HEATR3 involved in the cell proliferation, metastasis and cell cycle development of bladder cancer acts as a tumor suppressor.

The study was designed to detect the expression and clinical significance of the HEATR3 gene in bladder cancer (BCa) and to preliminarily explore whether this gene can affect the occurrence and development of BCa through the AKT/ERK signaling pathway. The expression and prognostic value of HEATR3 were explored based on The Cancer Genome Atlas (TCGA) and Genotypic Tissue Expression (GTEx) databases. Microarray immunohistochemical analysis was performed in 30 BCa cases to investigate the level of HEATR3 protein and to explore the relationship between HEATR3 and the clinicopathological features of BCa. Western Blot and qRT-PCR were used to detect HEATR3 protein and mRNA in BCa cell lines (5637, TCCSUP, SW780) and fallopian tube epithelial cell (SV-HUC-1). CCK8 method was employed to study the proliferation of BCa cells after heat treatment. Transwell assay was conducted to analyze the effect of HEATR3 on cell migration and invasion. And cell cycle and apoptosis were detected by flow cytometry. Furthermore, Western Blot assay was used to probe the effects of down-regulation of HEATR3 expression on the expression and phosphorylation levels of AKT and ERK proteins in BCa cells. Bioinformatics analysis showed that HEATR3 was significantly up-regulated in BCa, and high HEATR3 expression was associated with poor prognosis of BCa patients. In vitro experiments demonstrated that HEATR3 expression was up-regulated in BCa tissues compared with that in adjacent tissues. HEATR3 protein was also up-regulated in malignant cell lines. HEATR3 knockdown in BCa cells could inhibit cell proliferation, invasion and migration, block cell cycle and promote cell apoptosis. At the same time, HEATR3 knockdowns reduced the expression levels of p-AKT and p-ERK proteins. HEATR3 knockdown inhibits the development of BCa cells through the AKT/ERK signaling pathway. and it may become one of the most promising molecular targets for BCa treatment.

Genetic variation of pharmacogenomic VIP variants in the Chinese Li population: an updated research.

Previous studies have shown that the frequency of very important pharmacogenomic (VIP) genes varies in different populations which leads to the diversities in drug efficacy, safety, and the risk associated with adverse drug reactions (ADRs). The purpose of this study was to identify the distribution differences of VIP variants between the Li population and the other 13 populations. Based on the Pharmacogenomics Knowledgebase database (PhamGKB), we successfully genotyped 52 VIP variants within 27 genes in 200 unrelated Li population. χ2 test was used to evaluate the significant differences of genotype and allele frequencies between the Li and the other 13 populations from 1000 Genomes Project. Our study showed that the genotype frequencies of single nucleotide polymorphisms (SNPs) on KCNH2, ACE, CYP4F2, and CYP2E1 were considerably different between Li and the other 13 populations, especially in rs1805123 (KCNH2), rs4291 (ACE), rs3093105 (CYP4F2), and rs6413432 (CYP2E1) loci. Meanwhile, we found several VIP variants that might alter the drug metabolism of cisplatin-cyclophosphamide (CYP2E1), vitamin E (CYP4F2), asthma amlodipine, chlorthalidone, and lisinopril (ACE) through PharmGKB. We also identified other variants which were associated with adverse effects in isoniazid and rifampicin (CYP2E1; hepatotoxicity). The four loci rs1805123 (KCNH2), rs4291 (ACE), rs3093105 (CYP4F2), and rs6413432 (CYP2E1) provided a reliable basis for the prediction of the efficacy of certain drugs. The study complemented the existed pharmacogenomics information, which could provide theoretical basis for predicting the efficacy of certain drugs in the Li population.

Impact of genetic variants in IL-2RA and IL-2RB on breast cancer risk in Chinese Han women.

