[High-throughput screening of ochratoxin A in Chinese herbal medicines using enzyme-linked immunoassay].

An indirect competitive enzyme-linked immunosorbent assay( ic-ELISA) was developed for the rapid detection of ochratoxin A( OTA) in nutmeg( Myristicae Semen),ginger( Zingiberis Rhizoma) and turmeric( Curcumae Longae Rhizoma). The matrix matching standard curve was used instead of the standard curve of sample diluent,and the sample extract and sample diluent were optimized. The sensitivity( IC_(50)) of this method for OTA in nutmeg,ginger and turmeric were determined as 0. 146,0. 157 and 0. 153 ng·m L~(-1),respectively and the limits of detection( LODs) were 0. 040,0. 032 and 0. 031 ng·m L~(-1),respectively. The recovery of samples ranged from 75. 99% to 122. 3%,with RSD<10%. Two positive samples for nutmeg and one positive sample for turmeric occurred in 50 samples,and the highest OTA contamination value was 1 167. 8 µg·kg~(-1). The results were further confirmed by LC-MS/MS. It shows that the developed ic-ELISA method is simple,rapid and sensitive,and can be applied for rapid and high-throughput screening of OTA in nutmeg,ginger and turmeric,as well as some other CHMs.

[Analysis and health risk assessment of aflatoxin B_1 residue in Ziziphi Spinosae Semen].

This study aimed to analyze the residues of aflatoxin B_1( AFB_1) in Ziziphi Spinosae Semen from different producing areas and to assess the health risk of aflatoxin B_1 residue based on the obtained data. A total of 72 samples of Ziziphi Spinosae Semen from different areas were detected by IAC-HPLC-FLD. Based on the data of AFB_1 pollution,a probabilistic assessment model with Monte Carlo simulation was developed. Then,the risk assessment of AFB_1 exposure by Ziziphi Spinosae Semen intake was carried out by MOE( margin of exposure). The results showed that 32 out of 72 of samples( 44. 4%) were found to be contaminated with AFB_1,and the average and maximum concentration of AFB_1 in samples was 5. 42 µg·kg~(-1) and 55. 09 µg·kg~(-1),respectively. After health risk assessment,the average and 97. 5%( 90% confidence interval) exposure level of daily exposure of AFB_1 by Ziziphi Spinosae Semen intake were 0. 008 6( 0. 008 1-0. 009 2) and 0. 057 3( 0. 053 2-0. 061 4) µg·kg~(-1)·d~(-1),respectively. The results showed common use of Ziziphi Spinosae Semen had low level of risk associated with AFB_1. However,the high consumption of Ziziphi Spinosae Semen showed a higher risk than common intake,requiring attention. This study laid a foundation for clinical safe prescription of Ziziphi Spinosae Semen.

[QuEchERS pretreatment coupled to gas chromatography and tandem mass spectrometry to fast determination of 34 pesticide residues in Glycyrrhizae Radix et Rhizoma].

This study proposed a quantitative method for 34 pesticides including organochlorine,organophosphorus and pyrethroids in Glycyrrhizae Radix et Rhizoma herbs and medicinal slices,and analyzed the pesticide residues of collected Glycyrrhizae Radix et Rhizoma samples from different regions. With acetonitrile extraction and optimized Qu Ech ERS purification,the 32 batches of Glycyrrhizae Radix et Rhizoma herbs and medicinal slices were analyzed by matrix matching standard curve quantitative analysis under GC-MS/MS multi-response monitoring( MRM) mode. This study investigated the pretreatment of Glycyrrhizae Radix et Rhizoma samples based on the Qu Ech ERS method of Chinese Pharmacopoeia( 2015 edition,4),and the result showed that the recoveries of some pesticide was low and pigment has a strong interference in analysis,which result in worse purification effect. Therefore,this paper further optimized the Qu Ech ERS method and corrected the matrix matching standard curve method,and compensated the qualitative and quantitative effects of matrix effects on the detected target compounds in Glycyrrhizae Radix et Rhizoma. The results showed that 34 kinds of pesticide had good linear( R~2 of 0. 996 4 or higher) within a covering 0. 01-0. 2 mg·kg~(-1) concentration range. The limits of quantitation are less than 0. 01 mg·kg~(-1). This method was further applied to the simultaneous determination of 34 pesticide residues of typical organochlorine,organophosphorus and pyrethroids in 32 batches of Glycyrrhizae Radix et Rhizoma herbs and medicinal slices. Six batches containing beta-endosulfan,thiosulphate,o,p'-DDD and thrta-cypermethrin were detected,but none of them exceeded the limit of pesticide residues stipulated in the Chinese Pharmacopoeia and the EU Pharmacopoeia. This study indicates that the established method is rapid,convenient,accurate,and sensitive,which provides a rapid and efficient method for the simultaneous determination of typical organochlorine,organophosphorus and pyrethroids in Glycyrrhizae Radix et Rhizoma.

