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ObjectiveBased on ultra performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry（UPLC-Q-TOF-MS）， to evaluate the establishment of a mouse model of liver Yin deficiency by thyroid tablet suspension combined with 10% carbon tetrachloride（CCl4） from the perspective of non-targeted metabolomics， in order to lay the foundation for the establishment of a traditional Chinese medicine（TCM） syndrome model. MethodA total of 24 mice were randomly divided into blank group and model group. The model group was given thyroid tablet suspension（0.003 2 g·kg-1） by gavage for 14 consecutive days， and 10% CCl4（5 mL·kg-1） was intraperitoneally injected once a week to establish a liver Yin deficiency model， while the blank group was injected with an equal amount of olive oil intraperitoneally and gavaged with an equal amount of distilled water， and was fed with normal feed. After the modeling was completed， 6 mice in each group were randomly selected， the levels of alanine aminotransferase（ALT）， aspartate aminotransferase（AST）， cyclic adenosine monophosphate（cAMP）， cyclic guanosine monophosphate（cGMP）， interleukin（IL）-6， IL-10， tumor necrosis factor-α（TNF-α）were measured in the mice serum， and malondialdehyde（MDA）， superoxide dismutase（SOD）， total protein（TP）， hydroxyproline（HYP） and other indicators were measured in the mice liver. Liver tissue sections were taken for hematoxylin-eosin（HE） staining and observing pathological changes. The remaining 6 mice in each group were subjected to UPLC-Q-TOF-MS combined with principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to screen differential metabolites in the liver Yin deficiency mouse model， Kyoto Encyclopedia of Genes and Genomes（KEGG） database was used to analyze the corresponding metabolic pathways of differential metabolites. ResultCompared with the blank group， mice in the model group showed liver Yin deficiency manifestations such as reduced body weight， fatigue and sleepiness， disheveled and lusterless hair， irritability. The levels of ALT， cAMP/cGMP， IL-6， AST， MDA， cAMP， TNF-α significantly increased（P<0.05， P<0.01）， while the levels of SOD， IL-10 and cGMP significantly decreased（P<0.05， P<0.01）， and the changes of HYP and TP were not statistically significant. Hepatic steatosis and distortion of the radial arrangement of the liver plate cells were seen in the section images of the model group， endogenous substances were clearly separated， and 252 differential metabolites were identified in the serum samples， which were mainly involved in the metabolic pathways of purine metabolism， steroid hormone biosynthesis and pyrimidine metabolism. A total of 229 differential metabolites were identified in the liver samples， mainly involving nucleotide metabolism， purine metabolism， steroid hormone biosynthesis， pyrimidine metabolism， antifolate resistance， insulin resistance， primary bile acid biosynthesis， prostate cancer， sulfur relay system， arachidonic acid metabolism and other metabolic pathways. ConclusionThe successful establishment of liver Yin deficiency model in mice by CCl4 combined with thyroid hormone is evaluated through the investigation of serum and liver metabolomics， combined with biochemical indicators， which provides a biological basis and experimental foundation for the Yin deficiency syndrome model of TCM.
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Background Dicamba is widely used in agricultural production in China, but it is extremely soluble in water and can be harmful to human health when it enters the body via water drinking. It is necessary to establish an accurate, sensitive, and rapid detection method to determine the residues of dicamba in domestic drinking water. Objective To establish two methods for the determination of dicamba residues in drinking water by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) respectively. Methods The conditions of the proposed method using HPLC-MS/MS included CAPCELL PAK ST chromatographic column, ammonium formate water solution and methanol as the mobile phase, and isocratic elution. The system was operated under multiple reaction monitoring mode and electrospray negative ionization mode. Trimethylsilylated diazomethane was used as a derivatizing agent for GC-MS/MS, and an external standard curve was used to evaluate the system. The residues of dicamba in seven water samples of tap water or secondary water supply from six regions in Chengdu were detected by the established systems to evaluate their applicability and to understand the status quo of dicamba residues in drinking water. Results For the HPLC-MS/MS, the linear range of dicamba was 1.00-100 μg·L−1, the regression equation was \begin{document}$\hat Y $\end{document}=1250.9X+2681.5, the correlation coefficient was 0.9988, the relative standard deviations were 1.23%-26.3%, the limit of detection was 0.95 μg·L−1, and the spiked recoveries were 91.8%-111%. For the GC-MS/MS, the linear range of dicamba was 0.200-10.0 μg·L−1, the regression equation was \begin{document}$\hat Y $\end{document}=190597X+40911, the correlation coefficient was 0.9993, the relative standard deviations were 0.64%-3.90%, the limit of detection was 0.18 μg·L−1, and the spiked recoveries were 97.3%-105%. No dicamba residue was identified in the seven water samples of tap water or secondary water supply from six regions in Chengdu by the proposed methods. Conclusion The two detection methods established in this study are sensitive and rapid, meet the requirements from the detection of dicamba residues in drinking water, and provide an experimental basis for subsequent research on the detection of dicamba residues. In the future, it is necessary to continue to pay attention to the pollution of dicamba in drinking water in Chengdu.
