Age Discrimination Based on Volatile Components of Arisaema Cum Bile / 中国实验方剂学杂志

ObjectiveTo discriminate the age of Arisaema Cum Bile， the combination of headspace solid-phase microextraction （HS-SPME） with gas chromatography-mass spectrometry （GC-MS） was applied to explore the differences of volatile components of unfermented， 1-year fermented， 2-year fermented， and 3-year fermented Arisaema Cum Bile. MethodSamples with different fermentation durations were collected and HS-SPME-GC-MS technology was employed to detect the volatile components of each sample. The relative contents of detected volatile components were processed and analyzed by chemometrics methods such as principal component analysis （PCA）， hierarchical cluster analysis （HCA）， and partial least squares discriminant analysis （PLS-DA）. ResultThe results showed that 145 volatile components were identified. Among these volatile components， the relative contents of heterocyclic， alcohols， aldehydes and aromatics were high. PCA， HCA， and PLS-DA can effectively separate Arisaema Cum Bile with four different ages. Based on variable importance in projection （VIP） value > 1， 73 markers of differential volatile components were identified. The content of 2，6，11-trimethyldodecane and m-xylene in unfermented samples was the highest， and the content difference between them and those in fermented samples was significant （P<0.05）. 2，3-butanediol was detected only in 1-year samples， octane was detected only in 2-year samples， and ethyl heptanoate was detected only in 3-year samples. These components can be used as odor markers for Arisaema Cum Bile with different fermentation years. ConclusionThe identification method of volatile components of Arisaema Cum Bile was established by HS-SPME-GC-MS technology， which can realize the rapid identification of unfermented， 1-year fermented， 2-year fermented， and 3-year fermented samples， and provide a scientific basis for the standardization of processing technology and quality standards of Arisaema Cum Bile.

Optimization of pretreatment methods for N-nitrosamine compounds in ready-to-eat aquatic products / 预防医学

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.

Comparison of different approaches for direct coupling of solid-phase microextraction to mass spectrometry for drugs of abuse analysis in plasma / 药物分析学报

The direct coupling of solid-phase microextraction(SPME)to mass spectrometry(MS)(SPME-MS)has proven to be an effective method for the fast screening and quantitative analysis of compounds in complex matrices such as blood and plasma.In recent years,our lab has developed three novel SPME-MS techniques:SPME-microfluidic open interface-MS(SPME-MOI-MS),coated blade spray-MS(CBS-MS),and SPME-probe electrospray ionization-MS(SPME-PESI-MS).The fast and high-throughput nature of these SPME-MS technologies makes them attractive options for point-of-care analysis and anti-doping testing.However,all these three techniques utilize different SPME geometries and were tested with different MS instruments.Lack of comparative data makes it difficult to determine which of these methodologies is the best option for any given application.This work fills this gap by making a comprehensive comparison of these three technologies with different SPME devices including SPME fibers,CBS blades,and SPME-PESI probes and SPME-liquid chromatography-MS(SPME-LC-MS)for the analysis of drugs of abuse using the same MS instrument.Furthermore,for the first time,we developed different desorption chambers for MOI-MS for coupling with SPME fibers,CBS blades,and SPME-PESI probes,thus illustrating the universality of this approach.In total,eight analytical methods were developed,with the experimental data showing that all the SPME-based methods provided good analytical performance with R2 of linearities larger than 0.9925,accuracies between 81％and 118％,and good precision with an RSD％≤13％.