The expression of IL-2RA and IL-2RB was correlated with breast cancer (BC) progression. However, there is no literature investigating the association of IL-2RA and IL-2RB polymorphisms with BC predisposition among Chinese Han Women. Seven SNPs in IL-2RA and IL-2RB were genotyped by Agena MassARRAY platform among 553 BC patients and 550 healthy controls. Odds ratios (OR) and 95% confidence interval (CI) adjusted for age were calculated for the effect of IL-2RA and IL-2RB variants on BC susceptibility. IL-2RA rs12722498 was a protective factor for BC occurrence (OR = 0.70, p = 0.019), especially in subjects with age ≤ 52 years (OR = 0.55, p = 0.004). IL-2RA rs12569923 (OR = 9.07, p = 0.033), IL-2RB rs2281089 (OR = 0.67, p = 0.043) and rs9607418 (OR = 0.59, p = 0.012) were related to the incidence of estrogen receptor positive (ER +) BC. IL-2RB rs3218264 (OR = 1.38, p = 0.010) and rs9607418 (OR = 0.56, p = 0.009) were associated with the risk of developing progesterone receptor positive (PR +) BC. Rs2281089 (OR = 1.54, p = 0.012) and rs1573673 (OR = 0.72, p = 0.035) were correlated to Ki-67 level. Moreover, IL-2RB rs2281089 (OR = 0.72, p = 0.022) showed a reduced risk of BC metastasis, and IL-2RA rs12722498 (OR = 0.54, p = 0.030) had a lower frequency in BC patients with tumor size > 2 cm. Our study identified the potential effect of genetic variations in IL-2RA and IL-2RB on BC susceptibility and/or BC clinicopathologic indicators among Chinese Han Women.

Modeling the structure and infrared spectra of omega-3 fatty acid esters.

Omega-3 dietary supplements provide a rich source of the active moieties eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which exist in the form of triacylglycerols or ethyl esters. Infrared (IR) spectroscopy provides a rapid and quantitative tool to assess the quality of these products as specific normal modes, in particular the ester carbonyl stretch modes, exhibit characteristic spectral features for the two ester forms of omega-3 fatty acids. To uncover the origin of the observed spectra, in this work, we perform molecular dynamics simulations of EPA and DHA ethyl esters and triacylglycerols to characterize their conformation, packing, and dynamics in the liquid phase and use a mixed quantum/classical approach to calculate their IR absorption spectra in the ester carbonyl stretch region. We show that the ester liquids exhibit slow dynamics in spectral diffusion and translational and rotational motion, consistent with the diffusion ordered NMR spectroscopy measurements. We further demonstrate that the predicted IR spectra are in good agreement with experiments and reveal how a competition between intermolecular and intramolecular interactions gives rise to distinct absorption peaks for the fatty acid esters.

Effects of Ninjurin 2 polymorphisms on susceptibility to coronary heart disease.

OBJECTIVE: The aim of this study was to explore the effects of Ninjurin 2 (NINJ2) polymorphisms on susceptibility to coronary heart disease (CHD). METHODS: We conducted a case-control study with 499 CHD cases and 505 age and gender-matched controls. Five single nucleotide polymorphisms (SNPs) in NINJ2 (rs118050317, rs75750647, rs7307242, rs10849390, and rs11610368) were genotyped by the Agena MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression analysis to assess the association of NINJ2 polymorphisms and CHD risk-adjusted for age and gender. What's more, risk genes and molecular functions were screened via protein-protein interaction (PPI) network and functional enrichment analysis. RESULTS: Rs118050317 in NINJ2 significantly increased CHD risk in people aged more than 60 years and women. Rs118050317 and rs7307242 had strong relationships with hypertension risk in CHD patients. Additionally, rs75750647 exceedingly raised diabetes risk in cases under multiple models, whereas rs10849390 could protect CHD patients from diabetes in allele, homozygote, and additive models. We also observed two blocks in NINJ2. Further interaction network and enrichment analysis showed that NINJ2 played a greater role in the pathogenesis and progression of CHD. CONCLUSION: Our results suggest that NINJ2 polymorphisms are associated with CHD risk.

