TABLE 6.

Application of ICP-MS in the determination of heavy metal elements in medicinal materials from the whole plants.

Latin name	Medical system	Therapeutic use	Main pharmacological effects	Origin of medicinal materials a	Test results
Acalypha australis L.	Traditional Chinese medicine	Infantile diarrhea, hematochezia	Anti-inflammatory, antioxidant, and anticancer	Sichuan province of China	The contents of 11 heavy metals of Pb, As, Hg, Cd, Cr, Cu, Ti, Ni, Co, Sb, and Zn in A. australis L. were determined. The linear relationship of 11 heavy metal elements is good (R ≥ 0.9992), and the detection limit of the method is 0.250–5.600 μg/kg, the recovery is 88.1%–107.8%, and RSD ≤ 2.39%. Repeatability test: RSD ≤ 3.43%, stability test: RSD ≤ 2.19%, precision test: RSD ≤ 2.03% (Sun et al., 2019)
Aconitum tanguticum (Maxim.) Stapf	Traditional Chinese medicine	Sores, food poisoning, snakebite	Analgesic, anti-inflammatory, and anti-tumor	—	Ten trace elements of Mn, Fe, Co, As, Ni, Se, Cu, Zn, V, and Cr in A. tanguticum (Maxim.) Stapf were determined. The recovery was 94.08%–103.50% (Limao et al., 2011)
Artemisia rupestris L.	Traditional Chinese medicine	Urticaria, dyspepsia, cold, hepatitis, allergic diseases	Antibacterial, anti-inflammatory, anti-allergic, and antioxidant	—	The contents of 15 trace elements of Li, B, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd, Tl, Pb, and Bi in A. rupestris L. were determined. The recoveries of these 15 elements were 80.06%–111.00%, and the relative standard deviation was less than 5.00% (Zhang and Xie, 2014)
Chloranthus multistachys C. Pei	Traditional Chinese medicine	Fracture, cold, skin itching	Anti-inflammatory, analgesic, and antibacterial	Kaili, Guizhou province, China	The contents of 14 Trace elements such as Cu, Pb, Cr, Ni, be, Mo, Ag, Sn, Sb, Tl, V, Co, As, and Cd in C. multistachys C. Pei were determined. The linear relationship of 14 elements meets the analysis requirements, and the correlation coefficient r > 0.9945. Relative standard deviation of repeatability: RSD < 5.0%. Relative standard deviation of precision: RSD < 4%. Recovery range: 84.0%–120.00% (Sun et al., 2021)
Cymbopogon citratus (DC.) Stapf	Arabic medicine	Gastrospasm	Anti-inflammatory and antihypertensive	Saudi Arabia	The contents of Al, Pb, Cd, and As in C. citratus (DC.) Stapf were determined. The recovery of all measured elements was 86.1%–90.6%. The content of Al element is the highest, and the concentration range of Al is 156–1609 mg/kg. The content of Cd is the lowest, and the concentration of Cd is in the range of 0.01–0.10 mg/kg. The washing process reduces toxic elements in all plants. The average % recoveries were Al (47.32%), As (59.1%), Cd (62.03%), and Pb (32.40%) (Brima, 2017)
Elephantopus scaber L.	Traditional Chinese medicine	Cold, conjunctivitis, pharyngitis, acute tonsillitis, epidemic encephalitis B, pertussis	Anti-inflammatory, analgesic, antibacterial, anti-tumor, antioxidant	Hainan, Guangxi, Guangdong, and Anhui provinces or autonomous regions of China	With Ge, In, and Bi as internal standards, the residues of Pb, Cd, As, Hg, and Cu in E. scaber L. were determined. For each determined element, the correlation coefficient r of the standard curve is 0.9991–0.9999, the average recovery is 91.2%–104.7%, and the RSD value is 3.9%–4.8% (Sun, 2019)
