is representative of different sample names. See Table 2 for sample names.