Concentration of heavy metals in different areas Taizishen Detection
Author: Lishi Hai, Liu Xun Hong, Yan-Ping Zeng,
Dong-hui, ZHANG Yue-chan
【Abstract】 Objective To determine the concentration of heavy metals in different areas heterophylla. Method of
inductively coupled plasma-atomic emission spectrometry and
atomic fluorescence spectrometry of different origin Taizishen lead, chromium and arsenic, mercury, cadmium levels were determined. Results Taizishen of heavy metals were below the
"import and export of medicinal plants and preparation of green industry standard" (2001) provides limits of heavy metals in different production areas Taizishen content of heavy metals in a certain difference. Conclusion The detection
of heavy metals in both for heterophylla heterophylla quality assessment and development of medicinal herbs production of authentic information, but also for the formulation of the standard limits of heavy metals in medicinal herbs provide a reference.
Key words heterophylla; heavy metal
Abstract: ObjectiveTo determine the contents of heavy metals of Radix Pseudostellariae from different habitats. MethodsThe contents of Pb, Cr, As, Hg and Cd were determined by ICP AES and AFS. ResultsThe contents of heavy metals
were different in Radix Pseudostellariae from different habitats . ConclusionIt provides the valuable materials for quality assessment of Radix Pseudostellariae and development production of geo authentic crude drug.
Key words: Radix Pseudostellariae; Heavy Metals
Heterophylla "Chinese Pharmacopoeia" collection contains commonly used traditional Chinese medicine, Jiangsu has always been the main producing areas for heterophylla, the traditional understanding of medicinal products in Jiangsu
Province are considered the best quality real estate Taizishen that there was "genuine medicine," said. The past 20 years, the wild resources dwindling, the original herbal medicine market demand has increased year by year, Anhui, Fujian and
Guizhou and other places have also started large-scale
cultivation heterophylla, with the cultivated area expanded heterophylla, circulation strain increased, medicines internal quality control and the development of genuine medicines production has become a priority. Heavy metal is the
recognized harmful trace elements, heavy metals in traditional Chinese medicine in traditional Chinese medicine issue is to ensure "safe, effective, and controllable," one of the most important issue. Heterophylla medicinal herbs in order to
evaluate the quality of comprehensive development of genuine medicines and to ensure the safety of clinical use of drugs provide the scientific basis of this experiment by inductively coupled plasma-atomic emission spectrometry and microwave
digestion - atomic fluorescence spectrometry of different origin Taizishen lead, chromium and arsenic, mercury, cadmium was detected, are reported below.
An instrument and reagent
Inductively coupled plasma-atomic emission spectroscopy
(Inductively Coupled plasma, referred to as ICP), model MarkIII 1100 vacuum-type 63-channel plasma-atomic emission
spectroscopy (U.S. Jerrel-Ash Company), equipped with
PDPll/23-based computer; atomic fluorescence spectrometer (AFS - 230, Beijing Hai-ray Instruments, Inc.); arsenic, mercury and cadmium hollow cathode lamp (Beijing Hai-ray Instruments
Inc.); microwave digestion instrument (MDS 6, Shanghai Xin
Yi Microwave Chemistry Technology Co., Ltd.); a small temperature-controlled heating plate (Shanghai New Instrument
Microwave Chemistry Technology Co., Ltd.); DF110 type electronic analytical balance.
Lead single element standard solution (1 000 μg / ml,
the national standard solution), chromium single-element
standard solution (100 μg / ml, the national standard
solution), arsenic single-element standard solution (1 000 μg
/ ml, the national standard solution), Cd single-element
standard solution (100 μg / ml, the national standard
solution), mercury single-element standard solution (1 000 μg
/ ml, the national standard solution); experimental reagents addition to thiourea, ascorbic acid, nitric acid, perchloric acid and hydrochloric acid as a priority Pure class, the rest were analytically pure; experiments were deionized distilled
water.
Heterophylla medicinal samples from different areas ID as follows: 1 - Jiangsu Jurong yuanxiangzhen; 2 - Jiangsu Jurong
Ma stems; 3 - King of Town, Jurong, Jiangsu Province, Zhu Xiang Cun Bailong land; 4 - King of the town of Poplar
Village, Jurong, Jiangsu Province ; 5 - Anhui Xuancheng
(050,318); 6 - Anhui Xuancheng (040,516); 7 - Fujian zherong;
8 - Jiangsu Jurong Chen wuxiang He Village; 9 - Guizhou
shibing; 10 - Fujian; 11 - Anhui; 12 - Jiangsu Liyang; 13 -
Jiangsu Jiangning; 14 - Anhui Xuanzhou; 15 - Guizhou. Are
cultivated products, were identified by the author Caryophyllaceae plants Pseudostellaria Pseudostellaria heterophylla (Miq.) Pax ex Pax et Hoffm.'s Roots.