Epimedium sagittatum (Siebold & Zucc.) Maxim.	Traditional Chinese medicine	Impotence, arthralgia	Anti-aging and anti-tumor	—	The contents of Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, as, Se, Rb, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Cs, Ba, La, Ce, Nd, Pr, Th, Sm, Ta, Hg, Pb, and Bi in E. sagittatum (Siebold & Zucc.) Maxim. were determined. Mass concentration range is 1.3 × 10−2–93.5 mg·kg−l, in which the content of Fe is 93.5 mg·kg−l and the content of Mn is 76.6 mg·kg−l, which are the two heavy metal elements with the highest content (Wu et al., 2015a)
Equisetum arvense L.	Arabic medicine	Obstetric pain	Anti-inflammatory, analgesic, and bacteriostatic	Saudi Arabia	The contents of Fe, Mn, Zn, Cu, and Se in E. arvense L. were determined. Fe level is the highest and Se level is the lowest among all plants. The TE series levels of all elements in all plants are as follows: Fe 193.4–1757.9 μg/g, Mn 23.6–143.7 μg/g, Zn 15.4–32.7 μg/g, Se 0.13–0.92 μg/g, and Cu 11.3–21.8 μg/g (Brima, 2018)
Equisetum hyemale L.	Arabic medicine	Labor pain	Analgesic, hypoglycemic, antioxidant, anti-tumor, antibacterial, and antiviral	Saudi Arabia	The contents of Al, Pb, Cd, and As in E. hyemale L. were determined. The recovery of all measured elements was 86.1%–90.6%. The content of Al element is the highest, and the concentration range of Al is 156–1609 mg/kg. The content of Cd is the lowest, and the concentration of Cd is in the range of 0.01–0.10 mg/kg. The washing process reduces toxic elements in all plants. The average % recoveries were Al (47.32%), As (59.1%), Cd (62.03%), and Pb (32.40%) (Brima, 2017)
Gynostemma pentaphyllum (Thunb.) Makino	Traditional Chinese medicine	Cough, chronic tracheitis, infectious hepatitis	Anti-inflammatory, antiviral, anti-tumor, anti-aging, and hypoglycemic	Teng County, Guangxi Zhuang autonomous region of China	The order of 19 inorganic elements in G. pentaphyllum (Thunb.) Makino is Ca > Mg > P > Al > Fe > Ti > Sr > Ba > Mn > B > Zn > Cu > Ni > Pb > Cr > V > Li > CD > Co (Chen et al., 2011a)
Houttuynia cordata Thunb.	Traditional Chinese medicine	Inflammation, viral cold, tumor	Bacteriostasis, anti-inflammatory, anti-tumor, and anti-virus	Guizhou, Hebei, Fujian, Guangdong, Jiangsu, Hubei, Sichuan, Zhejiang, and Guangxi provinces or autonomous regions of China	1) The contents of 27 inorganic elements mg, K, Ca, Fe, Li, Be, B, Ti, V, Mn, Co, Ni, Zn, Ga, Sr, Sn, Sb, Ba, Tl, Bi, Al, Cr, Cu, As, Cd, Hg, and Pb in H. cordata Thunb. were determined. The linear relationship of 27 elements is good, and the correlation coefficient R ≥ 0.9986. RSD of precision and repeatability experiment ≤ 6.0%. The recovery was 95.12%–109.48%, RSD ≤ 6.0%. The contents of Mg, K, Ca, and Fe in H. cordata Thunb. were higher (Chen et al., 2019b)
					2) The contents of Mn, Zn, Cu, Co, Ti, Sn, Sb, Ba, Cr, Ni, As, Pb, Hg, and Cd in H. cordata Thunb. were determined. The linear relationship of each element is good in the range of 0.15–695 g/L. The correlation coefficient of the regression equation of each element is r > 0.9997, the detection limit is 0.002–5.120 g/L, the recovery is 97.6%, 103.8%, and the relative standard deviation is ≤3.15%. The contents of Cu, As, Pb, Hg, and Cd in H. cordata Thunb. were lower than the national standard limit (Li et al., 2018b)