[Contamination distribution and control measures of aflatoxins in Chinese herbal pieces].

As an important part of traditional medicine in China, traditional Chinese medicine(TCM) plays a significant role because of its unique medical efficiency, less adverse reactions and extensive resources. However, in recent years, the aflatoxins in medicinal herbs have been detected excessive both at home and abroad, seriously affecting the reputation and credibility of traditional Chinese medicine. In this paper, the current status of aflatoxins contamination in medicinal herbs was analyzed, and the internal and external factors of aflatoxins contamination in traditional Chinese medicine were also summarized. In view of the high toxicity of aflatoxins, it is proposed to strengthen the mildew prevention and control from the early planting to storage stage, and the reasonable detoxification mode should also be considered. This review aims to provide a reference in guaranteeing the clinical safe administration of medicinal herbs and reducing the risk of being poisoned by aflatoxins.

[Identification and quality evaluation of Tripterygium wilfordii].

With the extensive clinical application of Tripterygium wilfordii, there are many counterfeit products on the market. Traditional technology can not effectively identify the authenticity of the traditional Chinese medicine. Therefore, a strategy of accurate identification and quality evaluation of Tripterygium based on DNA barcode and chemical fingerprint spectrum was established. Based on DNA barcode technology, HMMer annotation method of hidden Markov model and K2P model were used to analyze genetic distance.BLAST1, nearest distance and phylogenetic tree (NJ-tree) methods were used to assess the identification efficiency of the ITS2 barcode. The fingerprint of 27 T. wilfordii was established by UPLC-PDA method, and the similarity of the fingerprint of different sources was evaluated. The main components of T. wilfordii were determined by LC-MS/MS. The results revealed that the intraspecific genetic distances of T. wilfordii were lower than the interspecific genetic distances between T. wilfordii and its adulterants. The results of similarity search showed that ITS2 sequence was used to identify T. wilfordii and its adulterants. The clustering of T. wilfordii and its adulterants was clear in the tree of NJ cluster, and 12 of 27 samples were identified as true T. wilfordii.The chemical fingerprint spectrum research indicates that the feature one region can distinguish the false product of tripterygium glycosides more intuitively. The cluster analysis of HCA-thermal map showed that the contents of six active components of T. wilfordii from different habitats were significantly different, which could be used to evaluate the quality of T. wilfordii. This paper is of guiding significance for the accurate identification and quality evaluation of Tripterygium medicinal plants.

[Advances on nanoparticles-tagged visual test strips for the rapid detection of pesticides].

The residue of the pesticides affects seriously the quality and safety of traditional Chinese medicine. Pesticide residue has caused ever-growing attention of people at home and abroad. Rapid detection techniques used for rapid screening of pesticide residues have expanded in a fast progress. As one of the fast development methods of rapid detection, visualization test strip based on nanoparticle has received much concern in recent years. This article focused on the classification of detection test strips and key factors on the fabrication of nanoparticle-based visualization test strips used in small molecule pesticides. Moreover, a wide application of nanoparticles-tagged test strips on pesticide residue was reviewed including single residue detection, multi residue detection, as well as quantitative analysis. Finally, the future application of visual test strip for detecting of pesticide residues in traditional Chinese medicine was forecasted, intending to provide the reference for rapid detection techniques on pesticide residues screening in herbal medicine industry.

[Quality control in Menthae Haplocalycis Herba and its decoction slices].

