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Background Volatile organic compounds (VOCs) in exhaled breath are closely associated with respiratory diseases and are linked to various metabolic reactions in the human body. A quantitative analytical method can provide technical support for studying VOCs related to various diseases. Objective To establish a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method for the determination of 27 VOCs in exhaled breath. Methods VOCs in exhaled breath were collected using a Bio-VOC sampler and enriched with Tenax TA thermal desorption tubes before TD-GC-MS analysis. Standards were collected using thermal desorption tubes and optimized for thermal desorption conditions as well as chromatographic and mass spectrometric conditions: The separation of the 27 VOCs was achieved by an optimized temperature program, the improvement of sensitivity by optimizing quantitative ions, and the increase of VOCs desorption efficiency by optimizing thermal desorption time and temperature. Limit of detection, limit of quantification, accuracy, precision, and stability of the proposed method were investigated by spiking with a blank gas bag, and exhaled breath samples from 20 healthy individuals were collected for an application study of the proposed method. Results The thermal desorption temperature was 280 ℃, and desorption time was 6 min. A VF-624ms chromatographic column was selected for the separation of target substances. The initial temperature of heating program was 35 ℃, maintained for 1 min, and then increased to 100 ℃ at a heating rate of 3 ℃·min−1 for 1 min, followed by increasing to 210 ℃ at a heating rate of 28 ℃·min−1 for 5 min. A quantitative analysis was conducted with a single ion monitoring (SIM) mode. Under these conditions, the 27 VOCs showed good linear relationships in their respective concentration ranges and the correlation coefficients were higher than 0.9990. The limits of detection of the method were in the range of 0.01-0.13 nmol·mol−1, the limits of quantification were in the range of 0.02-0.44 nmol·mol−1, and the spiked recoveries were in the range of 80.1%-120.5%, with intra-batch and inter-batch precision ≤ 18.8% and 17.9% respectively. All substances can be stored at room temperature (23-28 °C) for 7 d and at 4 °C for 14 d. The proposed method was applied to exhaled breath samples from 20 subjects with detection rates≥ 80% (except for trans-2-pentene and decane) and a concentration range of 0.00-465.50 nmol·mol−1. Conclusion The established TD-GC-MS method for quantification of VOCs in exhaled breath is characterized by high sensitivity and good accuracy, and is suitable for quantitative determination of VOCs in exhaled breath, which can provide technical support for the study of exhaled breath VOCs.
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ObjectiveTo screen the differential markers by analyzing volatile components in Dalbergia odorifera and its counterfeits， in order to provide reference for authentication of D. odorifera. MethodThe volatile components in D. odorifera and its counterfeits were detected by headspace gas chromatography-mass spectrometry（HS-GC-MS）， and the GC conditions were heated by procedure（the initial temperature of the column was 50 ℃， the retention time was 1 min， and then the temperature was raised to 300 ℃ at 10 ℃ for 10 min）， the carrier gas was helium， and the flow rate was 1.0 mL·min-1， the split ratio was 10∶1， and the injection volume was 1 mL. The MS conditions used electron bombardment ionization（EI） with the scanning range of m/z 35-550. The compound species were identified by database matching， the relative content of each component was calculated by the peak area normalization method， and principal component analysis（PCA）， orthogonal partial least squares-discrimination analysis（OPLS-DA） and cluster analysis were performed on the detection results by SIMCA 14.1 software， and the differential components of D. odorifera and its counterfeits were screened out according to the variable importance in the projection（VIP） value>2 and P<0.05. ResultA total of 26， 17， 8， 22， 24 and 7 volatile components were identified from D. odorifera， D. bariensis， D. latifolia， D. benthamii， D. pinnata and D. cochinchinensis， respectively. Among them， there were 11 unique volatile components of D. odorifera， 6 unique volatile components of D. bariensis， 3 unique volatile components of D. latifolia， 6 unique volatile components of D. benthamii， 8 unique volatile components of D. pinnata， 4 unique volatile components of D. cochinchinensis. The PCA results showed that， except for D. latifolia and D. cochinchinensis， which could not be clearly distinguished， D. odorifera and other counterfeits could be distributed in a certain area， respectively. The OPLS-DA results showed that D. odorifera and its five counterfeits were clustered into one group each， indicating significant differences in volatile components between D. odorifera and its counterfeits. Finally， a total of 31 differential markers of volatile components between D. odoriferae and its counterfeits were screened. ConclusionHS-GC-MS combined with SIMCA 14.1 software can systematically elucidate the volatile differential components between D. odorifera and its counterfeits， which is suitable for rapid identification of them.