Solid-phase microextraction of endogenous metabolites from intact tissue validated using a Biocrates standard reference method kit / 药物分析学报

Improved analytical methods for the metabolomic profiling of tissue samples are constantly needed.Currently,conventional sample preparation methods often involve tissue biopsy and/or homogenization,which disrupts the endogenous metabolome.In this study,solid-phase microextraction(SPME)fibers were used to monitor changes in endogenous compounds in homogenized and intact ovine lung tissue.Following SPME,a Biocrates AbsoluteIDQ assay was applied to make a downstream targeted metab-olomics analysis and confirm the advantages of in vivo SPME metabolomics.The AbsoluteIDQ kit enabled the targeted analysis of over 100 metabolites via solid-liquid extraction and SPME.Statistical analysis revealed significant differences between conventional liquid extractions from homogenized tissue and SPME results for both homogenized and intact tissue samples.In addition,principal component analysis revealed separated clustering among all the three sample groups,indicating changes in the metabolome due to tissue homogenization and the chosen sample preparation method.Furthermore,clear differences in free metabolites were observed when extractions were performed on the intact and homogenized tissue using identical SPME procedures.Specifically,a direct comparison showed that 47 statistically distinct metabolites were detected between the homogenized and intact lung tissue samples(P＜0.05)using mixed-mode SPME fibers.These changes were probably due to the disruptive homogenization of the tissue.This study's findings highlight both the importance of sample preparation in tissue-based metabolomics studies and SPME's unique ability to perform minimally invasive extractions without tissue biopsy or homogenization while providing broad metabolite coverage.

Advances in liquid-phase microextraction technology and its application in biological sample pretreatment / 药学学报

Liquid-phase microextraction is a novel pretreatment technique for biological samples developed on the basis of liquid-phase extraction technology, which is simple, rapid, economical, and environmentally friendly, and has been widely used in the analysis of biological matrix samples such as blood, urine, and saliva. In this paper, we review the basic principles of the main modes of liquid-phase microextraction techniques, i.e., single-drop microextraction, dispersive liquid-liquid microextraction, and hollow-fiber liquid-phase microextraction, and the progress of their applications in biological sample pretreatment by reviewing the literature in the past five years, with a view to providing technical support and reference for sample pretreatment in the fields of in vivo drug analysis, pharmacokinetic studies and new drug development.

Metabolomic fingerprinting of porcine lung tissue during pre-clinical prolonged ex vivo lung perfusion using in vivo SPME coupled with LC-HRMS / 药物分析学报

Normothermic ex vivo lung perfusion(NEVLP)has emerged as a modernized organ preservation tech-nique that allows for detailed assessment of donor lung function prior to transplantation.The main goal of this study was to identify potential biomarkers of lung function and/or injury during a prolonged(19 h)NEVLP procedure using in vivo solid-phase microextraction(SPME)technology followed by liquid chromatography-high resolution mass spectrometry(LC-HRMS).The use of minimally invasive in vivo SPME fibers for repeated sampling of biological tissue permits the monitoring and evaluation of biochemical changes and alterations in the metabolomic profile of the lung.These in vivo SPME fibers were directly introduced into the lung and were also used to extract metabolites(on-site SPME)from fresh perfusate samples collected alongside lung samplings.A subsequent goal of the study was to assess the feasibility of SPME as an in vivo method in metabolomics studies,in comparison to the traditional in-lab metabolomics workflow.Several upregulated biochemical pathways involved in pro-and anti-inflammatory responses,as well as lipid metabolism,were observed during extended lung perfusion,especially between the 11th and 12th hours of the procedure,in both lung and perfusate samples.However,several unstable and/or short-lived metabolites,such as neuroprostanes,have been extracted from lung tissue in vivo using SPME fibers.On-site monitoring of the metabolomic profiles of both lung tissues through in vivo SPME and perfusate samples on site throughout the prolonged NEVLP procedure can be effectively performed using in vivo SPME technology.