Menthae Haplocalycis Herba has been widely applied in such fields as food, cosmetics, daily necessities, medicine and health, due to its unique efficacy. However, as the safety of traditional Chinese medicines has been of increasing concern, the quality issue of Menthae Haplocalycis Herba and its decoction slices has become a key obstructive factor for exports. This article focused on the control over Menthae Haplocalycis Herba's adulterants, exogenous hazardous residues and internal properties (chemical compositions, spectrum effect relationship). Moreover, current studies on the quality of Menthae Haplocalycis Herba and its decoction slices, as well as the existing problems in recent years were systematically summarized in the expectation of improving the means of quality control of Menthae Haplocalycis Herba and its decoction slices, enhancing its quality standards, and ensuring the use safety and effectiveness.

[Contamination level of aflatoxin B1 in lotus seeds rapid screening by indirect competitive ELISA method].

A simple and cost-effective indirect competitive enzyme-linked immune sorbent assay (ic-ELISA) was developed to rapidly screen the content of aflatoxin B1 (AFB1) in lotus seeds, and the results were confirmed by ultra-fast liquid chromatography-tandem mass spectrometry( UFLC-MS/MS). Matrix-matched calibration expressed a good linearity ranging from 0. 171 to 7. 25 µg · L(-1) for AFB, with R2 > 0.978. The medium inhibitory concentration( IC50 ) for AFB1 was 1.29 µg · L(-1), the recovery for AFB1 was 74.73% to 126.9% with RSD < 5%, and the limit of detection (IC10) was 0.128 µg · L(-1). The developed ic-ELSIA method was applied to rapid analysis of AFB, in 20 lotus seeds samples and the results indicated that the contents of AFB, in samples 1-15 were in the range of 1. 19- 115. 3 µg · kg(-1) and in 40% of the samples exceeded the legal limit(5 µg · kg(-1)), while the contamination rate of AFB, in samples 16-20 was 40%. Pearson correlation coefficient(r) reached 0.997 for AFB1 content in the samples detected by ic-ELSIA and UFLC-MS/MS methods. The results proved that the developed ic-ELISA method is simple, sensitive and reliable, and can be used for rapid and high-throughput screening of AFB1 in lotus seeds

[Status of pesticide registration and residue analysis for traditional Chinese medicine in China].

The present paper outlined pesticide registration status for traditional Chinese medicines (TCMs) and summarized the characteristics of pesticide contamination in different regions of some widely used TCMs by retrieving last 10 years' literatures. At present, the problems of pesticide residues for TCM include less pesticide registrations, widespread high-residue organochlorine pesticides contamination, pesticide abuse, irregular GAP bases and imperfect pesticide limit standards, etc. According to the current situation, we should adopt some control measures to strengthen the quality control of TCMs so as to ensure the safety of TCMs and related products.

Relationship between carbon stock and the structure of coniferous and broad-leaved mixed forest in Tianmu Mountains, China.

Taking the coniferous and broad-leaved mixed forest of Tianmu Mountain National Nature Reserve in Zhejiang Province as research object, we divided the tree species into three pairs, including evergreen and deci-duous species, broad-leaved and coniferous species, dominant and non-dominant species, to compare the difference of the individual tree carbon stock of each pair and analyze the diameter distribution pattern and tree height distribution pattern of carbon stocks. The relationship between spatial structure and individual tree carbon stock was analyzed by using spatial structure indicators including V_Hegyi competition index, complete mingling and aggregation index, to reveal the relationship between the structure of coniferous and broad-leaved forests and carbon stocks, and provide a theoretical basis for management of forest carbon sequestration. The results showed that the average individual carbon stock for evergreen and deciduous species, broad-leaved and coniferous species, dominant and non-dominant species were 57.7 and 87.4 kg, 54.6 and 74.7 kg, 67.4 and 48.1 kg, respectively. The individual tree carbon stock of evergreen species was significantly lower than that of deciduous species, the individual tree carbon stock of broad-leaved species was significantly lower than that of coniferous species, and the individual tree carbon stock of dominant tree species was significantly higher than that of non-dominant tree species. The diameter distribution and height distribution of carbon stock of each species group obeyed normal distribution. The V_Hegyi competition index was significantly negatively correlated with individual tree carbon stock, and it was consistent with the power function distribution. Both complete mingling and aggregation index were linearly and positively correlated with individual tree carbon stock. The direction of influence of different spatial structures on the individual tree carbon stock was consistent. The structure of coniferous and broad-leaved mixed forest had a significant impact on individual tree carbon stock. In the management of forest carbon sequestration and sink enhancement, it is necessary to regulate the unreasonable forest structure and promote its succession to the climax community in order to improve forest carbon stock.