Hypericum japonicum Thunb.	Traditional Chinese medicine	Acute and chronic hepatitis	Antibacterial, antimalarial, antiviral, and anti-tumor	Hebei, Jiangsu, Anhui, Guangxi, Fujian, Hunan, and Jiangxi provinces or autonomous regions of China	The contents of 21 kinds of inorganic elements in Radix Rehmanniae were determined. The linear ranges of mass concentrations of Fe, Mg, Ca, Al, K, Na, Zn, Co, Ni, Ba, Mn, P, Se, Ti, Sr, Cu, As, Cd, Cr, Pb, and Hg were, respectively, 50–250 μg/ml (r = 0.9972), 25–100 μg/ml (r = 0.9989), 25–100 μg/ml (r = 0.9977), 2.5–15 μg/ml (r = 0.9996), 25–150 μg/ml (r = 0.9991), 2.5–15 μg/ml (r = 0.9999), 2.5–10 μg/ml (r = 0.9999), 2.5–10 μg/ml (r = 0.9999), 2.5–10 μg/ml (r = 0.9999), 2.5–10 μg/ml (r = 0.9999), 2.5–10 μg/ml (r = 0.9998), 2.5–10 μg/ml (r = 0.9996), 0.5–2 μg/ml (r = 0.9995), 2.5–10 μg/ml (r = 0.9999), 0.5–2 μg/ml (r = 0.9983), 2.5–10 μg/ml (r = 0.9997), 2.5–10 μg/ml (r = 0.9999), 2.5–10 μg/ml (r = 0.9999), 2.5–10 μg/ml (r = 0.9999), 0.05–0.2 μg/ml (r = 0.9992), and 0.05–0.2 μg/ml (r = 0.9997). RSD of the precision, stability, and repeatability test is less than 5.0%. The recovery was 93.9%–106.9% (RSD was 0.22%–2.94%, n = 6) (Ma et al., 2017)
Mosla chinensis Maxim.	Traditional Chinese medicine	Cold, headache, abdominal pain	Antiviral agents, microorganisms, sedation, antioxidation	Jiangxi province of China	1) The contents of mineral elements in the stems and leaves of M. chinensis and the contents of 25 elements of K, Ca, P, Mg, Al, Mn, Ba, Fe, Zn, Na, Sr, B, Cu, Ti, Pb, Cr, Ga, V, Ni, Cd, Sn, Co, sb, Li, and Be in M. chinensis Maxim. were determined. The contents of major elements such as K, Ca, P, and Mg and trace elements such as Mn, Fe, Zn, and Sr are higher, and the content in leaves is generally higher than that in stems (Yi et al., 2012)
					2) The contents of K, Na, P, Al, Mn, Fe, Ca, Zn, Cu, Ba, Sr, B, Ti, Cr, Ga, V, Ni, Sn, Y, Co, Li, Sb, Be, Tl, Pb, Cd, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu in the stems and leaves of M. chinensis Maxim. from four different habitats in Jiangxi, China, were determined. K. Na, Ca, Mg, Fe, Zn, Mn, and other elements are abundant (Xu et al., 2014)
Mussaenda pubescens Dryand.	Traditional Chinese medicine	Cold, heatstroke, tonsillitis, cough, diarrhea, dysentery, poisonous snakebite	Anti-inflammatory, antibacterial, anticholinergic, and antifertility	Guangxi, Hunan, and Jiangxi provinces or autonomous regions of China	The contents of V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Cd, Sn, Sb, Ba, Hg, and Pb in M. pubescens Dryand from different producing areas in Guangxi, Hunan, and Jiangxi province were determined. The linear coefficient r > 0.9992, the RSD of the repeatability test < 2.5%, the RSD of the precision test is 0.91%–3.7%, and the recovery is 85.6%–109.4% (Chu et al., 2020)
Nepeta coerulescens Maxim.	Tibetan medicine	Oculopathy	Antibacterial	Qinghai province of China	The contents of Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Ag, and Pb in N. coerulescens Maxim. were determined. The contents of Fe, Zn, and Cu in N. coerulescens Maxim. are higher: Fe 763.50 mg/kg, Zn 204.10 mg/kg, and Cu 97.71 mg/kg, respectively, whereas the contents of As, Pb, and Cd are lower, between 0.09 mg/kg and 2.53 mg/kg (Ye et al., 2019)
