Simultaneous determination of five plant hormones in cotton leaves using QuEChERS combined with HPLC‒MS/MS

Background Plant hormones profoundly influence cotton growth,development,and responses to various stresses.Therefore,there is a pressing need for an efficient assay to quantify these hormones in cotton.In this groundbreaking study,we have established QuEChERS-HPLC‒MS/MS method,for the simultaneous detection of multiple plant hormones in cotton leaves,allowing the analysis and quantification of five key plant hormones.Results Sample extraction and purification employed 0.1%acetic acid in methanol and C18 for optimal recovery of plant hormones.The method applied to cotton demonstrated excellent linearity across a concentration range of 0.05–1 mg・L−1,with linear regression coefficients exceeding 0.99.The limits of quantification(LOQs)were 20μg・kg−1 for GA3 and 5μg・kg−1 for the other four plant hormones.Recovery rates for the five plant hormones matrix spiked at levels of 5,10,100,and 1000μg・kg−1 were in the range of 79.07%to 98.97%,with intraday relative standard deviations(RSDs)ranging from 2.11%to 8.47%.The method was successfully employed to analyze and quantify the five analytes in cotton leaves treated with plant growth regulators.Conclusion The study demonstrates that the method is well-suited for the determination of five plant hormones in cotton.It exhibits excellent selectivity and sensitivity in detecting field samples,thus serving as a robust tool for indepth research into cotton physiology.

Rapid Analysis of Four Alkaloids in Uncaria rhynchophylla by Core-Shell Column HPLC and Quantitative Analysis of Multi-Components by Single Marker(QAMS)

As a traditional herbal medicine,the major alkaloids in Uncaria rhynchophylla have been proven to have blood pressure-lowering and sedative effects.It is essential to develop an effective method for the determination of the major alkaloids in U.rhynchophylla.In this research,a rapid quantitative analysis involving multi-components analysis by a single marker strategy coupled with core-shell column HPLC was adopted to analyse four alkaloids(corynoxeine,isocorynoxeine,isorhynchophylline,rhynchophylline)in U.rhynchophylla.Isorhynchophylline was selected as the internal reference substance,the content of which was determined by the traditional external standard method.Relative correction factors(RCF)between isorhynchophylline and the other three alkaloids were calculated respectively.The results showed that the QAMS method had good robustness under different HPLC instruments.Nineteen batches of U.rhynchophylla were tested.No significant difference was observed between the results by QAMS and EMS(Correlation coefficient>0.99,p>0.05).The QAMS method could be employed as a rapid,effective technique for the quality control of U.rhynchophylla.

Evaluation of Uncertainty for Determination of Stevioside Content in Fermented Milk by HPLC

[Objectives]The paper was to establish an evaluation method for the uncertainty of stevioside(including stevioside,rebaudioside A,rebaudioside B,rebaudioside C,rebaudioside F,Dulcoside A,rubusoside and steviolbioside)content determination in fermented milk based on HPLC.[Methods]The mathematical model of stevioside content and the propagation rate of uncertainty were established,and the sources of uncertainty were analyzed.[Results]The uncertainty mainly came from four main aspects,including standard uncertainty u(C)introduced by solution concentration C,standard uncertainty u(V)introduced by sample volume V,standard uncertainty u(m)introduced by sample mass m weighing and standard uncertainty u(f_(rep))introduced by measurement repeatability of stevioside content after sample dissolution and constant volume.The uncertainty estimation table and fishbone chart of stevioside content X determination were established.The relative synthetic standard uncertainty of stevioside content was obtained,and the standard uncertainty was extended to form the measurement result of stevioside content and its uncertainty report.[Conclusions]The evaluation results can be directly applied to the daily practical detection work.

Validation of a Method for the Measurement of Caffeine in Water by HPLC-UV

For the production of a reference material from caffeine solution, one of the methods of characterization was HPLC-UV since caffeine is very sensitive to the UV. In this work, a batch solution of caffeine in water reference material of 1000 mg/kg has been gravimetrically prepared using a calibrated analytical balance. A sample of this solution was diluted to 25 mg/kg for measurement by HPLC-UV in the range 10 - 50 mg/kg. The chromatographic separation was carried out by C-18 column and a mobile phase assembled of 75% water and 25% methanol (v:v). The detection was made by the UV detector at 275 nm. The validation of this analytical method was carried out in accordance with requirements of the EURACHEM and ICH guidelines. The selectivity, linearity, accuracy, precision and trueness (recovery and bias) of the method were studied. The validation results proved that the method is fit-for-purpose of measuring the caffeine concentration in water in the range 10 - 50 mg/kg using HPLC-UV.