Covalent organic nanospheres as a fiber coating for solid-phase microextraction of genotoxic impurities followed by analysis using GC-MS / 药物分析学报

Covalent organic nanospheres(CONs)were explored as a fiber coating for solid-phase microextraction of genotoxic impurities(GTIs)from active ingredients(AIs).CONs were synthesized by an easy solution-phase procedure at 25℃.The obtained nanospheres exhibited a high specific surface area,good ther-mostability,high acid and alkali resistance,and favorable crystallinity and porosity.Two types of GTIs,alkyl halides(1-iodooctane,1-chlorobenzene,1-bromododecane,1,2-dichlorobenzene,1-bromooctane,1-chlorohexane,and 1,8-dibromooctane)and sulfonate esters(methyl p-toluenesulfonate and ethyl p-toluenesulfonate),were chosen as target molecules for assessing the performance of the coating.The prepared coating achieved high enhancement factors(5097-9799)for the selected GTIs.The strong affinity between CONs and GTIs was tentatively attributed to T-T and hydrophobicity interactions,large surface area of the CONs,and size-matching of the materials.Combined with gas chromatography-mass spectrometry(GC-MS),the established analytical method detected the GTIs in capecitabine and imatinib mesylate samples over a wide linear range(0.2-200 ng/g)with a low detection limit(0.04-2.0 ng/g),satisfactory recovery(80.03％-109.5％),and high repeatability(6.20％-14.8％)and reproducibility(6.20％-14.1％).Therefore,the CON-coated fibers are promising alternatives for the sensitive detection of GTIs in AI samples.

Current developments of bioanalytical sample preparation techniques in pharmaceuticals / 药物分析学报

Sample preparation is considered as the bottleneck step in bioanalysis because each biological matrix has its own unique challenges and complexity.Competent sample preparation to extract the desired analytes and remove redundant components is a crucial step in each bioanalytical approach.The matrix effect is a key hurdle in bioanalytical sample preparation,which has gained extensive consideration.Novel sample preparation techniques have advantages over classical techniques in terms of accuracy,automation,ease of sample preparation,storage,and shipment and have become increasingly popular over the past decade.Our objective is to provide a broad outline of current developments in various bioanalytical sample preparation techniques in chromatographic and spectroscopic examinations.In addition,how these techniques have gained considerable attention over the past decade in bioanalytical research is mentioned with preferred examples.Modern trends in bioanalytical sample preparation techniques,including sorbent-based microextraction techniques,are primarily emphasized.

Modifying current thin-film microextraction(TFME)solutions for analyzing prohibited substances:Evaluating new coatings using liquid chromatography / 药物分析学报

For identifying and quantifying prohibited substances,solid-phase microextraction(SPME)continues to arouse interest as a sample preparation method.However,the practical implementation of this method in routine laboratory testing is currently hindered by the limited number of coatings compatible with the ubiquitous high-performance liquid chromatography(HPLC)systems.Only octadecyl(C18)and poly-dimethylsiloxane/divinylbenzene ligands are currently marketed for this purpose.To address this situ-ation,the present study evaluated 12 HPLC-compatible coatings,including several chemistries not currently used in this application.The stationary phases of SPME devices in the geometry of thin film-coated blades were prepared by applying silica particles bonded with various functional ligands(C18,octyl,phenyl-hexyl,3-cyanopropyl,benzenesulfonic acid,and selected combinations of these),as well as unbonded silica,to a metal support.Most of these chemistries have not been previously used as microextraction coatings.The 48 most commonly misused substances were selected to assess the extraction efficacy of each coating,and eight desorption solvent compositions were used to optimize the desorption conditions.All samples were analyzed using an HPLC system coupled with triple quadrupole tandem mass spectrometry.This evaluation enables selection of the best-performing coatings for quantifying prohibited substances and investigates the relationship between extraction efficacy and the physicochemical characteristics of the analytes.Ultimately,using the most suitable coatings is essential for trace-level analysis of chemically diverse prohibited substances.

