The issue of the content of inorganic elements in traditional Chinese medicines is becoming more and more eye-catching. Excessive amounts will not only cause a decline in the quality of traditional Chinese medicines, but will also cause significant harm to the metabolism and normal physiological functions of the human body. American ginseng is a perennial herbaceous plant belonging to the Araliaceae family and the genus Panax ginseng. It nourishes the lungs, reduces fire, produces fluid, and relieves fatigue. At present, American ginseng is mostly available on the market in the form of medicinal materials, slices or powder for consumers to choose directly. Because the planting, production, and processing of American ginseng are greatly affected by factors such as the geographical environment, especially heavy metal and harmful element pollution in the environment may affect the safety of long-term use. In the recent sampling inspection notice issued by the Shandong Food and Drug Administration, a total of 8 batches of drugs were marked as not meeting the standards, 3 of which were American ginseng drugs.
In order to ensure the quality and safety of American ginseng, it is necessary to investigate the heavy metals and harmful elements contained in it. However, at present, the detection of heavy metals in American ginseng mainly uses methods such as flame atomic absorption, graphite furnace atomic absorption, and hydride generation, which have problems such as high acid consumption, long time consumption, and complicated processes. Therefore, this application center referred to the " Chinese Pharmacopoeia 2020 Edition " and the "Supplementary Test Method for Permanganate Inspection Items in Ginseng and American Ginseng Medicinal Materials (BJY 202109)" to establish the use of microwave digestion and ICP-MS to analyze Mn and Cu in American ginseng. , As, Cd, Hg, Pb and other 6 elements, the method is easy to operate and can complete the test quickly and accurately.
Keywords: ICP-MS, medicine, American ginseng, Chinese Pharmacopoeia 2020, heavy metal pollution
Experimental part
instrument
EXPEC Technology EXPEC 790S super microwave chemical workstation and SUPEC 7000 ICP-MS equipped with standard nickel cone, quartz sampling system and standard TEC refrigeration module (see Figures 1 and 2).
At issue before the U.S. Court of Appeals for the District of Columbia Circuit was the latest take of the Federal Communications Commission on net neutrality, adopted on a party-line vote in 2017. The Republican-penned order not only eliminated the strict net neutrality rules the FCC had adopted when it had a Democratic majority in 2015, but rejected the commission's authority to require broadband providers to do much of anything. The order also declared that state and local governments couldn't regulate broadband providers either.
The commission argued that other agencies would protect against anti-competitive behavior,such as a broadband-providing conglomerate like AT&T favoring its own video-streaming service at the expense of Netflix and Apple TV. Yet the FCC also ended the investigations of broadband providers that imposed data caps on their rivals' streaming services but not their own.
On Tuesday, the appeals court unanimously upheld the 2017 order deregulating broadband providers, citing a Supreme Court ruling from 2005 that upheld a similarly deregulatory move.But Judge Patricia Millett rightly argued in a concurring opinion that "the result is unhinged from the realities of modern broadband service,"and said Congress or the Supreme Court could intervene to "avoid trapping Internet regulation in technological anachronism."
In the meantime, the court threw out the FCC's attempt to block all state rules on net neutrality, while preserving the commission's power to pre-empt individual state laws that undermine its order. That means more battles like the one now going on between the Justice Department and California, which enacted a tough net neutrality law in the wake of the FCC's abdication.
The endless legal battles and back-and-forth at the FCC cry out for Congress to act. It needs to give the commission explicit authority once and for all to bar broadband providers from meddling in the traffic on their network and to create clear rules protecting openness and innovation online.
Table 2 Detection parameters of inductively coupled plasma mass spectrometer
Reagents and standards
Reagents: high-grade pure nitric acid (CNW), high-grade pure hydrogen peroxide (Sinopharm Group);
Pure water: 18.2 MΩ·cm deionized water (25℃);
Standard solution: Cu, As, Cd, Hg, Pb, Au, Mn single element standard solution, 1000 μg/mL, (National Institute of Nonferrous Metals).
Experimental samples and processing
The sample and its status after digestion are shown in Figures 3 and 4 below.
Experimental process and results
1. Calibration curve and detection limit
By digesting the result of 10 blank injections SD*3*dilution factor, the method detection limit (MDL) and calibration curve linearity (measured by the correlation coefficient R^2) of the six elements were calculated.
2. Sample measurement results and quality control
Test the digested samples. Repeat the measurement three times for each sample. Calculate the average of the measured values. Add the standard solution to the sample. The amount of standard solution is about 0.5 times to 2 times the sample result. Conduct the test on the spiked samples. Determination and calculation of spike recovery rate;
3. Test precision
In order to examine the stability of the instrument when measuring samples, samples were continuously injected and analyzed 10 times to test the precision of the system. The RSD values of the measured values of all elements were within 10%.
Conclusion
The above experimental results show that microwave digestion can efficiently process American ginseng samples. Combined with ICP-MS determination, it is easy to operate, has high sensitivity, precision and accuracy, and can meet the pharmacopoeia requirements for six types of manganese, copper, arsenic, cadmium, mercury and lead in American ginseng. It meets the requirements for rapid and accurate determination of heavy metal elements. At the same time, the American ginseng samples tested by this method all meet the limit requirements of the "Chinese Pharmacopoeia 2020 Edition".
Appendix
Equipment and consumables solutions
1. Configuration details of SUPEC 7000 standard sampling system
2. Reagents and standards