Silver-ion HPLC测定1,3-二油酸-2-棕榈酸三酰甘油的含量

准确测定1,3-二油酸-2-棕榈酸三酰甘油(OPO)的含量,建立了一种以高效液相色谱结合银离子交换柱(Silver-ion HPLC)的测定方法。以ChromSpher 5 Lipid(25 cm×4.6 mm,5μm)银离子交换柱通过HPLC正相系统分离三酰甘油,配合蒸发光散射检测器(ELSD),以毒性较小的二氯甲烷和丙酮为流动相。流速0.6 mL/min,柱温30℃。漂移管温度30℃,空气压力0.35 MPa。在此条件下,1,3-二油酸-2-棕榈酸三酰甘油和1,2-二油酸-3-棕榈酸三酰甘油两种同分异构体基本达到分离,样品出峰完整,峰形良好。OPO色谱峰面积的自然对数与浓度的自然对数呈良好的线性关系(R2=0.998 8)。用该方法测定了母乳脂肪、实验室合成结构油脂样品、商品结构油脂、棕榈油和山茶油中OPO的含量。结果表明该方法的灵敏度高、重现性良好。

替米沙坦血药浓度 HPLC 测定方法的研究

目的:建立替米沙坦血药浓度的高效液相-荧光色谱分析方法。方法:以依贝沙坦为内标,血浆样品用乙腈沉淀蛋白,色谱柱:Inersil ODS C_(18)色谱柱,(5μm,150mm×4.6mm),在线过滤器;流动相为水相(0.25%三乙胺水溶液)-乙腈(40∶60,v/v),20%磷酸调节pH为5.0;λ_(ex)=255nm,λ_(em)=390nm;流速1.0mL·min^(-1),柱温为25℃。结果:替米沙坦在6.25-3200ng·mL^(-1)的范围内有良好的线性关系(r=0.9998),最低检测浓度为1.25ng·mL^(-1)(S/N>3),该方法的相对回收率为99.7%-102.3%(n=5);绝对回收率为96.7%-105.3%(n=5);日内 RSD 为2.0%-5.9%,日间 RSD 为1.1%-6.2%。结论:本方法简便,准确,灵敏,特异性强,重现性好,可用于血浆中替米沙坦的测定及人体内药代动力学研究。

不同因子胁迫盐藻积累 β-胡萝卜素异构体的 HPLC 动态规律分析

本文采用ＨＰＬＣ技术研究了光强、温度、盐度三因子对盐藻积累β－胡萝卜素的动态协同胁迫作用．结果表明：它们存在着很强的协同胁迫作用，在温度２５℃，自然光照射时，２４０‰盐度积累β－胡萝卜素量大于１８０‰（０．７１６μｇ／ｍｌ＞０．３３７μｇ／ｍｌ），但在３２℃，光强１００００ｌｘ时，１８０‰盐度积累量大于２４０‰（（２．９４８μｇ／ｍｌ＞０．９８８μｇ／ｍｌ）；这一动态过程的时间曲线为“抛物”曲线；强胁迫条件有利于全反式异构体积累。

Ion-pairing HPLC methods to determine EDTA and DTPA in small molecule and biological pharmaceutical formulations

Ion-pairing high-performance liquid chromatography-ultraviolet （HPLC-UV） methods were developed to determine two commonly used chelating agents, ethylenediaminetetraacetic acid （EDTA） in Abilify （a small molecule drug with aripiprazole as the active pharmaceutical ingredient） oral solution and die- thylenetriaminepentaacetic acid （DTPA） in Yervoy （a monoclonal antibody drug with ipilimumab as the active pharmaceutical ingredient） intravenous formulation. Since the analytes, EDTA and DTPA, do not contain chromophores, transition metal ions （Cu2＋, Fe3＋） which generate highly stable metallocom- plexes with the chelating agents were added into the sample preparation to enhance UV detection. The use of metallocomplexes with ion-pairing chromatography provides the ability to achieve the desired sensitivity and selectivity in the development of the method. Specifically, the sample preparation in- volving metallocomplex formation allowed sensitive UV detection. Copper was utilized for the de- termination of EDTA and iron was utilized for the determination of DTPA. In the case of EDTA, a gradient mobile phase separated the components of the formulation from the analyte. In the method for DTPA, the active drug substance, ipilimumab, was eluted in the void. In addition, the optimization of the concentration of the ion-pairing reagent was discussed as a means of enhancing the retention of the aminopolycarboxylic acids （APCAs） including EDTA and DTPA and the specificity of the method. The analytical method development was designed based on the chromatographic properties of the analytes, the nature of the sample matrix and the intended purpose of the method. Validation data were presented for the two methods. Finally, both methods were successfully utilized in determining the fate of the chelates.

Authentication of Cassia seeds on the basis of two-wavelength HPLC fingerprinting with the use of chemometrics

High performance liquid chromatographic(HPLC) fingerprints of Cassia seed,a traditional Chinese medicine(TCM),were developed by means of the chromatograms at two wavelengths of 238 and 282 nm.Then,the two data sets were combined into one matrix.The application of principal component analysis(PCA) for this data matrix showed that the samples were clustered into four groups in accordance with the plant sources and preparation procedures.Furthermore,partial least squares(PLS),back propagation artificial neural...