Analysis of Quality Changes of Platycladi Semen Before and After Deterioration Based on HS-SPME/GC-MS and Electronic Sensory Technology / 中国实验方剂学杂志

ObjectiveTo analyze the quality changes of Platycladi Semen before and after the deterioration of moth-eaten and rancidity during storage. MethodFour types samples of Platycladi Semen， including normal， moth-eaten， oxidative rancidity and hydrolytic rancidity， were determined for volatile components， odor， and taste based on headspace solid phase microextraction/gas chromatography-mass spectrometry （HS-SPME/GC-MS） and electronic sensory techniques such as electronic nose and electronic tongue. Volatile components were identified by searching the database and manual comparison， the odor and taste were determined by the response values of the electronic nose and electronic tongue sensors， and the difference between samples before and after deterioration was studied by multivariate statistical analysis. ResultA total of 85 compounds were identified in Platycladi Semen samples. Compared with the normal samples， the number of volatile compounds in samples after hydrolytic rancidity decreased by 5， the number of volatile compounds in samples after moth-eaten and oxidative rancidity increased by 1 and 21， respectively. Aldehydes and acids accounted for majority of types. Among them， the contents of N-hexanoic acid， hexanal and propionic acid in the samples of oxidative rancidity reached 11.49%， 10.21% and 7.52%， which became the key indicators of rancidity. There was significant variance among the odor components corresponding to W1W， W2W and W1S sensors by electronic nose analysis. It was indicated that the value of sourness in deteriorated samples generally increased by mean of electronic tongue analysis. Compared with normal samples， the moth-eaten samples had changed slightly and rancidity samples had changed significantly especially oxidative rancidity samples of volatile components， odor and taste by multivariate statistical analysis. ConclusionIn terms of Platycladi Semen， the oxidative rancidity caused by nature storage for 12 months has the greatest impact on the quality. Therefore， it should be mainly to prevent oxidative rancidity to ensure the quality of Platycladi Semen.

Comparison on Changes of Volatile Components in Gecko Before and After Processing by HS-SPME-GC-MS / 中国实验方剂学杂志

ObjectiveOn the basis of sensory evaluation， the changes of volatile components in gecko before and after processing were compared， and the odor correction effect of different processing methods of gecko was discussed. MethodRaw products， fried yellow products， vinegar processed products， wine processed products， talcum powder scalding products and white wine sprayed products after scalding talcum powder of gecko were prepared， and 10 odor assessors were invited to evaluate the 6 samples in turn by sensory evaluation. Headspace solid-phase microextraction-gas chromatography-mass spectrometry （HS-SPME-GC-MS） and relative odor activity value （ROAV） were used to analyze the key odor components， and multivariate statistical methods were used to analyze the difference of volatile components between raw and processed products of gecko. Taking water-soluble extract and protein contents as internal indicators， sensory evaluation score and content ranking of differential components as external indicators， and assigning a weight of 0.25 to them respectively， the comprehensive scores of raw products and processed products of gecko were calculated to evaluate the odor correction effect of each processing method. ResultThe average sensory evaluation scores of the raw products， fried yellow products， vinegar processed products， wine processed products， talcum powder scalding products and white wine sprayed products after scalding talcum powder of gecko were 1.6， 5.2， 6.2， 6.1， 7.2 and 8.0， respectively. ROAV results showed that key components affecting odor of gecko were 2-ethyl-3，5-dimethylpyrazine， isovaleraldehyde， trimethylamine， 1-octen-3-ol， n-octanal， nonanal， 2-methylnaphthalene， γ-octanolide， 2-heptanone and phenol. Principal component analysis （PCA） significantly distinguished raw products from processed products. Orthogonal partial least squares-discriminant analysis （OPLS-DA） results showed that there were 16， 13， 16， 16， 16 differential components between raw products， fried yellow products， vinegar processed products， wine processed products， talcum powder scalding products and white wine sprayed products after scalding talcum powder of gecko. Among these differential components， there were 4 common components， namely， the contents of different odor components （2-methylnaphthalene and 2-ethyl-p-xylene） decreased， while the contents of different flavor components （2-decanone and 2，3，5-trimethylpyrazine） increased. The comprehensive scoring results showed that the odor correction effect of each processed products was in the order of talcum powder scalding products>wine processed products>vinegar processed products>fried yellow products>white wine sprayed products after scalding talcum powder. ConclusionTalcum powder scalding is a better method to improve the odor of gecko， and it can provide an experimental basis for the processing of gecko to correct the odor.