Odontosoria chinensis (L.) J.Sm.	Traditional Chinese medicine	Cold, fever, enteritis, food poisoning, burns, pesticide poisoning	Antibacterial, antioxidant, anti-inflammatory, anti-tumor, hypoglycemic	Guizhou, Hunan, Sichuan, Chongqing, Fujian, Yunnan, Guangxi, and Jiangxi provinces, municipalities, or autonomous regions of China	The contents of Cu, As, Cd, Hg, and Pb in 14 batches of O. chinensis (L.) J.Sm. from different producing areas such as Yunnan, Guizhou, and Sichuan were determined. Cu 2.63–12.89 mg/kg (RSD53.1%), As 0.29–1.56 mg/kg (RSD59.2%), Cd 0.01–2.55 mg/kg (RSD131.1%), Hg 0.01–0.24 mg/kg (RSD131.1%), Pb 1.09–22.56 mg/kg (RSD129.4%) (Ming et al., 2020)
Piper wallichii (Miq.) Hand.-Mazz.	Miao medicine of China	Dysmenorrhea, impotence, cough	Analgesia	—	The contents of Pb, Cd, As, Hg, and Cu in P. wallichii (Miq.) Hand.-Mazz. were determined. The correlation coefficient of the standard curve of five elements is r > 0.9994, the recovery is 94.6%–107.4%, and RSD < 5% (Chen and Zhang, 2020)
Pogostemon cablin (Blanco) Benth.	Traditional Chinese medicine	Dampness and turbidity, diarrhea, turbid nose, headache	Anti-inflammatory, analgesic, antibacterial, and antiviral microorganisms	Hainan and Guangdong provinces of China	The contents of trace elements in P. cablin (Blanco) Benth. from different producing areas such as Hainan province, Zhanjiang, and Guangdong province were determined. P. cablin (Blanco) Benth. contains B, Na, Mg, AI, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Se, Sr, Mo, Sn, Cs, Ba, Ti, Ga, and Ge (Zhang et al., 2011)
Scleromitrion diffusum (Willd.) R. J. Wang	Traditional Chinese medicine	Various types of inflammation	Anti-inflammatory, anti-tumor, antioxidant, and anti-chemical mutagenesis	Anhui, Yunnan, and Hainan provinces of China	The contents of 14 trace elements Mn, Cr, Sr, Zn, Rb, B, Ni, Cu, V, Sn, As, Mo, Se, and Co in S. diffusum (Willd.) R. J. Wang and its easily mixed product O. corymbosa L. were determined. The linear relationship of 14 elements is good in the range of 0–500 g/L, the correlation coefficient r ≥ 0.9998, the detection limit is 0.0019–0.1644 g/L, and the recovery is 97.5%–120.0%. S. diffusum (Willd.) R. J. Wang contains more Sn elements, and the waterline contains more of the other 13 elements. The contents of Mn, Cr, Sr, Zn, and other elements in the two kinds of medicinal materials are relatively high (Wang and Jin, 2018)
Oldenlandia corymbosa L.	Traditional Chinese medicine	Malaria, cancer, appendicitis	Anti tumor, anti-inflammatory, antimalarial, antioxidant and antibacterial	Anhui, Yunnan and Hainan Provinces of China
Vincetoxicum mukdenense Kitag.	Zhuang medicine of China	Snakebite, infantile chancre, dysentery, toothache	Analgesic, bacteriostatic, and anti-inflammatory	Guangxi Zhuang autonomous region of China	The contents of Pb, Cd, As, Hg, and Cu in V. mukdenense Kitag. were determined. The content range of each element is Pb 0.2301–0.6836 mg/kg, Cd 0.0717–0.1957 mg/kg, As 0.0250–0.0750 mg/kg, Hg 4.2794–7.7946 μg/kg, and Cu 0.9943–1.5444 mg/kg (Chen et al., 2018a)

^aNote: the origin of medicinal materials recorded in the table is collected from the articles.

If the origin of medicinal materials is not recorded in the articles, it is indicated by “—.”