| ObjectiveMarket researches in recent years show that there are roughly 29 kinds of Chinese medicinal materials and decoction pieces around the country producing area which need sulfur fumigation processing, about 65 kinds in storage should be sulfur smoked, and even more Chinese herbal medicine are given sulfur fumigation to achieve colorful and beautiful appearance. Lack of regulation and low cost of sulfur fumigation in the Chinese herbal medicine processing industry leads to the tendency of misuse. Surveys and sample census data of" 11th five-year plan" national major special project "standard platform for Chinese medicine harmful residue detection technology " show that at present there are about 150 kinds of medicinal materials (slices) in market receiving sulfur fumigation in a disordered state, and nearly 20 species of medicinal materials widely adopt sulfur fumigation. After sulfur fumigated, the elements such as potassium, sodium and calcium are resided in the samples in forms of sulfite, focal sulfite and bisulfite, their toxicity and residue are expressed by sulfur dioxide and sodium sulfite according to international practice."Sulfur dioxide residue determination method" in traditional Chinese medicine (TCM) earliest was contained in the appendix in supplement of "Chinese pharmacopoeia" 2005 edition and continued being contained and revised in the first supplement of 2010 edition. The method is distillation-redox titration, which is simple and low cost, but the specificity is not strong and accuracy is poor, and false positive interference can appear sometimes.In this subject, in accordance with statutory methods,10 varieties of TCM has been tested including Achyranthis Bidentatae Radix, Puerariae Thomsonii Radix, Asparagi Radix, Gastrodiae Rhizoma, Trichosanthis Radix, Bletillae Rhizoma, Paeoniae Radix Alba, Atractylodis Macrocephalae Rhizoma, Codonopsis Radix, Dioscoreae Rhizoma. Sulfur dioxide examination was added to these 10 varieties in the second supplement of "Chinese pharmacopoeia" 2010 edition. We has preliminary mastered the nationwide sulfur fumigated condition of Chinese medicine. A testing method of SO2 residue in Chinese herbal medicine with strong specificity, high sensitivity and high degree of automation was created in order to improve the specificity and accuracy of the sulfite determination method. Furthermore, it is necessary to detect the changes of the heavy metals and polycyclic aromatic hydrocarbon before and after sulfur fumigation in Chinese medicinal materials because most of the sulfur in current market comes from the by-product of petroleum cracking process which will produce polycyclic aromatic substances in the oil pyrolysis or incomplete combustion, and sulfur contains heavy metal material such as arsenic and lead, which may contaminate Chinese medicinal materials during fumigation.MethodsAccording to the method in the first supplement of "Chinese pharmacopoeia" 2010 version, we tested 1262 batches of samples with wide coverage and strong representative, which covered 31 provincial administrative regions and the wholesale, retail and medical use unit of Chinese medicine decoction pieces, and statistical analyzed the test results. Furthermore, we improved the method in modern version pharmacopoeia, established the ion chromatography method with higher sensitivity and specificity. We selected a batch of Achyranthis Bidentatae Radix, Codonopsis Radix, Dioscoreae Rhizoma, Atractylodis Macrocephalae Rhizoma and used acid-base titration, iodine titration method and ion chromatography method at the same time for determination and compared the advantages and disadvantages of the three methods, In addition, we prepared sulfur smoked positive samples of Codonopsis Radix, Dioscoreae Rhizoma under the control condition, and detected the changes in the contention of heavy metals, toxic substances and polycyclic aromatic hydrocarbon in traditional Chinese medicine before and after sulfur fumigation by comparatively testing the samples without sulfur fumigated and samples containing sulfur dioxide out of limits.ResultsThe overall qualified rate was 46.9% in 2013 and 86.3% in 2014 by testing the samples according to the legal method in the first "Chinese pharmacopoeia" 2010 supplement edition and the limited requirements in the second supplement. The results showed that the market qualified rates were increased to some extent since the formal implementation of the second "China pharmacopoeia" 2010 supplement edition in December 1,2013, yet the improvement was not ideal.The method of testing SO2 residue in Chinese herbal medicine-ion chromatography was established in reference to the relative standards and literatures at home and abroad, which was exclusive, accurate, sensitive, simple and highly automate, and was used to detect sulfite false positives effectively as a means of assistive technology. This method would be contained in the "Chinese pharmacopoeia" 2015 edition.The three methods-acid-base titration, iodine titration method and ion chromatography method-were compared from the testing way and the aspects of efficiency, sensitivity and specificity; iodine titration and acid-base titration can led to variation caused by the chemical composition with water vapor distillation of different varieties of medicinal materials interfering with the result of the titration, as titration principles are different, therefore it is necessary to investigate different varieties of medicinal materials one by one in methodology, or validate using ion chromatography method.According to ICP-MS method in "lead, cadmium, arsenic, mercury, copper measurement" of "Chinese pharmacopoeia" appendix, the residue of heavy metals and harmful elements before and after the sulfur fumigation were determined in Chinese herbal medicine, with detection index of lead, cadmium, total arsenic, total mercury and copper. The results showed that the contention of residual heavy metals and harmful elements before and after sulfur fumigation have no obvious changes. For the first time, we established the determination methods of 16 kinds of polycyclic aromatic hydrocarbons in Chinese medicinal materials by purifying samples by solid phase extraction method detesting in GCMS method, with corresponding isotopes as internal standard. Methodology investigation showed that this method is sensitive and reliable. The measurement results showed that the polycyclic aromatic hydrocarbon residues have no obvious changes in contention before and after sulfur fumigation.ConclusionIn this study we comprehensively summerized the sulphur fumigated history, the evaluation, usage and regulation of toxicology and pharmacological. We compared the detection methods, optimized the ion chromatography method, which has reached the domestic advanced level and has been loaded into "Chinese Pharmacopoeia". Thousands of representative samples in the country has been tested, preliminary risk assessment has been taken according to the data. This study raises supervisory suggestions, purifies the market order effectively and guides the market development direction.
|
PDF Full Text Request