Time-course monitoring of in vitro biotransformation reaction via solid-phase microextraction-ambient mass spectrometry approaches / 药物分析学报

The solid-phase microextraction technique quantifies analytes without considerably affecting the sample composition.Herein,a proof-of-concept study was conducted to demonstrate the use of coated probe electrospray ionization(coated-PESI)and coated blade spray(CBS)as ambient mass spectrometry ap-proaches for monitoring drug biotransformation.The ability of these methods was investigated for monitoring the dephosphorylation of a prodrug,combretastatin A4 phosphate(CA4P),into its active form,combretastatin A4(CA4),in a cell culture medium supplemented with fetal bovine serum.The CBS spot analysis was modified to achieve the same extraction efficiency as protein precipitation and ob-tained results in 7 min.Because coated-PESI performs extraction without consuming any samples,it is the preferred technique in the case of a limited sample volume.Although coated-PESI only extracts small quantities of analytes,it uses the desorption solvent volume of 5-10 pL,resulting in high sensitivity,thus allowing the detection of compounds after only 1 min of extraction.The biotransformation of CA4P into CA4 via phosphatases occurs within the simple matrix,and the proposed sample preparation techniques are suitable for monitoring the biotransformation.

Desirability Function in analytical method development for determination of glitazones and metabolites employing HF-LPME

Abstract Thiazolidinedione, often shortened to TZD or glitazone, helps lower insulin resistance, which is the underlying problem for many people with type 2 diabetes. The two most known glitazones are pioglitazone (PGZ), with the brand name medicine Actos®, and rosiglitazone (RSG), which is Avandia®. This study presented a multivariate optimization in the microextraction procedure employing Fractional Factorial Design (FFD) combined with Desirability Function (DF) to determine TZD and metabolites in biological samples. Microextraction requires several parameters to be optimized; however, most of them still use univariate optimization. Finding optimum conditions by simple response is relatively simple, but the problems, in case of microextractions, are often more complex when it has more responses. For example, changing one factor that promotes one response may suppress the effect of the others. Thus, this multivariate optimization was applied for two bioanalytical methods for determination of TZD and metabolites, one by HPLC and other by CE, both using Hollow Fiber Liquid-Phase Microextraction (HF-LPME). The results establish the optimal values and elucidate how the factors that affect HF-LPME procedure perform in extraction efficiency for TZDs. Additionally, this study demonstrates that DF can be an important tool to optimize microextraction procedures.

Molecular Mechanism of Selective Binding of Pharmacodynamic Active BVOCs Substance Group with Bovine β-Lactoglobulin / 中国生物化学与分子生物学报

Headspace-solid phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) were used to analyze the interaction between the β-lactoglobulin (β-LG) and the botany volatile organic compounds (BVOCs) from pomelo peel to screen out the pharmacodynamic active BVOCs substance group. The selective binding effect between β-LG and BVOCs was analyzed by quantitative recovery of BVOCs, and the binding parameters were calculated. Then, the molecular model of BVOCs binding with β-LG was established by molecular docking and spectroscopic method, and the molecular mechanism of interaction between pharmacodynamic active BVOCs and β-LG was discussed from the perspective of omics. The results showed that dipentene (Dt), linalylacetate (La) and nootkatone (Nt) of BVOCs were selected by HS-SPME/GC-MS by the interaction of β-LG and BVOCs substance group. Parameter calculation showed that β-LG had the strongest affinity with Nt, but the binding force was not strong, and the affinity for La was the weakest. The affinity of β-LG to Dt was weak, but the binding force was the strongest, with a binding rate of 54. 66%, indicating that the selective binding strength of β-LG with the pharmacodynamic active BVOCs depended on the chemical structure of BVOCs molecules. The β-LG preferred to bind to the aldehyde and ketone BVOCs molecules containing carbonyl oxygen structure. The molecular model of β-LG and BVOCs group (Dt, La, Nt) was established to evaluate the binding position of BVOCs group (Dt, La, Nt) on β-LG. The loosening, extension and conformational change of β-LG secondary structure caused by the introduction of BVOCs are the result of van der Waals force, hydro-phobicity and hydrogen bonding. This study provides a new method for screening pharmacodynamic active BVOCs from the perspective of whole substance group of BVOCs, and provides a useful reference for investigating the binding mechanism between pharmacodynamic active BVOCs and functional protein molecules from the perspective of omics.