Organocatalytic asymmetric one-pot sequential conjugate addition/dearomative fluorination: synthesis of chiral fluorinated isoxazol-5(4H)-ones.

A facile one-pot sequential conjugate addition/dearomative fluorination transformation of isoxazol-5(4H)-ones with nitroolefins and N-fluorobenzenesulfonimide (NFSI) has been developed. By using a bifunctional chiral tertiary amino-thiourea catalyst, a series of chiral fluorinated isoxazol-5(4H)-ones containing one fluorine-substituted quarternary stereocenter were obtained in high yields with high enantio- and diastereoselectivities. Further transformation of adducts could afford isoxazolidin-5-one derivatives with three contiguous stereocenters.

Empirical versus tailored therapy based on genotypic resistance detection for Helicobacter pylori eradication: a systematic review and meta-analysis.

Background: The eradication rate of Helicobacter pylori infection with empirical therapy has decreased due to increased drug resistance. The latest guidelines recommend genotypic resistance-guided therapy, but its clinical efficacy remains unclear. Objectives: The purpose of our study was to evaluate whether tailored therapy based on genotypic resistance is superior to empirical therapy for H. pylori infection. Design: A systematic review and meta-analysis of randomized controlled trials (RCTs) comparing tailored therapy based on genotypic resistance with empirical therapy was performed. Sources and methods: We retrieved relevant studies from PubMed, Embase, and the Cochrane Library. The primary outcome was H. pylori eradication rate and the adverse events (AEs) was the secondary outcome. A random-effect model was applied to compare pooled risk ratios (RRs) with related 95% confidence intervals (CIs). Results: A total of 12 qualified RCTs containing 3940 patients were identified in our systematic review and meta-analysis. The pooled eradication rates of tailored therapy based on the detection of genotypic resistance were consistently higher than those in the empirical treatment group, with no statistical significance. In triple therapy, the eradication rate was significantly higher in the tailored group than in the empirical group by intention-to-treat analysis (ITT) and per-protocol analysis (PP) analysis (p < 0.0001, RR: 1.20; 95% CI: 1.12-1.29; p < 0.0001, RR: 1.20; 95% CI: 1.15-1.25). In quadruple therapy, the eradication rate was higher in the empirical group (p = 0.001, RR: 0.93; 95% CI: 0.89-0.97; p = 0.009, RR: 0.95; 95% CI: 0.92-0.99). And this result was true for both bismuth quadruple therapy (BQT) and non-BQT. Regarding total AEs, the pooled rate was 34% in the tailored group and 37% in the empirical group, and no difference between the two groups was found (p = 0.17, RR: 0.88; 95% CI: 0.74-1.06). Conclusion: In conclusion, tailored therapy based on molecular methods may offer better efficacy than empirical triple therapy, but it may not be superior to empirical quadruple therapy in eradicating H. pylori infection. Larger and more individualized RCTs are needed to aid clinical decision-making. Registration PROSPERO: CRD42023408688.

Modeling the Infrared Spectroscopy of Oligonucleotides with 13C Isotope Labels.

The carbonyl stretching modes have been widely used in linear and two-dimensional infrared (IR) spectroscopy to probe the conformation, interaction, and biological functions of nucleic acids. However, due to their universal appearance in nucleobases, the IR absorption bands of nucleic acids are often highly congested in the 1600-1800 cm-1 region. Following the fruitful applications in proteins, 13C isotope labels have been introduced to the IR measurements of oligonucleotides to reveal their site-specific structural fluctuations and hydrogen bonding conditions. In this work, we combine recently developed frequency and coupling maps to develop a theoretical strategy that models the IR spectra of oligonucleotides with 13C labels directly from molecular dynamics simulations. We apply the theoretical method to nucleoside 5'-monophosphates and DNA double helices and demonstrate how elements of the vibrational Hamiltonian determine the spectral features and their changes upon isotope labeling. Using the double helices as examples, we show that the calculated IR spectra are in good agreement with experiments and the 13C isotope labeling technique can potentially be applied to characterize the stacking configurations and secondary structures of nucleic acids.