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The article is devoted to the study of lipids and fatty acid composition of the above-ground part of the Nepeta olgae Regel (L.) plant of the Laminaceae family. It was found that the content of neutral lipids (NL) is 5.54%, PL - 6.12%, and total lipids (NL, PL) - 11.66%. Of the neutral lipids, the unsaponifiable substances (HB) had a bright yellow color, which is explained by a small amount of carotenoids (88.87 mg%). Glycolipids dominate in PL. Among the unsaponifiable substances were found biologically active components such as hydrocarbons, carotenoids, aliphatic alcohols, sterols and triterpenols. Phytosterols were the main component of unsaponifiable NS. Quantitative and qualitative analysis of fatty acids from the plant Nepeta olgae Regel (L.) was carried out by gas chromatography (GC). 28 acids were identified, of which 11 compounds are saturated, and 7 compounds are unsaturated fatty acids. Of the fatty acids, the main ones are linolenic 18:3 (35.48), palmitic 16:0 (33.38%), as well as ?-3 polyunsaturated fatty acids, including eicosanoic 20:1, cis-11,14-eicosadienoic 20:2, 8,11,14-eicosatriene 20:3 + arachidonic 20:4. Extracts of Nepeta olgae Regel (L.) were distinguished by a high content of polyunsaturated acids, which determines their potential biological activity.
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Abstract This study determines the associations among serum lipid profiles, risk of cardiovascular disease, and persistent organic pollutants. Using Gas chromatography technique, the intensity of toxic pollutant residues in serum samples of Hypertensive patients were measured. Based on statistical analysis, the effects of different covariates namely pesticides, age, systolic blood pressure, diastolic blood pressure, and lipid profile duration was checked using the logistic regression model. Statistical computation was performed on SPSS 22.0. The P-values of F-Statistic for each lipid profile class are greater than 0.01 (1%), therefore we cannot reject the null hypothesis for all cases. The estimated coefficients, their standard errors, Wald Statistic, and odds ratio of the binary logistic regression model for different lipid profile parameters indicate if pesticides increase then the logit value of different lipid profile parameters changes from -0.46 to -0.246 except LDL which increases by 0.135. The study reports a significantly increased threat of cardiovascular disease with increased concentrations of toxic pollutants.
Resumo Este estudo determina as associações entre o perfil lipídico sérico, o risco de doença cardiovascular e os poluentes orgânicos persistentes. Por meio da técnica de cromatografia gasosa, mediu-se a intensidade dos resíduos de poluentes tóxicos em amostras de soro de pacientes hipertensos. Com base na análise estatística, os efeitos de diferentes covariáveis - ou seja, pesticidas, idade, pressão arterial sistólica, pressão arterial diastólica e duração do perfil lipídico - foram verificados usando o modelo de regressão logística. O cálculo estatístico foi realizado no SPSS 22.0. Os valores P da estatística F para cada classe de perfil lipídico são maiores que 0,01 (1%), portanto não podemos rejeitar a hipótese nula para todos os casos. Os coeficientes estimados, seus erros padrão, estatística de Wald e odds ratio do modelo de regressão logística binária para diferentes parâmetros do perfil lipídico indicam se os pesticidas aumentam, então o valor logit de diferentes parâmetros do perfil lipídico muda de -0,46 para -0,246, exceto LDL, que aumenta em 0,135. O estudo relata um aumento significativo da ameaça de doença cardiovascular com aumento das concentrações de poluentes tóxicos.