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Objective To establish a direct extraction ultra-high performance liquid chromatography tandem mass spectrometry method for the determination of bongkrekic acid in corn flour. Methods Bongkrekic acid was directly extracted with 80% methanol from corn flour samples, and the supernatant after vortex and centrifugation was determined after passing through membrane filtration. At the same time, the corn flour samples were extracted by solid phase extraction. The determination results of the two methods were compared. Results The linearity of standard series was good within the range of2-20 μg/L, and the linearity coefficient was＞0.999. The determination result of the positive sample by direct extraction method was 193.40 mg/kg (n=6). Adding the standard to the blank sample at the levels of 2, 6, and 10 μg/L, the calculated recovery rate was 75.82% - 99.33%, and the relative standard deviation was 3.54 % - 8.45%. The detection limit of the method reached 6 μg/kg. After extraction by solid phase extraction, the determination result of the positive sample was 196.84 mg/kg (n=6). The recovery rate was 77.12% -100.83%, with a relative standard deviation of 8.32% - 9.54%. Conclusion Compared with the solid phase extraction, the direct extraction method for the extraction of bongkrekic acid from corn flour has the advantages of rapidity, simplicity, and cost savings.
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Objective To investigate the differential metabolites of lymph node metastasis in pancreatic ductal carcinoma (PDAC) and provide new ideas for the pathogenesis, early diagnosis and treatment of metastatic pancreatic cancer. Methods Forty serum specimens of patients with pancreatic ductal carcinoma were collected and divided into lymph node metastasis group (18 cases) and non-metastasis group (22 cases). Thirty-one serum specimens were also collected from the healthy control group. Liquid chromatographytandem mass spectrometry was used to analyze the differential metabolites and metabolic pathways between patients with PDAC and healthy controls as well as between lymph node metastasis and non-metastasis groups. Results Principal component analysis and partial least squares-discriminant analysis revealed statistically significant differences in metabolites and metabolic pathways between patients with PDAC and the healthy controls and between lymph node metastasis and non-metastasis groups. The differences in profiles were also statistically significant. Seventy-six different metabolites and 11 metabolic pathways were screened between patients with PDAC and the healthy controls, among which phenylalanine metabolism and histidine metabolism were the two most influential metabolic pathways. Four different metabolites were screened between lymph node metastasis and non-metastasis groups, and the expression of ethopropazine and phenylalanine were upregulated but the expression of tetrahydrodeoxycorticosterone and oxprenolol were downregulated. Conclusion Metabolites are significantly altered in the lymph node metastasis group of patients with PDAC compared with the non-metastasis group. Ethopropazine, phenylalanine, tetrahydrodeoxy corticosterone, and oxprenolol are potential biomarkers of lymph node metastasis in patients with PDAC.
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Objective@#To optimize the determination of pentachlorophenol in wooden chopping boards through pretreatment of miniaturized samples.@*Methods@# The pretreated wooden chopping board samples were subjected to ultrasound extraction (1 mL of 0.5 mol/L K2CO3 added in 5 mL extraction solution) in 8 mL acetone and 2 mL water, followed by derivatization with 0.3 mL acetic anhydride, extraction with n-hexane and separation with DB-5ms column (30 m×0.25 mm, 0.25 μm). Gas chromatography tandem mass spectrometry (GC-MS/MS) was performed in multiple reaction monitoring (MRM) mode with quantitative analysis using the internal standard method.@*Results@#The GC-MS/MS assay showed a good linear relationship within the range of 0.01 to 0.2 µg/mL (R2>0.999), with a 0.003 mg/kg limit of detection and 0.01 mg/kg limit of quantitation. The mean recovery rates were 84.2% to 96.7% at spiked concentrations of 0.003, 0.01 and 0.03 mg/kg, with relative standard deviation of 2.2% to 6.1%.@*Conclusions@#The established GC-MS/MS assay is easy to perform, environment-friendly, highly accurate and sensitivity, which is feasible for determination of pentachlorophenol in wooden chopping boards.