Very important pharmacogenes polymorphism landscape and potential clinical relevance in the Chinese Mongolian.

PURPOSE: Our study genotyped pharmacogenes in 200 individuals from Inner Mongolia Autonomous Region, China. Aim to find distinct pharmacogenomic variations among the Mongolian population and to investigate the potential clinically operable gene-drug connection and genotype-phenotype correlation of differential variation in the Mongolian population. METHODS: We sampled 61 variations of 28 genes in PharmGKB and genotyped them using Agena MassARRAY Assay. We also obtained the allele frequency and genotype distribution data of 26 populations from the 1000 Genomes Project (1000G), and then conducted comparison and statistical analysis. RESULTS: After Bonferroni correction, there were significant genotype frequency distribution differences between the Mongolian and 26 populations: PTGS2 (rs20417), NAT2 (rs1801280, rs1799929, and rs1208), ALOX5(rs2115819), and CYP2D6 (rs1065852). It was also found that the KHV showed the smallest differences from the Mongolian and the GWD showed the largest differences. Furthermore, the differences in variants might be related to the risk of non-steroidal anti-inflammatory drug use, the slow acetylation phenotype, and other pharmacological effectiveness and toxicity in the Mongolian population. CONCLUSION: Our study demonstrates different pharmacogenomic variants in the Mongolian and fills the gaps in pharmacogenomic information of the Mongolian. Our analysis of VIPs variants in the Mongolian population may contribute to the development of safer treatment regimens and the use of personalized treatment approaches.

Measuring the Enthalpy of an Individual Hydrogen Bond in a DNA Duplex with Nucleobase Isotope Editing and Variable-Temperature Infrared Spectroscopy.

The level of interest in probing the strength of noncovalent interactions in DNA duplexes is high, as these weak forces dictate the range of suprastructures the double helix adopts under different conditions, in turn directly impacting the biological functions and industrial applications of duplexes that require making and breaking them to access the genetic code. However, few experimental tools can measure these weak forces embedded within large biological suprastructures in the native solution environment. Here, we develop experimental methods for detecting the presence of a single noncovalent interaction [a hydrogen bond (H-bond)] within a large DNA duplex in solution and measure its formation enthalpy (ΔHf). We report that introduction of a H-bond into the TC2═O group from the noncanonical nucleobase 2-aminopurine produces an expected decrease ∼10 ± 0.76 cm-1 (from ∼1720 cm-1 in Watson-Crick to ∼1710 cm-1 in 2-aminopurine), which correlates with an enthalpy of ∼0.93 ± 0.066 kcal/mol for this interaction.

Evaluation of different deep convolutional neural networks for detection of broadleaf weed seedlings in wheat.

BACKGROUND: In-field weed detection in wheat (Triticum aestivum L.) is challenging due to the occurrence of weeds in close proximity with the crop. The objective of this research was to evaluate the feasibility of using deep convolutional neural networks for detecting broadleaf weed seedlings growing in wheat. RESULTS: The object detection neural networks, including CenterNet, Faster R-CNN, TridenNet, VFNet, and You Only Look Once Version 3 (YOLOv3) were insufficient for weed detection in wheat because the recall never exceeded 0.58 in the testing dataset. The image classification neural networks including AlexNet, DenseNet, ResNet, and VGGNet were trained with small (5500 negative and 5500 positive images) or large training datasets (11 000 negative and 11 000 positive images) and three training image sizes (200 × 200, 300 × 300, and 400 × 400 pixels). For the small training dataset, increasing image sizes decreased the F1 scores of AlexNet and VGGNet but generally increased the F1 scores of DenseNet and ResNet. For the large training dataset, no obvious difference was detected between the training image sizes since all neural networks exhibited remarkable classification accuracies with high F1 scores (≥0.96). All image classification neural networks exhibited high F1 scores (≥0.99) when trained with the large training dataset and the training images of 200 × 200 pixels. CONCLUSION: CenterNet, Faster R-CNN, TridentNet, VFNet, and YOLOv3 were insufficient, while AlexNet, DenseNet, ResNet, and VGGNet trained with a large training dataset were highly effective for detection of broadleaf weed seedlings in wheat. © 2021 Society of Chemical Industry.