2 Methods and Results
2.1 lead, chromium Inductively Coupled Plasma Emission Spectrometry
2.1.1 Preparation for the test product solution will be
crushed samples, over 100 mesh sieve, dried at 60 ? to
constant weight, samples of about 0.1 g, precision that set, and placing 30 ml poly-PCE beaker, add 5 ml of industrial
super - pure nitric acid, home electric board, cover the surface of III, heating, until clarified, then add 5 ml of industrial ultrapure perchloric acid and continue heating until white smoke basically dissipated, with 7% hydrochloric
acid extraction constant volume to 5 ml, Mesa standby.
2.1.2 working conditions, generator output power 1 100 W, reflected power <5 W, the coil is 4 laps, removable quartz tube torch. Fixed quadrature-type atomizer. Argon purity of
99.99%, pressure 1.6 kg/cm2, the cooling gas flow 17.5 L / min, atomization gas is 0.3 L / min, sample volume increase
1.6 ml / min (using the peristaltic pump), observation height 15 mm, integration time 10 s / times.
2.1.3 Determination of sample solution taken for the test materials, according to the above terms and conditions of work machine for testing. The results in Table 1.
2.2 arsenic, mercury and cadmium Microwave Digestion -
Atomic Fluorescence Determination of
2.2.1 Determination of conditions for equipment condition: negative high voltage photomultiplier 250 V (As, Cd), 300 V (Hg); atomizer temperature of 200 ?; atomizer
height of 8 mm (As, Cd)), 10 mm (Hg); lamp current 60 mA; carrier gas flow rate 400 ml / min; shielding gas flow rate 1 000 ml / min. Measurement conditions: reading time: 10 s; delay time: 1 s; repeat number: 1; measurement: the standard curve method; reading mode: peak area. Reposted elsewhere in the paper for free download http://
2.2.2 Preparation of standard curve of arsenic standard curve: precision-shift to take arsenic standard solution of 1
ml, with 20% hydrochloric acid as the medium progressively diluted to 1 μg / ml of arsenic standard working solution. Arsenic standard working solution were taken in the prior 0,0.5,1.0,2.0,3.0 ml by adding 5 ml 50 mg / ml thiourea -
ascorbic acid mixture (to restore the cover acid agents) in 50 ml flask, with 10% HC1 constant volume to the scale, shake, made of arsenic volume 0,0.01,0.02,0.04,0.06 μg / ml of the
standard series solution at room temperature measured after 30 min. Fluorescence intensity (IF) for the longitudinal
coordinates, depth (C) Preparation of standard curve for the abscissa, arsenic linear equation: IF = 29 080.300 × C 5.675,
r = 0.999 8.
Cadmium Standard Curve: Precision shift taking cadmium standard solution 1 ml, with 5% hydrochloric acid as the
medium progressively diluted to 0.04 μg / ml of cadmium
standard working solution. Cadmium standard working solution were taken in the prior 0,0.5,1.0,2.0,4.0 ml by adding 100 μg
/ ml of cobalt solution (Weigh 0.1000 g high purity metal
cobalt, dissolved in a small amount of [1 +1] hydrochloric acid, diluted with 1% hydrochloric acid and accurate to 1000 ml) 1 ml, 10% thiourea (Thiourea taking 10 g, by adding 50 ml deionized water, dissolved, deionized water, diluted to 100 ml) 10 ml in a 50 ml flask, with 2% HC1 constant volume to the scale, shake, made of cadmium content of 0,0.4,0.8,1.6,3.2 μg
/ ml of the standard series solution at room temperature measured after 30min. Fluorescence intensity (IF) for the vertical axis, the concentration (C) Preparation of standard curve for the abscissa, cadmium linear equation: IF = 758.232 × C-9.284, r = 0.999 6.
Of mercury standard curve: precision-shift to take
mercury standard solution 1 ml, using 0.5 g / L potassium dichromate 5% nitric acid as the medium progressively diluted to 0.01 μg / ml of mercury standard working solution. Mercury standard working solution were taken at 0,1,2,4,8 ml in 100 ml flask with 5% nitric acid to the fixed volume scale, shake, made of mercury volume 0,0.1,0.2,0.4,0.8 μg / L of the
standard series solution at room temperature measured after 30 min. Fluorescence intensity (IF) for the vertical axis, the concentration (C) Preparation of standard curve for the X-
coordinate mercury linear equation: IF = 1 113.798 × C-4.36,
r = 0.999 5.