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Objective:High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to quantify the levels of vitamins A, D and E in pregnant women during the second trimester, and to investigate the change trends of serum vitamins A, D and E levels during pregnancy.Method:A total of 720 pregnant women with an average age of (29.7±4.4) years and 12-22 weeks of gestation were included from October 1, 2021 to October 30, 2022 in the obstetrics department of the People′s Hospital of Wuhan University. The concentrations of vitamins A, D and E were determined by HPLC-MS/MS. The concentration levels of each group were statistically analyzed and the deficiency rate were calculated.Results:The distribution range of vitamin A, D and E (95% CI) was 0.74-2.74 μmol/L, 2.88-25.37 ng/ml and 6.18-35.08 μmol/L, with the deficiency rates were 9.30%, 93.76% and 35.83%, respectively. Vitamin A, D and E levels in the twin group were (1.67±0.51) μmol/L, (13.18±7.44) ng/ml and 11.97 (8.85, 14.60) μmol/L, respectively. They were significantly higher than those in the singlet group (1.45±0.36) μmol/L, (10.87±5.26) ng/ml and 10.46 (6.99, 14.11) μmol/L, with statistical significance by independent sample t-test ( P<0.001). The concentration of vitamin D in the lower BMI group (<22 kg/m 2) was (12.54±5.74) ng/ml, significantly higher than that in the fat group (≥22 kg/m 2) (10.46±4.90) ng/ml, and the rank-sum test was statistically significant ( P<0.001). Conclusion:In this study, the levels of three vitamins were monitored in mid-pregnancy using HPLC-MS/MS, and the changes of serum vitamin A, D, and E levels during pregnancy were analyzed.
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Objective:To establish and validate a reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of 12 ceramides in human plasma.Methods:From October 2021 to October 2022, 438 apparently healthy individuals were enrolled in the Affiliated Hospitals of Zunyi Medical University for reference intervals of 12 ceramides in this population. Plasma samples were collected, and separated using the ACQUITY UPLC BEH C18 (2.1×50 mm, 1.7 μm) column, deuterated isotopes were used as internal standards. The mobile phase is water (containing 0.1% formic acid) and isopropanol: acetonitrile (1∶1, v/v, containing 0.1% formic acid) at a flow rate of 0.4 ml/min with gradient elution. The detection method was established using the Qlife Lab 9000 Plus triple quadrupole mass spectrometer. The performance of the method was evaluated in terms of linearity, the lower limit of quantification, precision, recovery, and stability.Results:The method passed the performance evaluation in terms of linearity, the lower limit of quantification, recovery, precision, and stability. The intra-and inter-batch precision of the 12 ceramides ranged from 1.3% to 14.3%, the correctness was verified by spiked recovery experiments, and the recoveries ranged from 91.9% to 111.0%. The lower limit of quantification ranged from 0.001 to 0.100 μmol/L. Standard curve showed good linearity (correlation coefficient r>0.990). Stability tests showed that the 12 ceramides were stable in the biological matrix and after processing under different conditions for a specified period of time. The corresponding biological reference intervals were established for each of the 12 ceramides: 0.103-0.326 μmol/L for Cer(d18∶1/16∶0), 0.018-0.098 μmol/L for Cer(d18∶1/18∶0), 0.933-3.919 μmol/L for Cer(d18∶1/24∶0), 0.243-1.072 μmol/L for Cer(d18∶1/24∶1), 0.001-0.007 μmol/L for Cer(d18∶1/14∶0), 0.022-0.095 μmol/L for Cer(d18∶1/20∶0), 0.185-0.835 μmol/L for Cer(d18∶1/22∶0), 0.003-0.022 μmol/L for Cer(d18∶0/16∶0), 0.001-0.016 μmol/L for Cer(d18∶0/18∶0), 0.017-0.156 μmol/L for Cer(d18∶0/24∶0), 0.008-0.074 μmol/L for Cer(d18∶0/24∶1), and 0.106-0.721 μmol/L for LacCer(d18∶1/24∶1). Conclusion:Our study shows that the newly established LC-MS/MS method for the determination of 12 ceramides in human plasma is reliable, and suitable for clinical application.
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Objective:To establish an isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method for the determination of L-tryptophan and its metabolites in serum.Methods:The methodology was established and evaluated using serum samples collected from 166 healthy subjects undergoing physical examinations at West China Hospital from November 2022 to January 2023 were collected. Isotope-labeled markers of L-tryptophan (Trp), L-kynurenine (Kyn), and kynurenic acid (KA) were used as internal standards. After protein precipitation treatment of serum samples, LC-MS/MS was used to determine Trp, Kyn, and KA simultaneously. The selectivity, specificity, linearity, detection limit (LOD), quantification limit (LOQ), carry-over, precision, recovery rate, matrix effect, and dilution integrity of the method were evaluated.Results:The linearity of Trp, Kyn, and KA was demonstrated to be 0.999. The LODs were 0.10 μmol/L, 0.01 μmol/L and 1.00 nmol/L, respectively. The LOQs were 0.20 μmol/L, 0.04 μmol/L and 2.00 nmol/L, respectively. The intra-batch precision and inter-batch precision were below<10%. The average recovery rate and the relative matrix effect were all about 100%. The samples over the upper limit of quantitation can be diluted up to 16 times. The Trp concentration, Kyn concentration, KA concentration, Kyn/Trp ratio, and KA/Kyn ratio in serum of healthy subjects were 59.55±10.92 μmol/L, 1.85±0.43 μmol/L, 39.89±17.93 nmol/L, (31.64±8.19)×10 -3 and 21.51±6.72, respectively. Conclusion:An ID-LC-MS/MS method was successfully established for the quantitative determination of Trp, Kyn, and KA in serum. The method proved to be simple, rapid, sensitive, accurate, and reliable, providing robust support for clinical research related to these analytes.