Analysis of pharmacogenomic very important pharmacogenomic variants: CYP3A5, ACE, PTGS2 and NAT2 genes in Chinese Bai population.

Aim: Our study aimed to screen the genotype frequencies of very important pharmacogenomic (VIP) mutations and identify their differences between Bai and other populations. Materials & methods: We selected 66 VIP variants from PharmGKB (www.pharmgkb.org/) for genotyping. χ2 test was used to identify differences in loci between these populations and FST values of Bai and the other 26 populations were analyzed. Results: Our study showed that the frequencies of SNPs of CYP3A5, ACE, PTGS2 and NAT2 differed significantly from those of the other 26 populations. At the same time, we found that some VIP variants may affect the metabolism of drugs and the genetic relationship between the Bai population and East Asian populations was found to be the closest. Conclusion: By comparing the genotype frequencies of different populations, the loci with significant differences were identified and discussed, providing a theoretical basis for individualized drug use in the Bai ethnic population.

Genetic polymorphisms of pharmacogenomic VIP variants in the Lahu population from Yunnan Province.

BACKGROUND: Pharmacogenomics has been widely used to study the very important pharmacogenetic (VIP) variants among populations, but information on pharmacogenomics in the Lahu population is limited. The purpose of this study was to determine the differences in the distribution of VIP variants between the Lahu and the other 26 populations. METHODS: We genotyped 55 VIP variants of 27 genes in the Lahu population from the PharmGKB database. χ2 test was used to compare the genotype and allele frequencies between the Lahu and the other 26 populations from the 1000 Genomes Project. RESULTS: The genotype and allele frequencies of single nucleotide polymorphisms (SNPs) on rs20417 (PTGS2), rs776746 (CYP3A5), rs2115819 (ALOX5), and rs3093105 (CYP4F2) were considerably different in the Lahu population compared with those in the other 26 populations. Besides, based on the PharmGKB database, we identified several VIP variants that may alter the drug metabolism of aspirin (PTGS2), tacrolimus (CYP3A5), montelukast (ALOX5), and vitamin E (CYP4F2). CONCLUSION: The results show that there are significant differences in the genotype frequency distribution between the Lahu and the other 26 populations. Our study supplements the pharmacogenomics information of the Lahu population and provides a theoretical basis for individualized medicine in Lahu.

Are People Altruistic When Making Socially Responsible Investments? Evidence From a tDCS Study.

Socially responsible investment (SRI) is an emerging philosophy that integrates social and environmental impacts into investment considerations, and it has gradually developed into an important form of investment. Previous studies have shown that both financial and non-financial motivations account for SRI behaviors, but it is unclear whether the non-financial motive to adopt SRI derives from investors' altruism. This study uses neuroscientific techniques to explore the role of altruism in SRI decision-making. Given that existing evidence has supported the involvement of the right temporoparietal junction (rTPJ) in altruism and altruistic behaviors, we used transcranial direct current stimulation (tDCS) to temporarily modulate activity in the rTPJ and tested its effect on charitable donations and SRI behaviors. We found that anodal stimulation increased the subjects' donations, while cathodal stimulation decreased them, suggesting that tDCS changed the subjects' levels of altruism. More importantly, anodal stimulation enhanced the subjects' willingness to make SRIs, while cathodal stimulation did not have a significant impact. These findings indicate that altruism plays an important role in SRI decision-making. Furthermore, cathodal stimulation changed the subjects' perceived effectiveness of charitable donation but not that of socially responsible fund. This result may help explain the inconsistent effects of cathodal stimulation on charitable donations and SRI behaviors. The main contribution of our study lies in its pioneering application of tDCS to conduct research on SRI behaviors and provision of neuroscientific evidence regarding the role of altruism in SRI decision-making.