Subject(s)
Humans , Pesticides , Environmental Pollutants , Persistent Organic Pollutants , Lipids , LipoproteinsABSTRACT
ObjectiveTo analyze the fingerprint of six pungent herbs based on the molecular connectivity index（MCI）and the matching frequency total statistical moment method， and to study the division and integration of the "imprinting template" of their volatile components， so as to find the common "imprinting template" characteristics of the pungent herbs. MethodThe volatile components of six pungent herbs were extracted by steam distillation， and their fingerprints were established by gas chromatography-mass spectrometry（GC-MS） with a programmed temperature increase（80 ℃ for 5 min， 5 ℃·min-1 to 200 ℃ for 5 min， 2 ℃·min-1 to 230 ℃ for 10 min）， a splitting ratio of 20∶1， an electron bombardment ion source（EI） and the detection range of m/z 35-650， and the average MCI and total statistical moment parameters of the fingerprints were calculated. Then the matching frequency method was used to classify， integrate and confirm the chromatographic peaks of the fingerprints of six pungent herbs. ResultThe average zero order， first-order and second-order MCI values of the volatile components of Pogostemonis Herba， Artemisiae Argyi Folium， Atractylodis Rhizoma， Asari Radix et Rhizoma， Magnoliae Flos and Schizonepetae Herba were 9.02， 5.28 and 5.05， respectively. The average values of peak number， total zero-order moment， total first-order moment and total second-order moment were 60， 169×107， 22.49 min and 36.82 min2， respectively. The 20 integrated imprinting templates were obtained by the matching frequency method for the six pungent herbs， among which three were common imprinting templates with the retention times of （25.97±0.21），（26.90±0.20），（31.64±1.24） min， respectively， and the representative components were valencene，β-elemene， caryophyllin， etc. ConclusionMCI combined the matching frequency total statistical moment can divide and integrate the characteristics of imprinting templates of six pungent herbs， and find their common chromatographic imprinting characteristics， which can provide a reference for the determination of effective substances of pungent herbs.
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ObjectiveBy comparing the differences in composition and content of volatile components between Atractylodis Macrocephalae Rhizoma（AMR）and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， the effect of processing with rice-washed water on the volatile components in AMR and bran-fried AMR were investigated. MethodHeadspace gas chromatography-mass spectrometry（HS-GC-MS）was used to determine the volatile components in raw products， bran-fried products and their processed products with rice-washed water. GC conditions were programmed temperature（starting temperature of 50 ℃， rising to 140 ℃ at 10 ℃·min-1， maintained for 5 min， then rising to 210 ℃ at 4 ℃·min-1）， splitting ratio of 10∶1， high purity helium as the carrier gas and a solvent delay time of 3 min. MS conditions were an electron bombardment ion source（EI） with an electron collision energy of 70 eV， ion source temperature of 230 ℃， and the detection range of m/z 20-650. The relative contents of the components were determined by the peak area normalization method， the obtained sample data were subjected to principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） by SIMCA 14.1 software， and the differential components of AMR and bleaching AMR， and bran-fried AMR and bran-fried bleaching AMR were screened according to variable importance in the projection（VIP） value>1 and P<0.05. ResultA total of 71 volatile components were identified， including 53 in AMR， 50 in bleaching AMR， 51 in bran-fried AMR， and 44 in bran-fried bleaching AMR. OPLS-DA results showed that there were significant differences between AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， but not between AMR samples from different origins. The compound composition of AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR did not change， but the contents of monoterpenes and sesquiterpenes changed significantly. ConclusionSignificant changes in the contents of volatile components were observed in AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， among them， 1，2-dimethyl-4-methylidenecyclopentene， 9，10-dehydro-isolongifolene， γ-elemene， zingiberene， atractylone， silphinene， modhephene and （1S，4S，4aS）-1-isopropyl-4，7-dimethyl-1，2，3，4，4a，5-hexahydronaphthalene can be used as candidate differential markers of volatile components of AMR before and after processing with rice-washed water.
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OBJECTIVE To analyze the odor composition changes of two kinds of traditional Chinese medicine sachet （children type and adults type） with different placement time by using ultra-fast gasphase electronic nose technology. METHODS The change rule of sachet components at different storage times was analyzed by gas chromatography. At the same time， the qualitative results were obtained by combining electronic nose with Arochembase database. Discriminant factor analysis was used to analyze the overall odor composition differences of the two sachet samples. RESULTS A total of 10 odor compositions were identified in children-type sachet， including α-pinene and β-pinene as the functional index compositions； five odor compositions of children-type sachet disappeared after 0.25 days， and most of them disappeared after 7 days； the cumulative contribution rate of discriminant factor analysis was 99.225%. A total of 8 odor compositions were identified in adult-type sachets， including α-pinene and α-phellandrene as the functional index compositions； four odor components disappeared after the adult-type sachet was placed for 0.25 days； after 15 days of placement， the peak 6-8 disappeared， and the intensity of peak 5 decreased by 34.3% compared with 0 day of placement； the cumulative contribution rate of discriminant factor analysis was 91.965%. CONCLUSIONS With the extension of storage time， the smell and composition of the two traditional Chinese medicine sachets are decreasing. It is recommended that the use time of children-type sachet is 7 days， and that of adult-type sachet is 15 days.
