Application of ultrahigh-performance liquid chromatography coupled with mass spectrometry for analysis of lignans and quality control of Fructus Schisandrae chinensis

Lignans in the drug Fructus Schisandrae chinensis (FSC) exhibit potent biological activities such as antihepatotoxic, antiasthmatic, and antigastric ulcer. An ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method has been developed to evaluate the quality of FSC through simultaneous qualitative and quantitative analysis of 15 lignans, including schizandrin A, B, and C; schizandrol A and B; gomisin B, C, D, E, G, H, J, and N; tigloylgomisin H; and angeloylgomisin H. The compounds were separated on a Zorbax Eclipse Plus C(18) (2.1 × 100 mm, 1.8 μm) column with a gradient elution of acetonitrile and 0.1% formic acid. Lignans were identified through their retention times, accurate mass data, and characteristic ions by comparison with a reference substance. All calibration curves showed perfect linear regression (r(2) > 0.99) within the test range. The limits of detection and quantitation fell in the ranges of 0.1-4 ng/mL for all the analytes with an injection of 10 μL. Good results were obtained with respect to repeatability (relative standard deviation <4.6%) and recovery (85.58-105.82%). Meanwhile, the entire sample analysis time was less than 10 min. This developed method provided a new basis for the overall assessment of the quality of FSC.     

Stereoselective determination of dufulin in watermelon under field conditions using chiral ultra high performance liquid chromatography with high‐resolution mass spectrometry

An effective and sensitive chiral analytical method was established to investigate the stereoselective dissipation of rac‐dufulin in watermelon using ultra high performance liquid chromatography with a superchiral S‐OD chiral column (4.6 × 150 mm i.d., 5 μm) coupled with high‐resolution mass spectrometry. To optimize the pretreatment method for detecting rac‐dufulin in the three matrixes, different extraction solvents, extractant volumes, extraction times, and absorbents were investigated to improve extraction efficiency. Moreover, analysis of variance was used to perform method validation for determination of the two dufulin enantiomers in the three matrixes. Using the optimized method, good linearity was obtained (determination coefficient > 0.999). The limits of detection and quantification of the two dufulin enantiomers in soil, watermelon, and pulp were 0.15 and 0.5 μg/kg, respectively. The average recoveries of the two enantiomers in the three matrixes at four spiked levels ranged from 75.0 to 107.8%, with intra‐ and inter‐day relative standard deviations of 0.4–10.4%. In field trials, the R enantiomer was preferentially dissipated in watermelon. These method validation results confirmed that the developed method was convenient and reliable for the stereoselective determination of enantiomers of rac‐dufulin in watermelon.     

Fast and sensitive analysis of beta blockers by ultra‐high‐performance liquid chromatography coupled with ultra‐high‐resolution TOF mass spectrometry

This paper presents a method for the determination of acebutolol, betaxolol, bisoprolol, metoprolol, nebivolol and sotalol in human serum by liquid–liquid extraction and ultra‐high‐performance liquid chromatography coupled with ultra‐high‐resolution TOF mass spectrometry. After liquid–liquid extraction, beta blockers were separated on a reverse‐phase analytical column (Acclaim RS 120; 100 × 2.1 mm, 2.2 μm). The total run time was 6 min for each sample. Linearity, limit of detection, limit of quantification, matrix effects, specificity, precision, accuracy, recovery and sample stability were evaluated. The method was successfully applied to the therapeutic drug monitoring of 108 patients with hypertension. This method was also used for determination of beta blockers in 33 intoxicated patients.     

Rapid quantification of pharmaceuticals and pesticides in passive samplers using ultra high performance liquid chromatography coupled to high resolution mass spectrometry

The presence of both pharmaceuticals and pesticides in the aquatic environment has become a well-known environmental issue during the last decade. An increasing demand however still exists for sensitive and reliable monitoring tools for these rather polar contaminants in the marine environment. In recent years, the great potential of passive samplers or equilibrium based sampling techniques for evaluation of the fate of these contaminants has been shown in literature. Therefore, we developed a new analytical method for the quantification of a high number of pharmaceuticals and pesticides in passive sampling devices. The analytical procedure consisted of extraction using 1:1 methanol/acetonitrile followed by detection with ultra-high performance liquid chromatography coupled to high resolution and high mass accuracy Orbitrap mass spectrometry. Validation of the analytical method resulted in limits of quantification and recoveries ranging between 0.2 and 20 ng per sampler sheet and between 87.9 and 105.2%, respectively. Determination of the sampler-water partition coefficients of all compounds demonstrated that several pharmaceuticals and most pesticides exert a high affinity for the polydimethylsiloxane passive samplers. Finally, the developed analytical methods were used to measure the time-weighted average (TWA) concentrations of the targeted pollutants in passive samplers, deployed at eight stations in the Belgian coastal zone. Propranolol, carbamazepine and seven pesticides were found to be very abundant in the passive samplers. These obtained long-term and large-scale TWA concentrations will contribute in assessing the environmental and human health risk of these emerging pollutants.     

Comprehensive characterization of multiple components and metabolites of Xiaojin Capsule based on ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry

Xiaojin Capsule, a classic traditional Chinese medicine formula, has been used to treat mammary cancer, thyroid nodules, and hyperplasia of the mammary glands. However, its systematic chemical information remained unclear, which hindered the interpretation of the pharmacology and the mechanism of action of this drug. In this research, an ultra high performance liquid chromatography coupled with a quadrupole time‐of‐flight mass spectrometry method was developed to identify the complicated components and metabolites of Xiaojin Capsule. Two acquisition modes, including the MS^Energy mode and fast data directed acquisition mode, were utilized for chemical profiling. As a result, 156 compounds were unambiguously or tentatively identified by comparing their retention times and mass spectrometry data with those of reference standards or literature. After the oral administration of Xiaojin Capsule, 53 constituents, including 24 prototype compounds and 29 metabolites, were detected in rat plasma. The obtained results were beneficial for a better understanding of the therapeutic basis of Xiaojin Capsule. A high‐resolution and efficient separation method was firstly established for systematically characterizing the compounds of Xiaojin Capsule and the associated metabolites in vivo, which could be helpful for quality control and pharmacokinetic studies of this medicine.     

Characterization of the potential new phthalides in Ligusticum chuanxiong Hort. using ultra‐performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry

The characterization of unknown compounds is still a great challenge currently. A strategy for deduction of potential new phthalides through the characterization of isomers based on ultra‐performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry was proposed here to characterize the unknown compounds of Ligusticum chuanxiong Hort. (Chuanxiong). This proposed strategy consisted of four steps: (1) the high resolution MS data was collected, and the peaks were screened preliminarily by UNIFI^TM platform based on the in‐house database; (2) the fragmentation patterns and the characteristic fragments were summarized based on the representative standards; (3) the target compounds were identified based on the fragmentation rules, standards comparison and false positive exclusion; (4) the unknown components were structurally characterized according to the accurate mass and fragmentation patterns analysis. This strategy was successfully applied to the identification and deduction of phthalides in Chuanxiong. A total of 81 phthalides were detected. Fifty‐five known phthalides were identified, and 26 potential new phthalides were characterized. This research enriched the material basis of Chuanxiong, and provided a liquid chromatography tandem mass spectrometry‐oriented method for the discovery of the potential new compounds.     

Coupling nanoliter high‐performance liquid chromatography to inductively coupled plasma mass spectrometry for arsenic speciation

Nanoliter high‐performance liquid chromatography shows low consumption of solvents and samples, offering one of the best choices for arsenic speciation in precious samples in combination with inuctively coupled plasma mass spectrometry. A systematic investigation on coupling nanoliter high‐performance liquid chromatography to inductively coupled plasma mass spectrometry from instrument design to injected sample volume and mobile phase was performed in this study. Nanoflow mobile phase was delivered by flow splitting using a conventional high‐pressure pump with reuse of mobile phase waste. Dead volume was minimized to 60 nL for the sheathless interface based on the previously developed nanonebulizer. Capillary columns for nanoliter high‐performance liquid chromatography were found to be sensitive to sample loading volume. An apparent difference was also found between the mobile phases for nanoliter and conventional high‐performance liquid chromatography. Baseline separation of arsenite, arsenate, monomethylarsenic, and dimethylarsenic was achieved within 11 min on a 15 cm C₁₈ capillary column and within 12 min on a 25 cm strong anion exchange column. Detection limits of 0.9–1.8 μg/L were obtained with precisions variable in the range of 1.6–4.2%. A good agreement between determined and certified values of a certified reference material of human urine (GBW 09115) validated its accuracy along with good recoveries (87–102%).     

Novel approaches in analysis of Fusarium mycotoxins in cereals employing ultra performance liquid chromatography coupled with high resolution mass spectrometry

Rapid, simple and cost-effective analytical methods with performance characteristics matching regulatory requirements are needed for effective control of occurrence of Fusarium toxins in cereals and cereal-based products to which they might be transferred during processing. Within this study, two alternative approaches enabling retrospective data analysis and identification of unknown signals in sample extracts have been implemented and validated for determination of 11 major Fusarium toxins. In both cases, ultra-high performance liquid chromatography (U-HPLC) coupled with high resolution mass spectrometry (HR MS) was employed. ¹³C isotopically labeled surrogates as well as matrix-matched standards were employed for quantification. As far as time of flight mass analyzer (TOF-MS) was a detection tool, the use of modified QuEChERS (quick easy cheap effective rugged and safe) sample preparation procedure, widely employed in multi-pesticides residue analysis, was shown as an optimal approach to obtain low detection limits. The second challenging alternative, enabling direct analysis of crude extract, was the use of mass analyzer based on Orbitrap technology. In addition to demonstration of full compliance of the new methods with Commission Regulation (EC) No. 401/2006, also their potential to be used for confirmatory purposes according to Commission Decision 2002/657/EC has been critically assessed.     

Chemical fingerprint of Ganmaoling granule by double‐wavelength ultra high performance liquid chromatography and ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry

A method incorporating double‐wavelength ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry was developed for the investigation of the chemical fingerprint of Ganmaoling granule. The chromatographic separations were performed on an ACQUITY UPLC HSS C₁₈ column (2.1 × 50 mm, 1.8 μm) at 30°C using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. A total of 11 chemical constituents of Ganmaoling granule were identified from their molecular weight, UV spectra, tandem mass spectrometry data, and retention behavior by comparing the results with those of the reference standards or literature. And 25 peaks were selected as the common peaks for fingerprint analysis to evaluate the similarities among 25 batches of Ganmaoling granule. The results of principal component analysis and orthogonal projection to latent structures discriminant analysis showed that the important chemical markers that could distinguish the different batches were revealed as 4,5‐di‐O‐caffeoylquinic acid, 3,5‐di‐O‐caffeoylquinic acid, and 4‐O‐caffeoylquinic acid. This is the first report of the ultra high performance liquid chromatography chemical fingerprint and component identification of Ganmaoling granule, which could lay a foundation for further studies of Ganmaoling granule.     

Recent applications of gas chromatography with high‐resolution mass spectrometry

Gas chromatography coupled to high‐resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high‐resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi‐volatile organic compounds. Gas chromatography with high‐resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high‐resolution time‐of‐flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi‐target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high‐resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high‐resolution mass spectrometry for non‐target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high‐resolution mass spectrometry over the currently used methods is expected, will be discussed as well.     

Analysis of selected designer benzodiazepines by ultra high performance liquid chromatography with high‐resolution time‐of‐flight mass spectrometry and the estimation of their partition coefficients by micellar electrokinetic chromatography

A new ultra high performance liquid chromatography with electrospray ionization time of flight mass spectrometry method for the selective and sensitive separation, identification, and determination of selected designer benzodiazepines (namely, pyrazolam, phenazepam, etizolam, flubromazepam, diclazepam, deschloroetizolam, bentazepam, nimetazepam, and flubromazolam) in human serum was developed. The separation of the studied designer benzodiazepines was achieved on C₁₈ chromatographic column using gradient elution within 6 min without any significant matrix interferences. Liquid–liquid extraction with butyl acetate was applied for serum samples cleanup and preconcentration of studied designer benzodiazepines. The method was validated in terms of linearity, limit of detection, limit of quantification, matrix effects, specificity, precision, accuracy, recovery, and sample stability. The limit of detection values were 0.10–0.15 ng/mL. The method was applied to a spiked serum sample to demonstrate its applicability for systematic toxicology analysis. Furthermore, a capillary chromatographic method with micellar electrokinetic chromatography was used for the estimation of partition coefficients of studied designer benzodiazepines as important parameters to evaluate their pharmacological and toxicological properties.     

超高效液相色谱-四极杆飞行时间质谱法用于食物中毒的快速筛查与确证

建立了一种利用超高效液相色谱-四极杆飞行时间质谱筛查食物中毒的方法。试样用乙腈提取,QuEChERS净化,以0.1%(v/v)甲酸水溶液和0.1%(v/v)甲酸乙腈溶液为流动相进行梯度洗脱,经Acquity UPLC BEH C18柱(100 mm×2.1 mm,1.7μm)分离。采用四极杆飞行时间质谱信息依赖性扫描(information dependent acquisition,IDA)模式进行分析。该模式可以实现一次进样分析同时获得分析物的一级和二级碎片的精确质量质谱图,结合SCIEX OS软件可对581种目标物质进行快速筛查,其中包括546种农药、24种真菌毒素、11种鼠药,以一级离子精确质量数、一级离子同位素丰度比以及二级碎片进行标准质谱库匹配。应用建立的快速筛选确认检测方法对一起突发性食物中毒安全事件样本进行检测,共检测11份样本,其中9份均检测出呋喃丹。进一步以呋喃丹标准品确认保留时间,结果表明,样品与标准品保留时间一致。呋喃丹的精确质量数偏差均小于3.7×10-6,在0.5~500 ng/mL范围内线性关系良好,相关系数为0.998,仪器检出限(S/N=3)为0.3μg/kg,定量限(S/N=10)为1μg/kg,在10、50、200μg/kg 3个添加水平的回收率为75.6%~95.9%,相对标准偏差为3.6%~6.9%(n=6)。该方法快速、简便、准确、灵敏,适用于突发性公共安全事件的快速筛查与检测要求。     

A method based on precolumn derivatization and ultra high performance liquid chromatography with high‐resolution mass spectrometry for the simultaneous determination of phthalimide and phthalic acid in tea

Phthalimide can be formed from either the degradation of folpet and phosmet, or reaction of phthalic anhydride with primary amino groups. Consequently, the sum of phthalimide and folpet, expressed as folpet‐residue definition, is highly prone to false‐positive levels of folpet in tea. An analytical method is thus urgently needed to investigate the residue level and source of phthalimide in tea. In this work, we developed an accurate method of determining phthalimide and phthalic acid (the indicator of phthalic anhydride) by acetonitrile extraction and 3‐bromopropyltrimethylammonium bromide derivatization coupled with ultra high performance liquid chromatography and high‐resolution mass spectrometry. The method was validated, and linearity (correlation coefficients > 0.99) was obtained. Satisfactory recoveries at 10, 20, 50, and 100 μg/kg ranged from 76 to 117%, and the intra‐ and interday accuracies were <23%. The limit of quantification for phthalimide and phthalic acid was 10 μg/kg. The developed method was further successfully used to determine phthalimide and phthalic acid in some tea samples. The positive rate of phthalimide and phthalic acid detected in the tea samples ranged from 30–75 and 50–90%, respectively.     

Chemometrics for comprehensive analysis of nucleobases,nucleosides, and nucleotides in Siraitiae Fructus by hydrophilic interaction ultra high performance liquid chromatography coupled with triple‐quadrupole linear ion‐trap tandem mass spectrometry

A rapid and sensitive hydrophilic interaction ultra high performance liquid chromatography coupled with triple‐quadrupole linear ion‐trap tandem mass spectrometry method was validated for the simultaneous determination of 20 nucleobases, nucleosides, and nucleotides (within 3.5 min), and then was employed to test the functional food of Luo‐Han‐Guo samples. The analysis showed that the Luo‐Han‐Guo was rich in guanosine and uridine, but contained trace levels of the other target compounds. Chemometrics methods were employed to identify 40 batches of Luo‐Han‐Guo samples from different cultivated forms, regions and varieties. Unsupervised hierarchical cluster analysis and principal component analysis were used to classify Luo‐Han‐Guo samples based on the level of the 20 target compounds, and the supervised learning method of counter propagation artificial neural network was utilized to further separate clusters and validate the established model. As a result, the samples could be clustered into three primary groups, in which correlation with cultivated varieties was observed. The present strategy could be applied to the investigation of other edible plants containing nucleobases, nucleosides, or nucleotides.     

超高效液相色谱-串联质谱法测定人尿液中全氟有机化合物

采用超高效液相色谱-串联质谱(UPLC-MS/MS)联用技术,建立了对人尿液中12种全氟有机化合物(PFCs)的分析方法。首先在尿液样品中加入相应的同位素内标,以2%(体积分数)甲酸甲醇溶液超声萃取、离心后,将提取液用弱阴离子交换固相萃取柱净化,采用UPLC-MS/MS测定,内标法定量。12种目标化合物在0.05～50 μg/L质量浓度范围内线性良好,相关系数(r)均大于0.992,检出限在0.44～3.47 ng/L之间。在20、100、500 ng/L添加水平下,平均回收率范围为80.3%～116.2%,相对标准偏差(n=6)在5.5%～13.8%之间。该方法灵敏度高、重现性好、回收率高、操作简单,适合人尿液中PFCs的测定。     

Pharmacokinetic and metabolism studies of bavachinin through ultra‐high‐performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry

Bavachinin (BVC), one of the main bioactive prenylated flavonoids derived from Psoralea corylifolia Linn, has a wide variety of pharmacological effects, such as antiangiogenic, antitumor, antiallergic, anti‐inflammatory and antibacterial activities, especially as a pan‐peroxisome proliferator‐activated receptors agonist. A rapid and sensitive method for quantifying BVC in rat plasma was developed and validated through ultra‐high‐performance liquid chromatography coupled with electrospray‐ionization tandem mass spectrometry. Furthermore, a complete metabolic investigation of BVC was performed through ultra‐high‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry. In the pharmacokinetic analysis, BVC exhibited rapid oral absorption (T_max = 0.68 ± 0.21 h), good elimination (T_1/2 = 2.27 ± 1.63 h) following oral administration and poor absolute bioavailability (5.27%). Moreover, 11 metabolites of BVC in plasma, urine, bile and feces were characterized. The main metabolic pathways of BVC involved isomeriszation, glucuronidation, sulfonation, hydroxylation, methoxylation and reduction. In conclusion, the present study provides a sensitive quantitative method with a lower limit of quantification of 1 ng/mL and an improved comprehension of the physiological disposition of BVC.     

New approach to the determination phosphorothioate oligonucleotides by ultra high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry

This text presents a novel method for the separation and detection of phosphorothioate oligonucleotides with the use of ion pair ultra high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry The research showed that hexafluoroisopropanol/triethylamine based mobile phases may be successfully used when liquid chromatography is coupled with such elemental detection. However, the concentration of both HFIP and TEA influences the final result. The lower concentration of HFIP, the lower the background in ICP-MS and the greater the sensitivity. The method applied for the analysis of serum samples was based on high resolution inductively coupled plasma mass spectrometry. Utilization of this method allows determination of fifty times lower quantity of phosphorothioate oligonucleotides than in the case of quadrupole mass analyzer. Monitoring of ³¹P may be used to quantify these compounds at the level of 80 μg L⁻¹, while simultaneous determination of sulfur is very useful for qualitative analysis. Moreover, the results presented in this paper demonstrate the practical applicability of coupling LC with ICP-MS in determining phosphorothioate oligonucleotides and their metabolites in serum within 7 min with a very good sensitivity. The method was linear in the concentration range between 0.2 and 3 mg L⁻¹. The limit of detection was in the range of 0.07 and 0.13 mg L⁻¹. Accuracy varied with concentration, but was in the range of 3%.     

Applying characteristic fragment filtering for rapid detection and identification of ingredients in rhubarb by HPLC coupled with linear ion trap–Orbitrap mass spectrometry

Chemical characteristic fragment filtering in MSⁿ chromatograms was proposed to detect and identify the components in rhubarb rapidly using high‐performance liquid chromatography coupled with linear ion trap–Orbitrap mass spectrometry. Characteristic fragments consist of diagnostic ions and neutral loss fragments. Characteristic fragment filtering is a postacquisition data mining method for the targeted screening of groups with specific structures, including three steps: first, in order to comprehensively summarize characteristic fragments for global identification of the ingredients in rhubarb, representative authentic standards of dominant chemical categories contained in rhubarb were chosen, from which fragmentation rules and a characteristic fragments schedule were proposed; second, characteristic fragment filtering was used to rapidly recognize analogous skeletons; finally, combined with retention time, accurate mass, characteristic fragments, and previous literature, the structures of the filtered compounds were identified or tentatively characterized. As a result, a total of 271 compounds were detected and identified in rhubarb, including 34 anthraquinones, 83 anthrones, 46 tannins, 17 stilbenes, 24 phenylbutanones, 26 acylglucosides, 26 chromones, and 15 other compounds, 69 of which are potentially new compounds. The proposed characteristic fragment filtering strategy would be a reference for the large‐scale detection and identification of the ingredients of herbal medicines.