Simultaneous qualitative and quantitative analysis of 21 mycotoxins in Radix Paeoniae Alba by ultra-high performance liquid chromatography quadrupole linear ion trap mass spectrometry and QuEChERS for sample preparation.

A high-throughput method for simultaneous qualitative and quantitative analysis of 21 mycotoxins in Radix Paeoniae Alba (RPA) was developed by coupling the modified QuEChERS method with ultra-high performance liquid chromatography quadrupole linear ion trap mass spectrometry (UHPLC-QqLIT-MS). The 21 mycotoxins were extracted and cleaned up using QuEChERS-based procedure, then further separated on a C18 column and detected by a hybrid triple quadrupole linear ion trap mass spectrometer equipped with electrospray ionization source in the multiple reaction monitoring-information dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode. Under this technique, 13 mycotoxins were detected using acetonitrile and water containing 0.1% formic acid as the mobile phase in positive mode while the other 8 mycotoxins were detected using acetonitrile and water containing 0.1% ammonia as the mobile phase in negative mode. The calibration curves of all analytes showed good linearity (r(2)>0.995) within test ranges. The limits of detection and quantification ranged from 0.031 to 5.4µg/kg and 0.20 to 22µg/kg, respectively. Additionally, recoveries were all above 75.3% with relative standard deviations within 15%. The method proposed herein with significant advantages including simple pretreatment, rapid determination as well as high sensitivity, accuracy and throughput would be a preferred candidate for the determination and quantification of multi-class mycotoxin contaminants in real samples.

Comparison of two extraction methods for the determination of 135 pesticides in Corydalis Rhizoma, Chuanxiong Rhizoma and Angelicae Sinensis Radix by liquid chromatography-triple quadrupole-mass spectrometry. Application to the roots and rhizomes of Chinese herbal medicines.

In this study, two simple pretreatment methods were comprehensively evaluated for the determination of 135 pesticide residues in roots and rhizomes of Chinese herbal medicines (CHMs). The studied methodologies are (a) solid-phase extraction (SPE) and (b) Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS). For SPE, extraction solvents, SPE cartridges and types and volume of eluent were accessed and optimized. For QuEChERS, different versions, acetic acid concentration and dispersive solid-phase extraction (dSPE) sorbent materials were tested. SPE and QuEChERS were estimated in recovery range, the number of pesticides that were recovered ranging from 90% to 110% and expenses in Corydalis Rhizoma, Chuanxiong Rhizoma and Angelicae Sinensis Radix. QuEChERS method showed better performance than SPE. The method showed good linearity over the range assayed 0.9986-0.9999 (1-80ng/mL for 124 pesticides, 1-50ng/mL for 10 pesticides, 1-20ng/mL for satisfar). The matrix effect was compensated by matrix-based calibration curves with internal standard. The average recoveries of all pesticides were ranging from 70% to 120% at three levels of 10, 50 and 100ng/g with relative standard deviations less than 20%. The limits of quantification of the 135 pesticides in three matrices were 1-5ng/g, which were below the maximum residue levels (MRLs) established by the European Union. The verified QuEChERS method was successfully applied to the analysis of 65 actual samples from eight different types of roots and rhizomes of CHMs. Angelicae Sinensis Radix was the most susceptible to pesticides among these samples, and the most frequently detected pesticide was carbendazim with levels below MRLs. Metalaxyl, phorate, atrazine, diniconazole, coumaphos and paclobutrazol were also detected in some samples.

A multi-residue method for simultaneous determination of 74 pesticides in Chinese material medica using modified QuEChERS sample preparation procedure and gas chromatography tandem mass spectrometry.