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This study determines the associations among serum lipid profiles, risk of cardiovascular disease, and persistent organic pollutants. Using Gas chromatography technique, the intensity of toxic pollutant residues in serum samples of Hypertensive patients were measured. Based on statistical analysis, the effects of different covariates namely pesticides, age, systolic blood pressure, diastolic blood pressure, and lipid profile duration was checked using the logistic regression model. Statistical computation was performed on SPSS 22.0. The P-values of F-Statistic for each lipid profile class are greater than 0.01 (1%), therefore we cannot reject the null hypothesis for all cases. The estimated coefficients, their standard errors, Wald Statistic, and odds ratio of the binary logistic regression model for different lipid profile parameters indicate if pesticides increase then the logit value of different lipid profile parameters changes from -0.46 to -0.246 except LDL which increases by 0.135. The study reports a significantly increased threat of cardiovascular disease with increased concentrations of toxic pollutants.
Este estudo determina as associações entre o perfil lipídico sérico, o risco de doença cardiovascular e os poluentes orgânicos persistentes. Por meio da técnica de cromatografia gasosa, mediu-se a intensidade dos resíduos de poluentes tóxicos em amostras de soro de pacientes hipertensos. Com base na análise estatística, os efeitos de diferentes covariáveis ou seja, pesticidas, idade, pressão arterial sistólica, pressão arterial diastólica e duração do perfil lipídico foram verificados usando o modelo de regressão logística. O cálculo estatístico foi realizado no SPSS 22.0. Os valores P da estatística F para cada classe de perfil lipídico são maiores que 0,01 (1%), portanto não podemos rejeitar a hipótese nula para todos os casos. Os coeficientes estimados, seus erros padrão, estatística de Wald e odds ratio do modelo de regressão logística binária para diferentes parâmetros do perfil lipídico indicam se os pesticidas aumentam, então o valor logit de diferentes parâmetros do perfil lipídico muda de -0,46 para -0,246, exceto LDL, que aumenta em 0,135. O estudo relata um aumento significativo da ameaça de doença cardiovascular com aumento das concentrações de poluentes tóxicos.
Subject(s)
Male , Female , Humans , Adult , Cardiovascular Diseases/complications , Organic Pollutants , Chromatography, GasABSTRACT
Abstract This study determines the associations among serum lipid profiles, risk of cardiovascular disease, and persistent organic pollutants. Using Gas chromatography technique, the intensity of toxic pollutant residues in serum samples of Hypertensive patients were measured. Based on statistical analysis, the effects of different covariates namely pesticides, age, systolic blood pressure, diastolic blood pressure, and lipid profile duration was checked using the logistic regression model. Statistical computation was performed on SPSS 22.0. The P-values of F-Statistic for each lipid profile class are greater than 0.01 (1%), therefore we cannot reject the null hypothesis for all cases. The estimated coefficients, their standard errors, Wald Statistic, and odds ratio of the binary logistic regression model for different lipid profile parameters indicate if pesticides increase then the logit value of different lipid profile parameters changes from -0.46 to -0.246 except LDL which increases by 0.135. The study reports a significantly increased threat of cardiovascular disease with increased concentrations of toxic pollutants.
Resumo Este estudo determina as associações entre o perfil lipídico sérico, o risco de doença cardiovascular e os poluentes orgânicos persistentes. Por meio da técnica de cromatografia gasosa, mediu-se a intensidade dos resíduos de poluentes tóxicos em amostras de soro de pacientes hipertensos. Com base na análise estatística, os efeitos de diferentes covariáveis ou seja, pesticidas, idade, pressão arterial sistólica, pressão arterial diastólica e duração do perfil lipídico foram verificados usando o modelo de regressão logística. O cálculo estatístico foi realizado no SPSS 22.0. Os valores P da estatística F para cada classe de perfil lipídico são maiores que 0,01 (1%), portanto não podemos rejeitar a hipótese nula para todos os casos. Os coeficientes estimados, seus erros padrão, estatística de Wald e odds ratio do modelo de regressão logística binária para diferentes parâmetros do perfil lipídico indicam se os pesticidas aumentam, então o valor logit de diferentes parâmetros do perfil lipídico muda de -0,46 para -0,246, exceto LDL, que aumenta em 0,135. O estudo relata um aumento significativo da ameaça de doença cardiovascular com aumento das concentrações de poluentes tóxicos.