Table 1 Taizishen of heavy metals in the test results (omitted)
2.2.3 Methodological study precision test: were to take 0.04 μg / ml of arsenic standard solution, 3.2 μg / ml of
cadmium standard solution, 0.2 μg / L standard solution of
mercury were measured five times to repeat sample, arsenic, cadmium , mercury fluorescence intensity values of RSD were 1.1%, 2.8%, 2.9% (n = 5).
Reproducibility test: take the same batch sample (sample 4), measured according to the sample were measured under five times, average arsenic 0.0655 (μg / g), RSD = 1.48%, cadmium
content of average 0.0013 (μg / g), RSD = 1.32%, the average
mercury content of 0.0144 (μg / g), RSD = 2.31%.
Stability test: The samples were collected from four
determination of arsenic, cadmium, mercury test items for the solution method is determined by sample intervals of 30 min measured one times, six times repeated measurements, arsenic, cadmium, mercury, respectively, the fluorescence intensity of
the RSD to 2.3%, 1.8%, 2.7% (n = 6), for the test materials in 3 h to stabilize.
The results of arsenic, the average recovery rate of 95.23%, RSD 1.45%; cadmium average recovery was 102.34%, RSD 2.57%; mercury, the average recovery was 103.55%, RSD of
3.07%.
2.2.4 Sample measurement [1,2] sample preparation: Take the sample powder 0.5 g (over 80 mesh sieve), precision, said fixed, Chi Yung-like cup, with a small amount of deionized water, wet powder, add 10 ml nitric acid, placed heating plate
at 130 ? to make the acid Hui, then add 1 ml perchloric acid (preparation of arsenic, cadmium sample solution), or 4 ml nitric acid and 1 ml perchloric acid (preparation of liquid mercury in the sample), into the microwave digestion
instrument, the By design, the digestion process (Table 2) digestion, after digestion to be removed after the pressure drop, put into a heated board to make the remaining 150 ? Hui
acid, cooling, digestion solution as Arsenic, cadmium, mercury and the sample liquid.
Table 2 digestion process design (a little)
Sample Measurement: To determine the arsenic, the arsenic in the sample fluid transferred to the pre-accession to 5 ml
50 mg / ml thiourea - the mixture of ascorbic acid in 50 ml
flask to 10% HCl constant volume to the scale, determined
after shaking. Determination of cadmium, cadmium sample solution will be transferred to the pre-accession to 100 μg /
ml of cobalt solution 1 ml, 10% thiourea in 10 ml in 50 ml flask, with 2% HC1 constant volume to the scale, determined after shaking. Determination of mercury, will be transferred to the liquid mercury in the sample in 25 ml flask with 0.5 g / L potassium dichromate constant volume of 5% nitric acid to the scale, determined after shaking. The results in Table 1.
3 Summary
Heavy metals, arsenic, mercury, lead, cadmium and others are harmful trace elements, when its accumulation in the body to a certain amount of time can cause the immune system disorder and a variety of function impairment, present, China has developed only a part of traditional Chinese medicine and Chinese medicine formulations lead , arsenic, mercury limit standard of heavy metals in this experiment detected heterophylla, both for the quality evaluation of medicinal
herbs provide a basis for development of the standard limits of heavy metals in medicinal herbs provide a reference.
Based on "import and export of medicinal plants and preparation of green industry standard" (2001) Indicators of
heavy metals limits (mg / kg): Lead (Pb) ? 5.0, cadmium (Cd)
? 0.3, mercury (Hg) ? 0.2, As ( As) ? 2.0. In addition to
chromium (Cr)-free standards, Taizishen of heavy metals were up to standard.
Preliminary test results show that different production
areas Taizishen content of heavy metals have certain differences, Fujian, Guizhou and samples of lead and arsenic content is relatively high, Jiangsu, relatively low levels of arsenic in the sample. With the corresponding results of the analysis of soil origin (another paper), Taizishen of heavy metals in herbal medicine is far lower than the soil samples, indicating Taizishen of arsenic, mercury, lead, cadmium, chromium did not enrichment.
【References】
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Determination of Chinese medicine by microwave digestion of arsenic, mercury study [J]. Modern instruments, 2004,4:12.
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Determination of arsenic-containing traditional Chinese
medicine [J]. Guangzhou Traditional Chinese Medicine, 2005,36 (4): 3. Reposted elsewhere in the paper for free download http://