The present study is focused on the development of an analytical method for the simultaneous analysis of seventy-four pesticides belonging to different chemical classes (organochlorines, organophosphates, pyrethroids, dinitroanilines, dicarboximides, triazoles, etc.) in Chinese material medica. The samples were extracted according to the acetate QuEChERS protocol. To reduce the amount of co-extracted compounds, n-hexane instead of acetonitrile was employed as the extraction solvent. To improve the overall recoveries of problematic basic and base-sensitive compounds, sodium acetate was used to adjust the pH to a neutral condition, and florisil combined with octadecyl-modified silica (C18) were utilized in the cleanup step. The samples were analysed by GC-MS/MS, and quantified by matrix-matched calibration. The validation study was carried out on two representative herbs, Chuanxiong Rhizoma and Angelica Sinensis Radix. In two matrices, the linearity of the calibration was good between 5 and 250 ng/mL concentration ranges, and the limits of quantification (LOQs) less than 0.01 mg/kg for most pesticides. At the LOQs and ten times the LOQs, the mean recoveries of almost all pesticides were within 70-120%, with relative standard deviations (RSDs) lower than 10%. The method was applied on twenty real samples. Seven batches of Chuanxiong and five batches of Danggui were found to contain the residues. The combination of modified QuEChERS and GC-MS/MS offers low cost of analysis as well as excellent accuracy and sensitivity. This method could be especially useful for trace analysis of pesticide residues in complex matrices.

[Determination of 99 pesticide residues in Paeoniae Radix Alba by gas chromatography-triple quadrupole tandem mass spectrometry].

A method was established for the simultaneous determination of 99 pesticide residues with combination of solid-phase extraction technique ( SPE) and gas chromatography-triple quadrupole tandem mass spectrometry (GC-QqQ-MS). The sample was extracted with ethyl acetate, and cleaned-up by an amino SPE column. The extract was determined by GC-MS/MS in multi-reaction monitoring (MRM) mode, and matrix-matched internal standard method was applied to quantify the pesticides. The results of all the 99 pesticides showed good linearity in the range of 0.001-0.25 mg/L, with correlation coefficients (r2) > 0.99. The limits of quantification (LOQs) were between 0.001-0.050 mg/kg. The recoveries were between 66.7% and 128.0% with RSD values typically lower than 18.3% at three spiked levels of 0.05, 0.10 and 0.20 mg/kg. This method has been applied to determine thirteen batches of commercially available samples, chlorpyriphos-ethyl and p,p'-DDE were detected in four batches of Paeoniae Radix Alba. The method is highly accurate, reliable and sensitive for monitoring the 99 pesticide residues in Paeoniae Radix Alba.

[Determination of 135 pesticides and their metabolites in Angelica sinensis by ultra-fast liquid chromatography-tandem mass spectrometry coupled with solid-phase extraction].

A method using solid-phase extraction (SPE) followed by ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) has been established for simultaneously quantitative determination of 135 pesticides and their metabolites (organophosphorus pesticides, pyrethroid pesticides and carbamate pesticides, etc.) in Angelica sinensis. The pesticide residues were extracted from the samples by acetonitrile, cleaned-up with a primary secondary amine (PSA) column and then analyzed using UFLC-MS/MS in multiple reaction monitoring (MRM) mode with positive electrospray ionization. The pesticide residues were quantified by matrix matched standard solution-internal standard method. All of the pesticides had good linear responses with r > 0.99. The average recoveries of the pesticides at the spiked levels of 10, 50, 100 µg/kg ranged from 71.3% - 119.7% with the RSDs of 1.0% - 19.9%, except for clethodim (62.0% - 68.2%). The limits of quantification of the 135 pesticides and their metabolites were 1.0-10.0 µg/kg. The results demonstrated that the method is simple, fast, sensitive and can be used for the analysis of the multiclass of pesticide residues in Angelica sinensis.