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Objective:To establish and validate an LC-MS/MS method for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in cerebrospinal fluid. Additionally, the consistency between this method and three mainstream detection methods was evaluated.Methods:This study involved method establishment, validation, and consistency evaluation. The N15 labeled β-amyloid protein was used as the internal standard. Extraction was performed using Waters MCX 96-wells solid phase extraction plate, and the eluent was collected to QuanRecovery MaxPeak 700 μl plate. At the positive ion mode, the multi-reaction ion monitoring mode based on electric spray ionization is chosen for the determination of CSF Aβ 1-42, Aβ 1-40, and Aβ 1-38. Referring to the CLSI C62-A and EP-15A3 guidelines, the method is evaluated and verified, including quantitation of limit (LOQ), linearity, recovery, precision, and accuracy. In addition, a total of 57 clinical residual CSF samples were collected and the concentrations of Aβ 1-42 and Aβ 1-40 were determined based on manual INNOTEST ELISA assay and Lumipulse G and Roche Elecsys fully automated biochemical analyzers. The comparison analysis and deviation evaluation were conducted by passing-bablok and Bland Altman methods.Results:The analysis time of this method is 8 min, and the LOQ of Aβ 1-42, Aβ1-40 and Aβ1-38 is 0.1 ng/ml, 0.5 ng/ml, and 0.1 ng/ml, respectively, and the linear range can meet the needs of clinical detection. Respectively, the recovery is 86.2%-93.8%, 100.9%-103.9% and 103.3%-107.1%; the total imprecision is 4.7%-7.4%, 3.5%-4.6% and 5.2%-10.9%. The measured values of Aβ 1-42 certified reference materials are all within the allowable uncertainty requirements. Moreover, the carryover rate of three analytes was all≤0.11%. In addition, the correlations of Aβ 1-42 and Aβ1-40 in CSF between this LC-MS/MS method and the INNOTEST ELISA method, Lumipulse G and Roche Elecsys fully automated biochemical analyzers were all deemed good, with correlation coefficient (r) ranging from 0.920 to 0.970. However, the measured values between the four methods were remarkably different.Conclusion:We established and validated a robust method based on LC-MS/MS technology for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in CSF. The method is accurate, simple, and suitable for clinical measurements. However, despite good correlations, there were substantial differences in the measurement results of Aβ 1-42 and Aβ 1-40 among different analytical platforms, indicating the need for further promotion of harmonization and standardization processes for AD classic biomarkers.
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Objective:The aim of our study is to develop an LC-MS/MS method using isotope internal standard for the determination of vancomycin in human blood serum and to validate its clinical value.Method:We conducted a methodological evaluation study using serum samples from 221 hospitalized patients (142 males and 79 females; mean age (59.31±15.32) years) who received treatments of vancomycin at the Sir Run Run Shaw Hospital of Zhejiang University between March 2021 and June 2022. In addition, thirty clinical residual serum samples from healthy individuals (15 males and 15 females; mean age (35.65±9.86) years) undergoing physical examination were used for methodological evaluation. The method was established using AB Sciex Triple Quad 4500 MD liquid chromatography-tandem mass spectrometer and chromatographic separation was carried out using a Phenyl-Hexyl column with gradient elution. The mobile phase was composed of 0.1% formic acid in water and methanol; the column temperature was 40℃; Vancomycin-[d12] TFA salt was used as the internal standard (IS). The sensitivity, specificity, linearity, accuracy, imprecision, matrix effect, and carry-over of the method were evaluated.Results:The detection limit of vancomycin was 0.2 mg/L and the lowest limit of quantification was 0.5 mg/L. It showed good linearity ( R2=0.998 4) in the 1 to 50 mg/L concentration range. Accuracy (recovery rate 87.45%-112.69%), intra-day and inter-day imprecision ( CV 4.91%-7.69%), internal standard standardized matrix factor (90.22%-104.29%). Carryover pollution was negligible. Of the 221 patients, the mean trough concentrations of vancomycin in serum was (13.15±8.56) mg/L. Conclusion:The LC-MS/MS method for the detection of serum vancomycin established in our laboratory meets the requirements of the reference method, and can be used for the monitoring of clinical therapeutic drugs.