One extraction tool for in vitro-in vivo extrapolation?SPME-based metabolomics of in vitro 2D,3D,and in vivo mouse melanoma models / 药物分析学报

Solid phase microextraction(SPME)in combination with high-resolution mass spectrometry was employed for the determination of metabolomic profile of mouse melanoma growth within in vitro 2D,in vitro 3D,and in vivo models.Such multi-model approach had never been investigated before.Due to the low-invasiveness of SPME,it was possible to perform time-course analysis,which allowed building time profile of biochemical reactions in the studied material.Such approach does not require the multiplication of samples as subsequent analyses are performed from the very same cell culture or from the same individual.SPME already reduces the number of animals required for experiment;therefore,it is with good concordance with the 3Rs rule(replacement,reduction,and refinement).Among tested models,the largest number of compounds was found within the in vitro 2D cell culture model,while in vivo and in vitro 3D models had the lowest number of detected compounds.These results may be connected with a higher metabolic rate,as well as lower integrity of the in vitro 2D model compared to the in vitro 3D model resulting in a lower number of compounds released into medium in the latter model.In terms of in vitro-in vivo extrapolation,the in vitro 2D model performed more similar to in vivo model compared to in vitro 3D model;however,it might have been due to the fact that only compounds secreted to medium were investigated.Thus,in further experiments to obtain full metabolome infor-mation,the intraspheroidal assessment or spheroid dissociation would be necessary.

Dispersive liquid-liquid microextraction,an effective tool for the determination of synthetic cannabinoids in oral fluid by liquid chromatography-tandem mass spectrometry / 药物分析学报

In the present work,dispersive liquid-liquid microextraction (DLLME) was used to extract six synthetic cannabinoids (JWH-018,JWH-019,JWH-073,JWH-200,or WIN 55,225,JWH-250,and AM-694) from oral fluids.A rapid baseline separation of the analytes was achieved on a bidentate octadecyl silica hydride phase (Cogent Bidentate C18;4.6 mm × 250 mm,4 μm) maintained at 37℃,by eluting in isocratic conditions (water:acetonitrile (25:75,V/V)).Detection was performed using positive electrospray ionization-tandem mass spectrometry.The parameters affecting DLLME (pH and ionic strength of the aqueous phase,type and volume of the extractant and dispersive solvent,vortex and centrifugation time)were optimized for maximizing yields.In particular,using 0.5 mL of oral fluid,acetonitrile (1 mL),was identified as the best option,both as a solvent to precipitate proteins and as a dispersing solvent in the DLLME procedure.To select an extraction solvent,a low transition temperature mixture (LTTM;composed of sesamol and chlorine chloride with a molar ratio of 1:3) and dichloromethane were compared;the latter (100 μL) was proved to be a better extractant,with recoveries ranging from 73％ to 101％ by vortexing for 2 min.The method was validated according to the guidelines of Food and Drug Administration bioanalytical methods:intra-day and inter-day precisions ranged between 4 ％ and 18 ％depending on the spike level and analyte;limits of detection spanned from 2 to 18 ng/mL;matrix-matched calibration curves were characterized by determination coefficients greater than 0.9914.Finally,the extraction procedure was compared with previous methods and with innovative techniques,presenting superior reliability,rapidity,simplicity,inexpensiveness,and efficiency.