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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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ObjectiveBy exploring the volatile components， polysaccharide composition and changes in the contents of five carbohydrate components of Polygonatum cyrtonema rhizoma before and after processing， and then the effect of yellow rice wine on the odour formation of P. cyrtonema rhizoma was investigated. MethodThe volatile components of P. cyrtonema rhizoma before and after processing were detected by headspace gas chromatography-mass spectrometry（HS-GC-MS）， and sample data were subjected to principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） using SIMCA 14.1， then the differences between these components of P. cyrtonema rhizoma before and after processing were screened according to the principle of variable importance in the projection（VIP） value>1. Crude carbohydrate components in raw and wine-processed P. cyrtonema rhizoma were subjected to oxime and silylation， the carbohydrate components were analyzed by gas chromatography-mass spectrometry（GC-MS/MS）， and the relative contents of various components were calculated by peak area normalization， then quantitative analysis of four carbohydrate components was also carried out. ResultA total of 23 volatile components were identified from the raw products and the wine-processed products， including 15 components in raw products and 20 components in wine-processed products. Among them， 2-methylbutyraldehyde and isovaleraldehyde had a sweet odor and their contents increased after processing， but the contents of hexanal and caproic acid decreased， new components such as 2-acetylfuran and 5-methylfuranal were produced after processing. PCA and OPLS-DA results showed that there were significant differences between raw products and the wine-processed products， a total of 13 differential compounds were screened out， of which 7 showed an upward trend in relative content and 6 showed a downward trend. A total of 7 carbohydrate components， including 5 monosaccharides and 2 disaccharides， were identified in raw products and the wine-processed products. The results of determination showed that the contents of fructose， glucose， mannose and sucrose in P. cyrtonema rhizoma increased after wine-processing， and their increases were 4.54， 1.51， 2.93， 3.66 times， respectively. ConclusionAfter processing， the increase of aromatic flavor of P. cyrtonema rhizoma may be related to the increase of the contents of aldehydes such as 2-methylbutyraldehyde and isovaleraldehyde， while the decrease of raw flavor may be related to the decrease of the contents of volatile components such as hexanal and hexanoic acid， the increase of sweet flavor may be related to the increase of the contents of monosaccharides and oligosaccharides such as fructose and sucrose.
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ObjectiveTo investigate the key compounds affecting the irritation and to clarify the effect of heating and the addition of ginger juice as the auxiliary material during the processing on the irritation of Magnoliae Officinalis Cortex（MOC） by comparing the irritation and composition of volatile oil in MOC and its different processed products. MethodVolatile oil in raw products， water-processed products， ginger-dried products， ginger-fried products（the amounts of ginger were 10%， 50%， respectively） of MOC were extracted by steam distillation and subjected to rabbit eye irritation experiment， and the volatile components of each sample were detected by gas chromatography-mass spectrometry（GC-MS）. Principal component analysis（PCA）and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to analyze the data of each sample by SIMCA 14.1. The relative contents of different processed products were compared two by two with those of and raw products or ginger-fried products， and the markers that might be related to the irritation were sorted out according to the principles of variable importance in the projection（VIP） value >1 and P<0.05， and the factors influencing the differences in irritation were analyzed. ResultCompared with the blank group， the administration groups all had irritation to the eyes of rabbits， and the degree of irritation was in the order of raw products>water-processed products>ginger-dried products>ginger-fried products（10%）>ginger-fried products（50%）. The results of PCA and OPLS-DA showed that there were differences in the volatile oil from raw products and different processed products. According to VIP value>1 and P<0.05， and combined with the results of eye irritation experiment， ten volatile compounds related to irritation changes were screened out. Among them， cis-cinnamaldehyde was only detected in raw products， the relative contents of β-caryophyllene， （+）-delta-cadinene， α-humulene， γ-muurolene， （-）-isoledene and citral all increased to different degrees， the contents of p-cymene， 1（10）-4-cadinadien-15-ol and β-eudesmol all decreased to different degrees. ConclusionThe irritation of MOC is reduced after heating and processing with ginger juice， and the synergistic effect of both is more effective for reducing irritation. Among the differential markers associated with changes in irritation， the increase in the relative content of citral is closely related to the addition of ginger juice， while the decrease in the relative contents of cis-cinnamaldehyde， p-cymene， 1（10）-4-cadinadien-15-ol is related to heating， and the changes of other components may be related to the synergistic effect of heating and ginger juice.