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Objective:To establish the cut-off value of tetradecenoyl carnitine (C14∶1)/dodecenoyl carnitine(C12∶1) based on non-derivatized tandem mass spectrometry (MS/MS), and to explore the application value of C14∶1/C12∶1 to screen newborns for very long chain acyl-CoA dehydrogenase deficiency (VLCADD), determining the best combination of indicators for screening VLCADD.Methods:This retrospective study included data from 17 newborns with VLCADD detected by MS/MS and confirmed by acyl-CoA dehydrogenase very long chain ( ACADVL) gene detection, and 423 507 newborns with normal MS/MS results. The data from these newborns were collected from January 2014 to December 2021 as the newborns received neonatal screening in Nanjing Neonatal Disease Screening Center and Suzhou Neonatal Disease Screening Center. All newborns were divided into 3 groups: all newborns group, full-term newborns group and normal-birth-weight newborns group, and the cut-off values of C14∶1/C12∶1 for VLCADD in these 3 groups were determined by their receiver operating characteristic (ROC) curves individually. With these results, a total of 5 interpretation schemes were composed using different indicators alone or jointly: scheme 1 being C14∶1/C12∶1, scheme 2 being C14∶1, scheme 3 being C14∶1+C14∶1/C2+C14∶1/C16, scheme 4 being C14∶1/C12∶1+C14∶1, and scheme 5 being C14∶1/C12∶1+C14∶1+C14∶1/C2+C14∶1/C16. The detection rate, false-positive rate and positive predictive value of each scheme were calculated, and their screening efficiencies were statistically compared by Chi-square tests. Results:The cut-off values of C14∶1/C12∶1 for VLCADD in the 3 newborn groups were all 2.80. The detection rates of VLCADD with all 5 interpretation schemes were 17/17. Scheme 1 had the highest false positive rate [26.15‰ (11 075/423 524)] and the lowest positive predictive value [0.15% (17/11 092)]. Scheme 4 (Scheme 5) had the lowest false positive rate [0.02‰ (10/423 524)] and the highest positive predictive value [62.96% (17/27)]. Comparing scheme 4 (Scheme 5) with scheme 1, scheme 2 and scheme 3, the differences of false positive rate (χ2=302.30,11 191.50,32.06) and positive predictive value (χ2=102.51,3 485.61,13.83) were statistically significant (all P<0.001). Conclusion:C14∶1/C12∶1 was an effective auxiliary interpretive indicator for VLCADD in newborn screening, and the combination of C14∶1/C12∶1+C14∶1 was tested to be the best indicator for VLCADD screening based on non-derivatized tandem mass spectrometry.
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Objective:To investigate the accuracy, effectiveness and feasibility of MassARRAY genotyping assay in the diagnoses of neonatal genetic metabolic diseases.Methods:This is a retrospective study. From December 2016 to January 2020, newborns were screened by tandem mass spectrometry at the Zhejiang Newborn Screening Center, among which the data of 7 922 suspected positive cases of genetic metabolic diseases were collected. These patients were then tested for the common variants of 27 genetic metabolic diseases by MassARRAY genotyping assay, along with further testing using Sanger or next-generation sequencing used to verify and/or further search for potential variants.Results:A total of 1 408 cases were tested with MassARRAY. Among these, 307 cases were confirmed with certain genetic metabolic diseases. The detection rate of hyperphenylalaninemia was the highest, followed by primary carnitine deficiency, short acyl-coA dehydrogenase deficiency and methylmalonic acidemia. With these cases, the consistency of Sanger sequencing and MassARRAY was 100% (307/307). Another 287 cases were identified as carriers by MassARRAY with a 49.1% (141/287) consistency in reference to Sanger sequencing, mainly involving SLC22A5 and MCCC1 genes. Meanwhile, 50.8% (146/287) of these cases were found to have another variant mainly involving PAH, PTS and ACADS genes. The remaining 814 cases have no variants; 158 cases out of these patients have continuously abnormal amino acids, acyl carnitines, urine organic acid and/or other biochemical indices, and were tested by next-generation sequencing, among which 38% (60/158) were detected with two variants. In this study, a total of 513 patients with genetic metabolic disease were diagnosed, and the detection rate of MassARRAY was 59.8% (307/513). Conclusions:MassARRAY genotyping assay can be used as an early molecular screening method for neonatal genetic metabolic diseases. The detection rate is particularly high in diseases with a high concentration of hotspot variants, such as hyperphenylalaninemia and primary carnitine deficiency. The future application value of MassARRAY should be further improved by continuously optimizing its ability to identify new disease genes and potential variable sites.