Accurate and sensitive determination of hydroxychloroquine sulfate used on COVID-19 patients in human urine,serum and saliva samples by GC-MS / 药物分析学报

A rapid,accurate,and sensitive analytical method,ultrasonication-assisted spraying based fine droplet formation-liquid phase microextraction-gas chromatography-mass spectrometry (UA-SFDF-LPME-GC-MS),was proposed for the determination of trace amounts of hydroxychloroquine sulfate in human serum,urine,and saliva samples.To determine the best extraction strategy,several liquid and solid phase extraction methods were investigated for their efficiencies in isolation and preconcentration of hydroxychloroquine sulfate from biological matrices.The UA-SFDF-LPME method was determined to be the best extraction method as it was operationally simple and provided accurate results.Variables such as the extraction solvent,spraying number,sodium hydroxide concentration and volume,sample vol-ume,mixing method,and mixing period were optimized for the proposed method using the one-variable-at-a-time approach.In addition,Tukey's method based on a post hoc comparison test was employed to evaluate the significant difference between the parameters inspected.After the optimiza-tion studies,the limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.7 and 2.4 μg/kg,respectively.The sensitivity of the GC-MS system based on the LOD was enhanced approxi-mately 440-fold when the UA-SFDF-LPME method was employed.Spiking experiments were also con-ducted for the human serum,urine,and saliva samples to determine the applicability and accuracy of the proposed method.Recoveries for the human serum,urine,and saliva samples were found to be in the ranges of 93.9％-101.7％,95.2％-105.0％,and 93.1％-102.3％,respectively.These results were satisfactory and indicated that the hydroxychloroquine sulfate level in the above biological samples could be analyzed using the proposed method.

Determination of seven polycyclic aromatic hydrocarbons in water by dispersive liquid-liquid microextraction based on solidification of floating organic droplet with gas chromatography-mass spectrometry / 上海预防医学

Objective To develop a new method for the simultaneous determination of seven polycyclic aromatic hydrocarbons(PAHs)in water by dispersive liquid-liquid microextraction based on solidification of floating organic droplet(DLLME-SFO)with gas chromatography-mass spectrometry(GC-MS). Methods The experimental conditions of DLLME-SFO were determined with dodecanol as extractant solvent, methanol as dispersive solvent, inonic strength increased by adding 8% NaCl. After vortexed for 1 min and centrifuged at 4 000 r/min for 5 min, the water sample was cooled down in an ice bath till dodecanol became solid and formed a small ball. Then the solidified dodecanol phase was transferred, and directly detected by GC-MS method after it melted. Results Good linearities were obtained for the seven polycyclic aromatic hydrocarbons within the range of 5 μg/L-200 μg/L. The correlation coefficients were above 0.996. The detection limits ranged from 1.6 ng/L to 3.2 ng/L. The average recoveries ranged from 86.2% to 105% and the RSDs from 3.8% to 9.4%. Conclusion The method is sensitive, fast and simple. It has the advantage of little organic solvent consumption, which is friendly to environment and suitable for the detection of seven PAHs in water.

Establishment and Application of Identification Method for Fishy Odor of Cordyceps Based on HS-SPME/GC-QQQ-MS/MS / 中国实验方剂学杂志