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ObjectiveTo study the differences in volatile oil content of bran-processed Atractylodes lancea and its standard decoction concentrate and freeze-dried powder， as well as the differences in the types and contents of chemical components in volatile oil， and to clarify the quality value transmitting. MethodTen batches of A. lancea rhizoma were collected and prepared into raw products and bran-processed products of A. lancea， standard decoction concentrate and freeze-dried powder of bran-processed A. lancea in order to extract the volatile oil， and the transfer rate of volatile oil in each sample was calculated. Quantitative analysis of the main chemical components（β-eudesmol， atractylon， atractylodin） in each volatile oil was performed by gas chromatography（GC） on the HP-5 quartz capillary column（0.32 mm×30 m， 0.25 μm） with a flame ionization detector（FID）， a split ratio of 10∶1 and a temperature program（initial temperature at 80 ℃， hold for 1 min， rise to 150 ℃ at 10 ℃·min-1， hold for 10 min， rise to 155 ℃ at 0.5 ℃·min-1， hold for 5 min， rise to 240 ℃ at 8.5 ℃·min-1， hold for 8 min）. Cluster analysis and principal component analysis（PCA） were used to explore the overall differences in types and contents of chemical components between the standard decoction concentrate and freeze-dried powder. ResultThe transfer rates of volatile oil in the bran-processed products， standard decoction concentrate and freeze-dried powder were 70.51%， 1.57% and 40.90%， respectively. The average transfer rates of β-eudesmol， atractylon and atractylodin in the volatile oil of bran-processed A. lancea were 58.45%， 48.49% and 55.64%， respectively. In the standard decoction concentrate， only β-eudesmol and atractylodin were detected， and their average transfer rates were 0.22% and 0.10%， respectively. And only β-eudesmol was detected in the freeze-dried powder with the average transfer rate of 8.37%. The results of cluster analysis and PCA showed that there are obvious differences in the types and contents of chemical components between the standard decoction concentrate and freeze-dried powder. ConclusionThe quality value transmitting between bran-processed A. lancea and its standard decoction concentrate and freeze-dried powder is stable， and if the freeze-dried powder is selected as the reference material of dispensing granules， appropriate amount of volatile oil should be added back to make it consistent with the quality of the standard decoction concentrate.
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Objective To establish a rapid qualitative analysis method for volatile organic components in chemicals. Methods Headspace gas chromatography-mass spectrometry was used to qualitatively determine 19 volatile organic components, including benzene, 1,2-dichloroethane, and n-hexane, in chemicals. Different sample amounts, heating temperatures, heating times, and sample volumes were analyzed to assess their effects on detection results and optimize sampling conditions. Results Based on the set chromatography, the optimal sampling process of this method was as follows： 5.0 g sample in a 20.0 mL headspace bottle, incubated at 40 ℃ for 30 minutes in a constant-temperature drying incubator, and a 1.00 mL headspace gas injection. The within-run and between-run relative standard deviations of all components ranged from 0.00% to 21.05% and 0.00% to 33.33%, respectively. The samples stored in sealed glass containers were stable at room temperature for at least 60 days. Conclusion This method offers simplicity, good reproducibility, and stability, making it suitable for rapid qualitative analysis of volatile organic components in chemicals.