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Objective@#To optimize the pretreatment method of N-nitrosamine compounds in ready-to-eat aquatic products. @*Methods@#Market-sold ready-to-eat aquatic products were collected, homogenized and distilled by steam. The samples were extracted for 10 minutes using dispersive liquid-liquid microextraction (DLLME) with ethanol, trichloromethane and sodium chloride (3.0 g). After centrifugation, the organic phase in the lower layer was collected and subjected to gas chromatography-tandem mass spectrometry (GC-MS/MS). The six common N-nitrosamine compounds were determined in ready-to-eat aquatic products using multiple reaction monitoring mode (MRM) and quantified by the internal standard method. @*Results@#The optimized method exhibited a good linear relationship at concentrations of 10.0 to 500 μg/L for determination of 6 N-nitrosamine compounds (correlation coefficient of greater than 0.999), with 0.05 to 0.60 μg/kg limit of detection, 0.15 to 1.60 μg/kg limit of quantitation, mean spiked recovery rates of 71.8% to 108.9%, and relative standard deviations of 1.4% to 8.6%. N-Nitrosodimethylamine showed the highest detection rate in 20 market-sold ready-to-eat aquatic products (90%), and the detection rates of N-Nitrosopyrrolidine, N-Nitrosodiethylamine and N-dibutylnitrosamine were 15%, 10% and 10%, respectively. @*Conclusion@#Steam distillation combined with DLLME may optimize the pretreatment method of N-nitrosamine compounds in ready-to-eat aquatic products and meet the measurement requirements.
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@#Abstract: Objective To investigate a poisoning incident caused by eating eight treasure congee, and establish liquid chromatography (LC)-mass spectrometry (MS)/MS screening method of 28 alkaloids to provide references for disposal of similar poisoning incidents. Methods LC-MS/MS was used for screening 28 alkaloids in the urine, eight treasure congee and food raw material, and the detected alkaloids were quantified. Samples were extracted with 0.4% formic acid aqueous solution and separated by a Acquity UPLC BEH C18 column (1.7 μm, 100 × 2.1 mm). Acetonitrile-0.2% formic acid aqueous solution was used as the mobile phase and gradient elution was adopted. The ionization mode was electrospray positive ionization mode, and the detection method was multi-reaction monitoring (MRM). Analytes were quantified with the external standard method. Results In the concentration range of 0-100 ng/mL, the linear correlation coefficient r were greater than 0.999 for 28 alkaloids. The recovery of 28 alkaloids in urine sample ranged from 63.0% to 105.0%, and the relative standard deviations (RSDs) were between 5.8% and 8.6%. The recovery of 28 alkaloids in eight treasure congee sample ranged from 72.0% to 109.0%, and the RSDs were between 6.3% and 9.7%. The recovery of 28 alkaloids in semen sesami nigrum sample ranged from 60.0% to 95.0%, and the RSDs were between 4.8% and 8.2%. Hyoscyamine (2 380.0 ng/mL), scopliamine (3.6 ng/mL) and rac-anisodamine (4.7 ng/mL) were detected in the patient's urine. Hyoscyamine (63.3 μg/g), scopliamine (5.7 μg/g) and rac-anisodamine (2.1 μg/g) were detected in eight treasure congee. Hyoscyamine (901.0 μg/g), scopliamine (80.0 μg/g) and rac-anisodamine (30.1 μg/g) were detected in the seed of Datura stramonium L. The ratio of scopliamine and hyoscyamine in the seed of D. stramonium was 1∶11, which complies with the characteristics of D. stramonium L. In urine sample, the proportion of scopliamine and rac-anisodamine was 0.15% and 0.20%, and hyoscyamine accounted for 99.65%. Conclusion Seed morphology, the content range and proportion of three alkaloids are all in accord with the characteristics of D. stramonium. Combined with the clinical symptoms of atropine poisoning, it can be deduced that this incident is a family food poisoning caused by accidental consumption of seed of D. stramonium L. The method can provide technical support for the clinical diagnosis and treatment of alkaloid poisoning patients, and also provide a basis for emergency detection and disposal of alkaloid poisoning events.
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Antibody-drug conjugate (ADC) has the characteristics of low toxicity and high efficiency, and plays an important role in cancer treatment. However, due to the complexity of its structure, it brings difficulties in pharmacokinetic (PK) bioanalysis. This study established an analytical method for the detection of ADC (RC108) in cynomolgus monkey plasma by ligand-binding assay (LBA) and liquid chromatography tandem mass spectrometry (LC-MS/MS), which was used to analyze and quantify the total antibody, bound antibody and free drug in cynomolgus monkey plasma. Based on the LBA method, rabbit anti-RC108 Fab and mouse anti-MMAE (monomethyl auristatin E) mAb were pre-coated in 96-well plates as the total antibody and antibody binding reagents, respectively. The samples to be tested were added, and then the detection reagents were added in turn. Goat anti-human IgG (H+L)-HRP, chromogenic solution tetramethylbenzidine (TMB), H2SO4 terminate the reaction, read data at 450 nm/630 nm wavelength of microplate reader; LC-MS/MS analysis method quantifies MMAE concentration, and refer to relevant regulations for methodological validation. The analytical method for quantifying total antibody, bound antibody and free drug of RC108 drug obtained good accuracy and precision, and the selectivity, dilution linearity, hook effect, parallelism and stability were verified. Meet the requirements of biological analysis. Finally, a bioanalytical method for the determination of the concentration of the test substance RC108 (total antibody, conjugated antibody, free MMAE) in cynomolgus monkey plasma with high sensitivity and high throughput was established by LBA and LC-MS/MS method. Subsequent non-clinical research on PK research in cynomolgus monkeys will provide technical support.
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A hydrophilic interaction chromatography tandem mass spectrometry method was developed for simultaneous quantification of 35 components in gualoupi injection. The analytes were separated with an ACQUITY XBridge Amide column using 20 mmol·L-1 ammonium formate aqueous solution (pH 3.0) as mobile phase A and 20 mmol·L-1 ammonium formate (pH 3.0)∶acetonitrile (1∶9) as mobile phase B for gradient elution. Mass spectrometry with dynamic multiple reaction monitoring and external standard method were used for quantitative analysis. A total of 35 components were determined in 10 batches of gualoupi injection. The results showed that the 35 compounds had a good linear relationship within their respective concentration ranges with the correlation coefficients (R2 > 0.998 0), the recoveries ranged from 76.6% to 118.5%. The results showed that γ-aminobutyric acid, trigonelline, alanine, threonine, homoserine, citrulline, and leucine were abundant in gualoupi injection, while nicotinamide, methylsuccinic acid, cytosine and choline account for a low percentege. The present study provides an important reference for elucidation of the effective material basis and the improvement of quality standard of gualoupi injection.
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ObjectiveTo investigate the mechanism of Renshen Guben oral liquids（RGOL） in treatment of mice with renal fibrosis based on metabolomics and network pharmacology. MethodC57BL/6 mice were randomly divided into control group， model group and RGOL group， 12 mice in each group. Except for the control group， mice in the other groups were induced into unilateral ureteral obstruction（UUO） model by UUO. After preparation of the model， an aqueous solution of 4.2 g·kg-1 extract powder was administered by gavage to RGOL group for 14 d， and an equal amount of distilled water was administered by gavage to the control and model groups. After the last administration on the 14th day， urine was collected and detected by ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry（UPLC-QQQ-MS/MS） with 0.1% formic acid aqueous solution as mobile phase A， and acetonitrile-isopropanol（70∶30） as mobile phase B for gradient elution（0-1 min， 5%B； 1-5 min， 5%-30%B； 5-9 min， 30%-50%B； 9-11 min， 50%-78%B； 11-13.5 min， 78%-95%B； 13.5-14 min， 95%-100%B； 14-16 min， 100%B； 16-16.1 min， 100%-5%B； 16.1-18 min， 5%B）， column temperature of 40 ℃， flow rate of 0.4 mL·min-1， electrospray ionization（ESI）， collection range of m/z 50-900. Through network pharmacology， the targets of components in RGOL and the targets of renal fibrosis were analyzed interactively， and the key components and key targets were screened by network topology analysis， and DAVID platform was used to predict the signaling pathways of RGOL for the treatment of renal fibrosis. ResultA total of 7 differential metabolites involving 8 metabolic pathways were identified in RGOL for the treatment of renal fibrosis. The network pharmacology revealed that 36 key components in RGOL were related to 7 differential metabolites， mainly ginsenosides， notoginsenosides and nucleotides. Based on the herbs-components-targets-pathways network， a total of 23 key targets related to the treatment of renal fibrosis by RGOL were highlighted， which together with the differential metabolites were involved in linoleic acid metabolism， arginine biosynthesis， tricarboxylic acid cycle（TCA）， arginine and proline metabolism and other pathways. ConclusionBased on metabolomics and network pharmacology， this study preliminarily identified 7 differential metabolites， 36 potential pharmacodynamic components and 23 key targets and 4 key pathways in RGOL for the treatment of renal fibrosis， providing an experimental basis for the clinical application and mechanism study of this preparation.