Objective:To establish and apply a new practical analytical method for identifying the fishy odor of Cordyceps based on headspace-solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry （HS-SPME/GC-QQQ-MS/MS） technique. Method:The InertCap Pure-WAX capillary column （0.25 mm×30 m， 0.25 μm） was used for chromatographic separation. The injection port temperature was set at 250 ℃. The injection mode was split injection with a ratio of 5∶1. High purity helium was used as the carrier gas and control mode was set to constant pressure. The column flow rate was 1.43 mL∙min^-1， the linear velocity was 43.3 cm∙s^-1， and the purge flow rate was 3.0 mL∙min^-1. The chromatographic column temperature program as follows：maintained the initial temperature at 50 ℃ for 5 min， and increased the temperature at a rate of 10 ℃∙min^-1 to 250 ℃， held for 10 min. The column equilibrium time was 2.0 min. The ion source of mass spectrographic analysis was electron ionization with ion source temperature of 200 ℃， and the monitoring mode was set to multiple reaction monitoring. Result:Seven batches of Cordyceps samples were collected， including 3 batches from Sichuan， 3 batches from Qinghai and 1 batch from Tibet. There were six batches of counterfeits， including 3 batches from Sichuan， 2 batches from Guizhou and 1 batch in Xinjiang. A total of 81 volatile compounds were screened out in Cordyceps， which could be divided into 13 types （esters， ketones， aldehydes and others） according to the compound structure， indicating that the fishy odor of Cordyceps was a complex odor. There was no significant difference in the types of volatile compounds of Cordyceps from different regions， which suggested that these volatile compounds in Cordyceps produced in Tibet （Naqu）， Qinghai （Yushu and Guoluo） and Sichuan （Litang， Rangtang and Seda） were relatively consistent. However， the contents of some volatile compounds in Cordyceps produced in different regions were quite different， and 16 volatile compounds with significant difference were screened out， including 1-methoxy-2-propyl acetate， <italic>γ</italic>-octalactone， hexyl acetate and others， those compounds maybe could been used as the quality markers for identification of regions of Cordyceps. There was a large difference in volatile compounds between Cordyceps and its counterfeits， and 34 volatile compounds were screened out， including ethyl acetate， acetophenone， 2-ethyl-1-hexanol and others， those compounds maybe could been used as the quality markers for authenticity identification of Cordyceps. Conclusion:In summary， the established method for identifying the fishy odor of Cordyceps in this paper has the characteristics of high sensitivity， accuracy and simplicity， which can provide reference for the analysis of volatile compounds in other Chinese herbal medicines.

Development of a liquid-liquid microextraction GC-MS method for simultaneous determination and pharmacokinetic analysis of β- elemene in rat plasma after administration of citronella grass extract / 药学学报

We established a simple and sensitive GC-MS method for the determination of β-elemene in rat plasma and measured the pharmacokinetics of citronella grass extract in rats. Plasma samples were pretreated using liquid-liquid microextraction: 100 μL of plasma sample (containing naphthalene as the internal standard) was extracted with 50 μL of n-hexane. The determination was performed on DB-5ms column (30 m×0.25 mm, 0.25 μm). The initial column temperature was 60 ℃ and raised to 160 ℃ at a rate of 50 ℃·min-1, maintained for 3 min, and finally increased to 260 ℃ for 3 min. Helium was the carrier gas and the flow rate was 0.15 mL·min-1. The injection volume was 2 μL. EI and selected monitored ions pattern were used for ion scanning with m/z 128 (naphthalene) and m/z 93 (β-elemene). Citronella grass extract was administered to rats by intragastric administration and intravenous administration (containing β-elemene 55 mg·kg-1), and plasma was collected and prepared using an automated blood collection system. The linear range of β-elemene in plasma was 1.0-250 ng·mL-1 (r = 0.997), the limit of quantification was 1.0 ng·mL-1, the accuracy was -4.47% - -0.85%, the extraction recovery was between 56.02%-66.89%, and no obvious matrix effect (94.28%-108.63%) was found. The main pharmacokinetic parameters of β-elemene were AUC0-t (23.56 ± 4.40) ng·mL-1, tmax (1.67 ± 0.58) h, Cmax (7.36 ± 0.69) ng·mL-1, MRT0-t (2.76 ± 0.27) h, t1/2z (2.73 ± 1.36) h, Vz (7.39 ± 3.18) L·kg-1, CLz (1.95 ± 0.51) L·h-1·kg-1, and the absolute bioavailability was about 8.78%. The method is simple, accurate, and sensitive, and is suitable for the pharmacokinetic analysis of β-elemene in citronella grass extract in rats. All animal studies were implemented according to protocols, which were reviewed and approved by the Institutional Animal Care and Use Committee at Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences.