Combination of the advantages of chromatographic methods based on active components for the quality evaluation of licorice

A rapid, improved and comprehensive method including high‐performance thin‐layer chromatography, fingerprint technology and single standard to determine multiple components was developed and validated for the quality evaluation of licorice. In this study, a newly developed high‐performance thin‐layer chromatography method was first used for authentication of licorice, which achieved simultaneous identification of multiple bands including five bands for known bioactive components by comparing their retention factor values and colors with the standards. For fingerprint analysis, 8 of 16 common peaks were identified. Simultaneously, similarity analysis which showed very similar patterns and hierarchical clustering analysis were performed to discriminate and classify the 27 batches of samples. Additionally, the single standard to determine multiple components method was first successfully achieved to quantify the eight important active markers in licorice including liquiritin apioside, liquiritin, isoliquiritin apioside, isoliquritin, neoisoliquiritin, liquiritigenin, isoliquiritigenin and glycyrrhizic acid. The easily available glycyrrhizic acid was selected as the reference substance to calculate relative response factors. Compared with the normal external standard method, this alternative method can be used to determine the multiple indices effectively and accurately. The validation result showed that the developed method was specific, accurate, precise, robust and reliable for the overall quality assessment of licorice.     

Multi‐constituent determination and fingerprint analysis of Scutellaria indica L. using ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry

An ultra‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method integrating multi‐constituent determination and fingerprint analysis has been established for quality assessment and control of Scutellaria indica L. The optimized method possesses the advantages of speediness, efficiency, and allows multi‐constituents determination and fingerprint analysis in one chromatographic run within 11 min. 36 compounds were detected, and 23 of them were unequivocally identified or tentatively assigned. The established fingerprint method was applied to the analysis of ten S. indica samples from different geographic locations. The quality assessment was achieved by using principal component analysis. The proposed method is useful and reliable for the characterization of multi‐constituents in a complex chemical system and the overall quality assessment of S. indica.     

Validation of an LC–MS/MS method for simultaneous detection of diverse components of Qinxing Qingre Zhike Granule in rat plasma and its application to pharmacokinetic study after oral administration to rats

A sensitive and validated method of liquid chromatography–tandem mass spectrometry (LC–MS/MS) was established to test the plasma concentrations of active ingredients in Qinxing Qingre Zhike Granule, namely geniposide, liquiritin, isoliquiritin, baicalin, wogonoside, baicalein, liquiritigenin, isoliquiritigenin and glycyrrhetinic acid. The analysis was performed on an Ultimate XB‐C₁₈ column at the flow rate of 0.4 mL min^?1 in a single run of 18 min. The mobile phase was composed of 0.05% formic acid in water and acetonitrile with gradient elution. Positive and negative scanning and selected multiple reaction monitoring modes were applied for quantization. The proposed method showed good linearity in the given ranges from 0.6800–340.0 to 3.920–1960 ng mL^?1 with r² > 0.9917 for all the analytes. The precision (RSD) was no more than 12%, and the accuracy (RE) was less than ±11% for intra‐ and inter‐day. The extract recovery and matrix effect were acceptable for the requirements of biological sample analysis. Moreover, the developed method was effectively applied to the pharmacokinetic investigation of Qinxing Qingre Zhike Granule after oral administration in rats.     

UPLC–Q‐TOF–MS and UPLC–MS/MS methods for metabolism profiles and pharmacokinetics of major compounds in Xuanmai Ganjie Granules

Xuanmai Ganjie Granules (XMGJ), a widely used Chinese herbal formula in the clinic, is used for treatment of sore throats and coughs. Despite the chemical constituents having been clarifying by our previous studies, both of the metabolism and pharmacokinetic studies of XMGJ are unclear. This study aimed to explore the disposition process of XMGJ in vivo. A sensitive and selective ultra‐high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry (UPLC–Q‐TOF–MS) method was developed to analyze the absorbed components and metabolites in rat plasma and urine after oral administration of XMGJ. A total of 42 absorbed components, including 16 prototype compounds and 26 metabolites, were identified or tentatively characterized in rat plasma and urine after oral administration of XMGJ. Moreover, the pharmacokinetic studies of five compounds of XMGJ were investigated using ultra‐high liquid chromatography with tandem mass spectrometry method. The results indicated that liquiritin, harpagoside, glycyrrhetic acid, liquiritigenin, formononetin and their metabolites might be the major components involved in the pharmacokinetic and metabolism process of XMGJ. This research showed a comprehensive investigation of XMGJ in vivo, which could provide a meaningful basis for further material basis and pharmacological as well as toxicological research.     

Comparative pharmacokinetics of nine major bioactive components in normal and ulcerative colitis rats after oral administration of Lizhong decoction extracts by UPLC–TQ–MS/MS

Lizhong decoction (LZD), a classic formula, has been used to treat ulcerative colitis (UC) for thousands of years in clinical practice. However, the pharmacokinetic characteristics of its major bioactive components in rats under different physiological and pathological states are not clear. Thus, in this study, a rapid and sensitive analytical method, ultra‐performance liquid chromatography coupled with mass spectrometry (UPLC–MS/MS) method, was developed and applied to simultaneously determine glycyrrhizic acid, liquiritin, isoliquiritin, glycyrrhizin, isoliquiritigenin, 6‐gingerol, ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Re in normal and UC rats after oral administration of LZD extract. A Waters BEH C₁₈ UPLC column was used for chromatographic separation, while acetonitrile and 0.1% formic acid were selected as mobile phase. The linearity of nine analytes was >0.9920. Inter‐ and intra‐day accuracy was ≤ 11.4% and precision was from 1.1 to 12.7%. Additionally, stable and suitable extraction recoveries were also obtained. The established method was validated and found to be specific, accurate and precise for nine analytes. Furthermore, it was successfully applied to the pharmacokinetic investigation of nine major components after oral administration of LZD extracts to normal and model rats, respectively. The results showed that the pharmacokinetic parameters (C_max, T_max, AUC_0–t, AUC_0–∞) in the plasma of UC rats were significantly different from those of normal rats, which could provide a reference for the clinical application of LZD.     

Simultaneous determination of multiple active components in rat plasma using ultra‐fast liquid chromatography with tandem mass spectrometry and application to a comparative pharmacokinetic study after oral administration of Suan‐Zao‐Ren decoction and Suan‐Zao‐Ren granule

Suan‐Zao‐Ren decoction has been used to treat insomnia for many years. In this work, a rapid and sensitive ultra‐fast liquid chromatography with tandem mass spectrometry method was first developed and fully validated for the simultaneous quantification of seven main active components, spinosin, mangiferin, neomangiferin, ferulic acid, liquiritin, isoliquiritin, and liquiritin apioside in rat plasma. The method was also successfully applied to compare the pharmacokinetics of these active ingredients after oral administration of Suan‐Zao‐Ren decoction and Suan‐Zao‐Ren granule. The separation was achieved on a Venusil MP C₁₈ column and the detection was conducted by the multiple reaction monitoring mode using negative ion mode. Each calibration curve had good linearity over a wide concentration range. The precision of intra‐ and interday were all within 15%, and the extraction recoveries at different analyte concentrations were all above 82.0%. The established method was successfully applied to compare the pharmacokinetic profiles of the analytes between Suan‐Zao‐Ren decoction and Suan‐Zao‐Ren granule groups. The results indicated that all the analytes had similar mean concentration‐time curves trend between two groups. No significant differences were observed in pharmacokinetic parameters of mangiferin, while the others had significant differences.     

Relationship between the UPLC‐Q‐TOF‐MS fingerprinted constituents from Daphne genkwa and their anti‐inflammatory,anti‐oxidant activities

Daphne genkwa Sieb.et Zucc. is a well‐known medicinal plant. This study was designed to apply the ultra‐high performance liquid chromatography system to establish a quality control method for D. genkwa. Data revealed that there were 15 common peaks in 10 batches of D. genkwa Sieb. Et Zucc. (Thymelaeaceae) from different provinces of China. On this basis, the fingerprint chromatogram was established to provide references for quality control. Afterwards, the chemical constitutions of these common peaks were analyzed using the UPLC‐Q‐TOF‐MS system and nine of them were identified. In addition, LPS‐stimulated RAW264.7 murine macrophages and DPPH assay were used to study the anti‐inflammatory and anti‐oxidation effects of D. genkwa . Then the fingerprint–efficacy relationships between UPLC fingerprints and pharmacodynamic data were studied with canonical correlation analysis. Analysis results indicated that the anti‐inflammatory and anti‐oxidation effects differed among the 10 D. genkwa samples owing to their inherent differences of chemical compositions. Taken together, this research established a fingerprint–efficacy relationship model of D. genkwa plant by combining the UPLC analytic technique and pharmacological research, which provided references for the detection of the principal components of traditional Chinese medicine on bioactivity.     

Analysis of aflatoxins in nonalcoholic beer using liquid–liquid extraction and ultraperformance LC‐MS/MS

Aflatoxins AFB1, AFB2, AFG1, and AFG2 are toxic secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus and posses a potential threat to food safety. In the present work, liquid–liquid extraction and ultraperformance LC‐MS/MS method has been applied for the determination of four naturally occurring aflatoxins AFB1, AFB2, AFG1, and AFG2 in nonalcoholic beer. Aflatoxins extraction from nonalcoholic beer was carried out using liquid–liquid extraction procedure. The effects of solvent‐types were studied to obtain maximum recovery of the target analytes with minimum contamination. Among different solvents, the aflatoxins extraction was best achieved using ethyl acetate. The obtained recoveries were ranged from 85 to 96% with good quality parameters: LOD values between 0.001 and 0.003 ng/mL, linearity of the calibration curve (r² > 0.999), and repeatability (run‐to‐run) and reproducibility (day‐to‐day) precisions with RSDs lower than 5% (n = 5) achieved at 0.50 ng/mL concentration. The optimized liquid–liquid extraction in combination with ultraperformance LC‐MS/MS was applied successfully to the analysis of AFB1, AFB2, AFG1, and AFG2 aflatoxins in 11 nonalcoholic beers and were detected up to 15.31 ng/L in some of the samples.     

Preparative isolation and analysis of alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root using ultrafiltration combined with high‐performance liquid chromatography and high‐speed countercurrent chromatography

A simple, rapid, and effective assay based on ultrafiltration combined with high‐performance liquid chromatography and high‐speed countercurrent chromatography was developed for screening and purifying alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root extract. Experiments were carried out to optimize binding conditions including alcohol dehydrogenase concentration, incubation time, temperature, and pH. By comparing the chromatograms, three compounds were found possessing alcohol dehydrogenase binding activity in Glycyrrhiza uralensis root. Under the target‐guidance of ultrafiltration combined with the high‐performance liquid chromatography experiment, liquiritin ( 1 ), isoliquiritin ( 2 ), and liquiritigenin ( 3 ) were separated by high‐speed countercurrent chromatography using ethyl acetate/methanol/water (5:1:4) as the solvent system. The alcohol dehydrogenase inhibitory activities of these three isolated compounds were assessed; compound 2 showed strongest inhibitory activity with an IC₅₀ of 8.95 μM. The results of the present study indicated that the combinative method using ultrafiltration, high‐performance liquid chromatography and high‐speed countercurrent chromatography could be widely applied for the rapid screening and isolation of enzyme inhibitors from complex mixtures.     

Determination and Fingerprint Analysis of Steroidal Saponins in roots of Liriope muscari (Decne.) L. H. Bailey by ultra high performance liquid chromatography coupled with ion trap time‐of‐flight mass spectrometry

Liriope muscari (Decne.) L. H. Bailey is a well‐known traditional Chinese medicine used for treating cough and insomnia. There are few reports on the quality evaluation of this herb partly because the major steroid saponins are not readily identified by UV detectors and are not easily isolated due to the existence of many similar isomers. In this study, a qualitative and quantitative method was developed to analyze the major components in L. muscari (Decne.) L. H. Bailey roots. Sixteen components were deduced and identified primarily by the information obtained from ultra high performance liquid chromatography with ion‐trap time‐of‐flight mass spectrometry. The method demonstrated the desired specificity, linearity, stability, precision, and accuracy for simultaneous determination of 15 constituents (13 steroidal glycosides, 25(R)‐ruscogenin, and pentylbenzoate) in 26 samples from different origins. The fingerprint was established, and the evaluation was achieved using similarity analysis and principal component analysis of 15 fingerprint peaks from 26 samples by ultra high performance liquid chromatography. The results from similarity analysis were consistent with those of principal component analysis. All results suggest that the established method could be applied effectively to the determination of multi‐ingredients and fingerprint analysis of steroid saponins for quality assessment and control of L. muscari (Decne.) L. H. Bailey.     

Ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry and chemometric analysis of licorice based on the simultaneous determination of saponins and flavonoids

Licorice is among the most popular herbal medicines and frequently used in traditional medicine, food products, and cosmetics. In China, only Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat. and Glycyrrhiza glabra L. are officially used and are usually processed with honey prior to use. To maintain the quality of commercially available herbal products, a simple, rapid, and reliable ultra high performance liquid chromatography with triple quadrupole mass spectrometry was developed to investigate the major active constituents of commercially available licorice products. Nineteen components were accurately determined, including eight triterpenoid saponins, one triterpene, and ten flavonoids. Subsequently, multivariate statistical analysis methods were employed to further explore and interpret the experimental data. The results indicated that liquiritin apioside may be considered as a candidate index for the quality control of licorice as well as 18β‐glycyrrhizic acid and liquiritin. In addition, both 18β‐glycyrrhizic acid and licorice‐saponin G2 can be used for discrimination between crude and honey‐processed licorice. Furthermore, using 18β‐glycyrrhizic acid and liquiritin as markers, this work revealed that the quality of licorice products may have declined in recent years. This highlights the need for additional effort focused on good agricultural practice during the processing of licorice. In summary, this study provides a valuable reference for the quality assessment of licorice.     

A novel method for quality consistency evaluation of Glycyrrhiza formula granules based on a spectrum-effect study

Quality consistency of Glycyrrhiza formula granules is essential for guaranteeing clinical efficacy. However, a suitable method to accurately and conveniently evaluate the consistency of the clinical efficacy of Glycyrrhiza formula granules is currently not available. This study established a method for the simultaneous determination of 12 active components in Glycyrrhiza formula granules using ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry. The rate of inhibition of cyclooxygenase-2 by different batches of Glycyrrhiza formula granules was determined. Near-infrared spectra were collected for different batches of Glycyrrhiza formula granules to detect their biological activity in the inhibition of cyclooxygenase-2. The quality consistency of the 11 batches of Glycyrrhiza formula granules was evaluated using principal component and correlation analyses. The results showed significant differences in the formula granules of Glycyrrhiza uralensis produced by the different manufacturers. Some differences were also observed among batches of formula granules produced by the same manufacturer. Correlation analysis of the chemical components and cyclooxygenase-2 activity showed that glycyrrhizic acid, liquiritin, and isoliquiritin were the main active components of Glycyrrhiza. Correlation analysis of the near-infrared spectra and cyclooxygenase-2 inhibition activity showed a high correlation between the active components and three characteristic bands: 3383–3995, 4227–4651, and 5315–5878 cm⁻¹. In this study, the main active anti-inflammatory components of Glycyrrhiza granules were screened. Thus, the near-infrared spectrum and characteristic active band of multi-index active components can be used to quickly detect the quality consistency of Glycyrrhiza formula granules, thereby improving the ability to control the quality and consistency of these granules.     

Fingerprint analysis and multi‐ingredient quantitative analysis for quality evaluation of Xiaoyanlidan tablets by ultra high performance liquid chromatography with diode array detection

A rapid and sensitive ultra high performance liquid chromatography method with diode array detection was developed for the fingerprint analysis and simultaneous determination of seven active compounds in Xiaoyanlidan (XYLD) tablets. The chromatographic separations were obtained on an Agilent Eclipse plus C₁₈ column (50 × 2.1 mm id, 1.8 μm) using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. Within 63 min, 36 peaks could be selected as the common peaks for fingerprint analysis to evaluate the similarities among several samples of XYLD tablets collected from different manufacturers. In quantitative analysis, seven compounds showed good regression (R > 0.9990) within test ranges and the recovery of the method was within the range of 95.9–104.3%. The method was successfully applied to the simultaneous determination of seven compounds in six batches of XYLD tablets. These results demonstrate that the combination of chromatographic fingerprint analysis and simultaneous multi‐ingredient quantification using the ultra high performance liquid chromatography method with diode array detection offers a rapid, efficient, and reliable approach for quality evaluation of XYLD tablets.     

Screening of analgesic and anti‐inflammatory active component in Fructus Alpiniae zerumbet based on spectrum–effect relationship and GC–MS

Fructus Alpiniae zerumbet is widely used in Guizhou province as a miao folk herb with anti‐inflammatory, analgesic, protection against cardiovascular diseases, antihypertension and antioxidant activities. To further investigate the chemical material basis, the spectrum–effect relationship was established using gray relational analysis between the chromatographic fingerprint and its bioactivities. Herein, the fingerprints of essential oils from Fructus Alpiniae zerumbet (EOFAZ) from various sources were determined by gas chromatography mass spectrometry, and the analgesic and anti‐inflammatory bioactivities were investigated using the mouse model of acetic acid‐induced writhing test and dimethylbenzene‐induced mouse ear edema test. Finally, 17 common peaks were identified from nine batches of A. zerumbet, by comparison with the standard mass spectra in Nist2005, Wiley275 library. Meanwhile, the results showed significant analgesic and anti‐inflammatory effects in all of the different sources of EOFAZ. In particularly, peak 1 (α‐pipene), peak 3 (β‐pinene), peak 9 (camphor) and peak 16 (α‐cadinol) might be the main bioactive ingredients for analgesic and anti‐inflammatory activities. The model of the spectrum–effect relationships of EOFAZ was successfully discovered, which provided a novel platform for finding the bioactive components, a theoretical foundation for its further study and helping to establish quality control of Fructus A. zerumbet.     

Comparison of the origin and phenolic contents of Lycium ruthenicum Murr. by high‐performance liquid chromatography fingerprinting combined with quadrupole time‐of‐flight mass spectrometry and chemometrics

The fruits of Lycium ruthenicum Murr. have long been used in folk medicine. Nevertheless, detailed information related to its phenolic composition and its quality control remains scarce. In this study, a simple and reproducible method, based on high‐performance liquid chromatography combined with chemometrics, was developed to authenticate 18 samples of L. ruthenicum Murr. collected from different parts of China through fingerprint analysis. The main peaks were identified by quadrupole time‐of‐flight electrospray ionization mass spectrometry. Four phenolics were quantified, and the most abundant phenolic compound in almost all samples was kukoamine A. Hierarchical cluster analysis and principal component analysis were applied to classify these samples. Also, a total of 26 compounds, which were mainly phenolic compounds and anthocyanins, were identified or tentatively identified based on the available literature and standard references. Among these, 16 were reported for the first time in the extract. The results showed that there was no significant difference between L. ruthenicum fruits from different provinces in terms of chemical composition. Also, the fingerprint together with chemometric analyses and quadrupole time‐of‐flight electrospray ionization mass spectrometry are promising methods for evaluating the quality consistency, identification, and comprehensive evaluation of L. ruthenicum .     

Determination of terbinafine in human plasma using UPLC–MS/MS: Application to a bioequivalence study in healthy subjects

A high‐throughput and sensitive ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method has been developed for the determination of terbinafine in human plasma. The method employed liquid–liquid extraction of terbinafine and terbinafine‐d7 (used as internal standard) from 100 μL human plasma with ethyl acetate–n‐hexane (80:20, v/v) solvent mixture. Chromatography was performed on a BEH C₁₈ (50 × 2.1 mm, 1.7 μm) column using acetonitrile–8.0 mm ammonium formate, pH 3.5 (85:15, v/v) under isocratic elution. For quantitative analysis, MS/MS ion transitions were monitored at m/z 292.2/141.1 and m/z 299.1/148.2 for terbinafine and terbinafine‐d7, respectively, using electrospray ionization in the positive mode. The method was validated according to regulatory guidance for selectivity, sensitivity, linearity, recovery, matrix effect, stability, dilution reliability and ruggedness with acceptable accuracy and precision. The method shows good linearity over the tested concentration range from 1.00 to 2000 ng/mL (r² ≥ 0.9984). The intra‐batch and inter‐batch precision (CV) was 1.8–3.2 and 2.1–4.5%, respectively. The method was successfully applied to a bioequivalence study with 250 mg terbinafine in 32 healthy subjects. The major advantage of this method includes higher sensitivity, small plasma volume for processing and a short analysis time.     

Chemical interaction between Paeonia lactiflora and Glycyrrhiza uralensis,the components of Jakyakgamcho‐tang,using a validated high‐performance liquid chromatography method: Herbal combination and chemical interaction in a decoction

The herbal combination is the basic unit of a herbal formula that affects the chemical characteristics of individual herbs. In the present study, a method of simultaneous determination of the 11 marker compounds in Jakyakgamcho‐tang was developed using high‐performance liquid chromatography with photodiode array detection. The validated analytical method was successfully applied to approach the chemical interaction between Paeonia lactiflora and Glycyrrhiza uralensis in co‐decoction. In P. lactiflora, the contents of gallic acid, oxypaeoniflorin, (+)‐catechin, paeoniflorin, and benzoylpaeoniflorin were decreased, while those of albiflorin and benzoic acid were increased; in G. uralensis, the contents of liquiritin, isoliquiritin, ononin, and glycyrrhizin were decreased, when decocting two herbs together. Moreover, as the ratio between P. lactiflora and G. uralensis was increased, the contents of chemical contents from each herb were proportionally increased. However, each content of marker compound per the gram of herbal medicine was decreased as the ratio of combinative herbs increased. The results showed that P. lactiflora and G. uralensis affect the extraction efficiency of chemical compounds in a Jakyakgamcho‐tang decoction. Overall, the method established in this study was simple, rapid, and accurate, and would be useful for the determination of marker compounds and for the investigation of the chemical interaction between herbal medicines.     

Development of a method using high‐performance liquid chromatographic fingerprint and multi‐ingredients quantitative analysis for the quality control of Yangxinshi Pian

A simple and reliable method of high‐performance liquid chromatography with diode array detection method was developed for fingerprint analysis and simultaneous determination of six compounds including puerarin, salvianolic acid B, berberine hydrochloride, palmatine chloride, dehydrocorydaline, and icariin in the Chinese medicine preparation Yangxinshi Pian. The separation was performed on an Agilent Eclipse XDB‐C₁₈ reserved‐phase column (250 mm × 4.6mm I.D., 5 μm) using gradient elution with 50 mmol/L monopotassium phosphate aqueous solution and methanol as mobile phase at a flow rate of 1.0 mL/min. The column operating temperature was set at 30°C, and the detection wavelength was 280 nm. The method was validated by linearity, precision, accuracy, stability, and recovery. For fingerprint analysis, 25 peaks were selected as the common peaks, and four kinds of similarities including cosine similarity (S), ratio of similarity (S′), projection content similarity (C), and content similarity (P) were applied to evaluate the quality consistency of different batches of Yangxinshi Pian. The results showed that the developed method was an efficient tool for quality evaluation of Yangxinshi Pian.     

Simultaneous quantification of multiple licorice flavonoids in rat plasma

Flavonoids are important naturally occurring polyphenols with antioxidant properties. In this study, we report the development of a liquid chromatography tandem mass spectrometry (LC-MS/MS)-based method capable of simultaneously quantifying multiple active licorice flavonoids (including liquiritin apioside, liquiritin, liquiritigenin, isoliquiritin apioside, isoliquiritin, and isoliquiritigenin) in plasma. Electrospray ionization was used to efficiently generate precursor deprotonated molecules of all the analytes and the [M-H]- ions were used to produce characteristic product ions for MS/MS analysis. We found that inclusion of a very low concentration of HCOONH4 (0.01 per thousand) in the LC mobile phase dramatically improved the detection limit for the tested flavonoids and decreased the interference by matrix effects, which have been referred to as "LC-electrolyte effects." Liquid-liquid extraction with ethyl acetate was effective for isolation of all the analytes and resulted in the lowest matrix effects of several tested sample cleanup methods. This bioanalytical method showed good linearity between 0.32 ng/mL and 1 microg/mL analyte in 50-microL plasma samples. The accuracy and precision at different analyte concentrations varied from 85 to 110% and from 0.8 to 8.8%, respectively. Finally, we demonstrated the applicability of this method in a pilot pharmacokinetic study of rats receiving an oral dose of Xiaochaihu-tang, an important Chinese herbal remedy for chronic hepatitis. The use of a low concentration of HCOONH4 in the LC mobile phase could be used to improve LC-mass spectroscopy- or LC-MS/MS-based methods.     

Simultaneous quantitative determination of 13 active components in the traditional Chinese medicinal preparation Suanzaoren oral liquid by HPLC coupled with diode array detection and evaporative light scattering detection

To control the quality of different forms of Suanzaoren decoction, an effective and reliable method for the simultaneous determination of 13 major components (neomangiferin, mangiferin, spinosin, liquiritin apioside, liquiritin, 6′′′‐feruloylspinosin, senkyunolide I, timosaponin BII, isoliquiritoside, timosaponin C, jujuboside A, jujuboside B, and timosaponin AIII) was developed and validated for the first time in this study using high‐performance liquid chromatography with diode array detection and evaporative light scattering detection. The chromatographic separation was performed on a Venusil MP C₁₈ column (250 mm × 4.6 mm, 5 μm) at 30°C with a gradient of acetonitrile/redistilled water as the mobile phase. Diode array detection was carried out at a wavelength of 275 nm. The drift tube temperature and the nitrogen gas flow rate of the evaporative light scattering detection were set at 50°C and 1.6 L/min, respectively. The newly developed method was successfully applied to the determination of 13 components in lab‐prepared Suanzaoren oral liquid, Suanzaoren mixture, and clinical Suanzaoren granules, and this study showed that this was a useful way to comprehensively evaluate the quality of Suanzaoren decoction in different forms of the preparation.