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ObjectiveTo perform a predictive analysis of the quality marker（Q-Marker） for the anticoagulant activity of Kunning granules. MethodThe chemical components of Kunning granules were analyzed by ultra high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry（UHPLC-Q-TOF-MS/MS） on a Waters ACQUITY UPLC HSS T3 column（2.1 mm×100 mm， 1.8 μm） with the mobile phase of acetonitrile（A）-25 mmol∙L-1 ammonium acetate aqueous solution（B） for gradient elution （0-5 min， 5%-22%A； 5-10 min， 22%-30%A； 10-15 min， 30%-95%A； 15-20 min， 95%-5%A； 20-30 min， 5%A）， flow rate of 0.2 mL∙min-1， column temperature at 30 ℃， injection volume of 1 μL， electrospray ionization（ESI）， positive and negative ion detection modes. Interaction analysis between the targets of chemical components and the targets of abnormal uterine bleeding（AUB） was performed by network pharmacology， and the key components were screened through network topology analysis. The fingerprints of 10 batches of Kunning granules were established by high performance liquid chromatography（HPLC）， the anticoagulant activity of the granules was determined by blood coagulation method and fibrinogen plate method， and the spectrum-effective relationship was established. The components co-occurring in the topological analysis and spectrum-effective relationship were selected as Q-Markers， and their anticoagulant activities were verified and confirmed. ResultA total of 475 chemical components were identified from Kunning Granule， of which 22 key components such as salvianolic acid B， paeoniflorin， naringin and neohesperidin， were the potential material basis for the treatment of AUB. The spectrum-effective analysis showed that peaks 7（paeoniflorin）， 9（naringin）， 10（neohesperidin） and 11（salvianolic acid B） were the optimal principal components， and in vitro activity test showed that these four components could better characterize their anticoagulant activity. ConclusionSalvianolic acid B， paeoniflorin， neohesperidin and naringin may be Q-Markers for the anticoagulant activity of Kunning granules.
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Objective@#To establish a ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry method for rapid simultaneous determination of quinclorac, acetochlor, butachlor and metolachlor in urine.@*Methods@#Urine samples were diluted 10 times, prepared into the mixed standard solution, and subjected to gradient elution on the ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase. The quinclorac, acetochlor, metolachlor and butachlor levels were determined using electrospray ionization-positive ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry with the multiple reaction monitoring mode.@*Results@#Four herbicides were effectively separated on the ACQUITY UPLC BEH C18 column (100 mm× 2.1 mm, 1.7 μm), and good linear relationships were observed for quinclorac, acetochlor and butachlor at 1 to 25 μg/L and for metolachlor at 0.2 to 25 μg/L, with all linear correlation coefficients of >0.999. The detection limts of quinclorac, acetochlor, butachlor and metolachlor were 0.10, 0.10, 0.20 and 0.01 μg/L, respectively. The recovery rates of quinclorac, acetochlor and butachlor were 107.42%, 93.94% and 90.27% from urine samples at a spiked level of 5 µg/L, with relative standard deviations of 4.82%, 3.84% and 6.76%, and the recovery rate of metolachlor was 89.51% at a spiked level of 0.5 µg/L, with a relative standard deviation of 8.98%.@*Conclusion@#The chromatography and mass spectrometry conditions are optimized in this ultra-high performance liquid chromatography-tandem mass spectrometry, which is effective for rapid simultaneous determination of quinclorac, acetochlor, metolachlor and butachlor in urine samples.
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Objective:To study disease spectrum and genetic profiles of inborn errors of metabolism (IEM) among newborns in selected areas of Nanning city.Methods:From July 2019 to December 2021, neonates born and received IEM screening in our hospital were prospectively enrolled. Heel blood samples were tested using tandem mass spectrometry as IEM screening. Neonates with positive results were called back for recheck. Whole exome sequencing was used to detect possible pathogenic genes in suspected cases and IEM was diagnosed combining clinical manifestations. Sanger sequencing method was used for the diagnosed neonates and their parents to confirm the diagnoses.Results:A total of 16 207 live-birth neonates were enrolled. For initial IEM screening, 1 423 neonates were positive (8.8%) and 1 311 were called back (92.1%). 15 cases were suspected with IEM and 8 were diagnosed. The overall detection rate was 1∶2 026. Among 8 confirmed cases, 4 cases had amino acid metabolism disorders (2 cases of phenylketonuria, 1 case of Citrin deficiency and 1 case of tyrosinemia), 2 cases had organic acid metabolism disorders (1 case of methylmalonic acidemia and 1 case of glutaric acidemia) and 2 cases had fatty acid oxidation disorders (1 case of carnitine palmitotransferaseⅡdeficiency and 1 case of primary carnitine deficiency). 5 cases had homozygous genetic variants (2 in PAH, and 1 in SLC25A13, SLC22A5 and FAH, respectively) and 3 had heterozygous genetic variants (1 in CPT2, MUT, and GCDH, respectively). During follow-up, all 8 cases had normal growth and developmental outcomes after standardized treatment.Conclusions:The overall detection rate of IEM is high, with varied genetic profiles in selected areas of Nanning. Timely genetic testing may lead to early diagnosis and treatment and improve the quality of life of neonates.