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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 explore the application of Quality by Design (QbD) tools in assessing geographical variations of Phyllanthus emblica (P. emblica) from five distinct Indian states. [Methods] In the current experiment, the Box-Behnken design with a reduced quartic model and 105 runs was employed with the use of the Design Expert software for randomized response surface mapping. Three different extraction methods (Soxhlet, maceration, and sonication) along with three solventst [distilled water, methanol, and water-methanol mixture (50 : 50 v/v)] were considered in the present study. The anti-oxidant activities, total flavonoid content (TFC), and total phenolic content (TPC) in the P. emblica were determined and analysed by gas chromatography-mass spectrometry (GC-MS) to identify the major components. [Results] The QbD overlay plot showed that the extractive value of the P. emblica was no less than 30% w/w, 2,2-diphenyl-1-picrylhydrazyl (DPPH) no less than 60% mcg/mL (micrograms per millilitre), TFC no less than 75 mg QE/g (milligrams of quercetin equivalents per gram), and TPC no less than 80 mg GAE/g (milligrams of gallic acid equivalents per gram). Moreover, the GC-MS data confirmed the presence of variation in the bioactives of P. emblica extracts. [Conclusion] The model was significant in describing the variation in extractive value, DPPH, TFC, and TPC. The QbD approach may tend to prioritize thoroughness in the extraction process, ultimately resulting in improved quality in the extracted products.
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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: To establish a solvent desorption-gas chromatography method for the determination of 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane in workplace air. Methods: The 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane in workplace air were collected using activated carbon tubes, desorbed with carbon disulfide, and separated and detected by gas chromatography. The quantifications were based on standard curves. Results: The linear ranges of 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane were 0.98-395.50 and 0.87-395.50 mg/L, respectively, with the correlation coefficient of 0.999 95. The detection limits were 0.29 and 0.26 mg/L, respectively. The average of desorption efficiency was 92.04%-104.67%. The within- and between-run relative standard deviations were 1.42%-2.09% and 1.63%-6.09%, respectively. The sampling efficiency was more than 98.00%. The samples could be stored at room temperature for at least 14 days. Conclusion: This method can be used in detection of 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane in workplace air.
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Objective: To establish a solvent desorption-gas chromatography method for determination of dimethyl carbonate (DMC) in workplace air. Methods: The air samples were collected using activated carbon tubes, desorbed by carbon disulfide, separated by dimethylpolysiloxane capillary columns, and detected by a flame ionization detector. Results: The linear range of DMC was 2.14 to 1.07×104 mg/L, and the correlation coefficient was greater than 0.999. The detection limit was 0.14 mg/L, the lower limit of quantification was 0.47 mg/L, the minimum detection concentration was 0.10 mg/m3, and the minimum quantification concentration was 0.32 mg/m3 (based on 1.5 L workplace air). The average desorption efficiency of the method was 96.2% to 102.0%. Both the within-run and between-run relative standard deviations were 0.9% to 2.3%. The samples could be stored for at least seven days at four celsius degree. Conclusion: This method shows high desorption efficiency, high sensitivity, good precision and is simple in using. It can be used for the determination of DMC in workplace air.
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Polycyclic aromatic hydrocarbons, PAHs are carcinogenic and genotoxic in nature and have been of worldwide concern. This study aimed at determining the PAH contamination levels in types of wheat (Tritcum specie), bambara groundnut (Vigna subterranea) and pigeon peas (Cajanus cajanifolia) commonly consumed in the eastern part of Nigeria and assess the health risk associated with their consumption. The grain samples were analyzed of sixteen priority PAHs using gas chromatography coupled with flame ionization detector, GC-FID after extraction by sonication. Estimation of daily intakes were carried out using adult male and female consumers while margin of exposure was used to assess the health risk applying bench mark dose levels for the indicators-BaP, PAH2, PAH4 and PAH8. The sixteen PAHs were detected in all the analyzed grains. The ∑16 PAHs concentrations (× 10¯²µg/kg) detected ranged from 25.004±20.553 in white pigeon peas to 36.493±20.305 in red pigeon peas. The eight probable carcinogenic PAHs (∑PAH8) detected ranged from 10.913±4.295 to 17.444±7.023 also in white and red pigeon peas respectively. From the estimation of daily intake calculated, the total dietary exposure of male (41.42 µg/kg bw/day) was less than that of female (48.24 µg/kg bw/day) implying that adult female are more exposed. The MOE for adult male individual ranged from 49,893 in pure white bambara groundnut to 392,943 in pigeon peas. While for adult female individual, the values of MOE ranged from 48,110 in bambara groundnut to 336,770 in pigeon peas. The values of margin of MOE obtained for all the indicators were much higher than 10000 which according to EFSA indicate low concern for human health and considered low priority for risk management actions. The PAHs values detected were all below 1.0 µg/kg which is the permissible limit established by EFSA. Based on these facts, these grains are safe for consumption.