[Gravitational model-based competitive analysis of trees]. / 基于引力模型的林木竞争分析.

Whether the gravitational model can be used to analyze tree competition in forest community is a valuable question. A tree relative vitality circle based on the gravitational model can illustrate the magnitude of competitive tree vitality. A gravitational competition index based on the relative vitality circle of competitive trees can accurately depict the relationship between growth and competition. This study was conducted in the coniferous and broadleaf mixed forest of Tianmu Mountain National Nature Reserve in Zhejiang Province. We carried out correlation analyses between the V_Hegyi competition index and diameter at breast height (DBH), between the gravitational competition index and DBH, and between the two competition indices and the basal area increment. We further analyzed the correlation between the growth rate of DBH and the ratio of the two-phase gravitational competition index, that is, the ratio of the 2021 gravitational competition index to that of 2006. In addition, the correlation analysis was applied between the relative vitality circle diameter and DBH. We also compared the magnitudes of the competition indices between the living standing trees and the dead trees. The results showed that both competition indices were negatively correlated with DBH, and followed a power function relationship. The basal area increment was negatively correlated with each of the two competition indices. However, the gravitational competition index was better than V_Hegyi competition index for indicating the relationship between tree growth and tree competition. Compared with the ratio of the V_Hegyi competition indices, the ratio of the two-phase gravitational competition indices could better demonstrate the relationship between tree growth and tree competition. In the coniferous and broadleaved mixed forests, the correlation coefficient between the growth and competition of broadleaved species was greater than that of coniferous species. The dead trees were significantly influenced by competition. Tree relative vitality circle size was negatively correlated with DBH. The gravitational model was one of the critical models that reflect spatial interactions and could be applied to examine forest competition. The gravitational competition index could be used as a spatially structured indicator to evaluate tree competition and tree vitality, which could better indicate the relationship between tree growth and tree competition than the V_Hegyi competition index.

Occurrence and analysis of mycotoxins in domestic Chinese herbal medicines.

For time immemorial, Chinese herbal medicines (CHMs) have been widely used in China for disease treatment and promotion of general well-being. However, in recent years, many studies have shown that mycotoxins produced by fungi could contaminate CHMs due to unfavourable pre- or post-harvest conditions, raising major concern for consumer safety. At present, there is a significant focus on developing novel mycotoxin detection methods for analysing CHMs, and numerous studies have aimed to determine which kinds of raw herbal materials are most susceptible to mycotoxin contamination. In this review, we focus on recent advances in understanding and detection of mycotoxins in domestic raw herbal materials and related products from 2000 to 2018. Aspects of mycotoxin contamination of CHMs covered in this review include common mycotoxin contaminants in CHMs, maximum mycotoxin residue limits, analytical methods for mycotoxin detection and their applications and limitations, as well as a brief discussion of the trends in ongoing research.

A Review of Current Methods for Analysis of Mycotoxins in Herbal Medicines.

The presence of mycotoxins in herbal medicines is an established problem throughout the entire world. The sensitive and accurate analysis of mycotoxin in complicated matrices (e.g., herbs) typically involves challenging sample pretreatment procedures and an efficient detection instrument. However, although numerous reviews have been published regarding the occurrence of mycotoxins in herbal medicines, few of them provided a detailed summary of related analytical methods for mycotoxin determination. This review focuses on analytical techniques including sampling, extraction, cleanup, and detection for mycotoxin determination in herbal medicines established within the past ten years. Dedicated sections of this article address the significant developments in sample preparation, and highlight the importance of this procedure in the analytical technology. This review also summarizes conventional chromatographic techniques for mycotoxin qualification or quantitation, as well as recent studies regarding the development and application of screening assays such as enzyme-linked immunosorbent assays, lateral flow immunoassays, aptamer-based lateral flow assays, and cytometric bead arrays. The present work provides a good insight regarding the advanced research that has been done and closes with an indication of future demand for the emerging technologies.