Comparison of reversed-phase enantioselective HPLC methods for determining the enantiomeric purity of (S)-omeprazole in the presence of its related substances

A simple analytical high-performance liquid chromatography （HPLC） method was applied for the en- antiomeric excess determination of esomeprazole （（S）-OME）, the enantiopure active ingredient con- tained in drug products, in the presence of its potential organic impurities A-E. The enantioselective separation was accomplished on the immobilized-type Chiralpak ID-3 chiral stationary phase （CSP） under reversed-phase conditions. The results were evaluated and compared with those obtained by the official enantioselective method of European Pharmacopoeia used as the reference for checking the enantiomeric excess of （S）-OME. It has been established that the use of the Chiralpak ID-3 CSP allows the determination of the enantiomeric purity of （S）-OME without any interference coming from its chiral and achiral related substances. The analytical procedure of the drug regulatory agencies based on the AGP CSP suffered instead from poor specificity due to overlap of the peaks pertinent to the achiral impurity A and the chiral impurity （R）-OME （impurity F）.

Optimization of high pressure machine decocting process for Dachengqi Tang using HPLC fingerprints combined with the Box–Behnken experimental design

Using Dachengqi Tang（DCQT） as a model, high performance liquid chromatography（HPLC）fingerprints were applied to optimize machine extracting process with the Box–Behnken experimental design. HPLC fingerprints were carried out to investigate the chemical ingredients of DCQT; synthetic weighing method based on analytic hierarchy process（AHP） and criteria importance through intercriteria correlation（CRITIC） was performed to calculate synthetic scores of fingerprints; using the mark ingredients contents and synthetic scores as indicators, the Box–Behnken design was carried out to optimize the process parameters of machine decocting process under high pressure for DCQT. Results of optimal process showed that the herb materials were soaked for 45 min and extracted with 9 folds volume of water in the decocting machine under the temperature of 140 1C till the pressure arrived at 0.25 MPa;then hot decoction was excreted to soak Dahuang and Mangxiao for 5 min. Finally, obtained solutions were mixed, filtrated and packed. It concluded that HPLC fingerprints combined with the Box–Behnken experimental design could be used to optimize extracting process of traditional Chinese medicine（TCM）.

Application of HPLC and ESI-MS techniques in the analysis of phenolic acids and flavonoids from green leafy vegetables (GLVs)

Diets containing high proportions of fruits and vegetables reduce the risk of onset of chronic diseases. The role of herbal medicines in improving human health is gaining popularity over the years, which also increases the need for safety and efficiency of these products. Green leafy vegetables （GLVs） are the richest source of phenolic compounds with excellent antioxidant properties. Increased consumption of diets containing phenolic compounds may give positive and better results to human health and significantly improves the immune system. Highly selective, susceptible and versatile analytical techniques are necessary for extraction, identifica- tion, and quantification of phenolic compounds from plant extracts, which helps to utilize their important biological properties. Recent advances in the pre-treatment procedures, separation techniques and spectro- metry methods are used for qualitative and quantitative analysis of phenolic compounds. The online coupling of liquid chromatography with mass spectrometry （LC-MS） has become a useful tool in the metabolic profiling of plant samples. In this review, the separation and identification of phenolic acids and flavonoids from GLVs by LC-MS have been discussed along with the general extraction procedures and other sources of mass spectrometer used. The review is devoted to the understanding of the structural configuration, nature and accumulation pattern of phenolic acids and flavonoids in plants and to highlighting the recent developments in the chemical investigation of these compounds by chromatographic and spectroscopic techniques. It concludes with the advantages of the combination of these two methods and prospects.

QuEChERS HPLC-MS/MS法测定禽肉中9种喹诺酮类兽药残留量

建立Qu ECh ERS-液相色谱串联质谱法同时检测禽肉中的丹诺沙星、恩诺沙星、沙拉沙星、环丙沙星、氧氟沙星、诺氟沙星、依诺沙星、培氧沙星、双氟沙星9种喹诺酮类兽药残留量方法。样品以乙腈、EDTA-Mcllvaine和乙酸为提取试剂,无水硫酸钠为脱水剂,C18为吸附剂进行净化,以甲醇-0.1%甲酸水为流动相,反相C18色谱柱分离,正离子多反应监测模式进行质谱分析。9种喹诺酮在1.0μg/kg^200μg/kg范围内具有良好的线性关系,相关系数(r2)均在0.993以上。检出限范围为0.07μg/kg^0.20μg/kg,定量限范围在0.23μg/kg^0.67μg/kg之间。平均回收率介于70.8%~93.0%之间,相对标准偏(RSD)低于8.9%。该方法适合于检测禽肉中的喹诺酮类药物残留量的测定。

豚鼠脑在体微透析液氨基酸AccQ·Tag HPLC荧光测定法

目的建立柱前6-氨基喹啉基-N-羟基琥珀酰亚胺基氨基甲酸酯（AQC）衍生高效液相色谱（HPLC）脑在体微透析液中痕量氨基酸的检测方法。方法采用AQC为柱前衍生剂，氨基酸专用分析柱，二元梯度洗脱，荧光检测方法分析样品中的氨基酸。结果谊法对脑微透析液中17种氨基酸分离较好，相关系数为0．9025～0．9995，平均回收率为94．24％～98．34％，平均CV小于5％。在50min内可完成微透析液中17种氨基酸的测定。结论该方法稳定性好、敏感性和准确性较高，适用于豚鼠脑在体微透析液中痕量氨基酸水平的测定。

Determination of Paraquat in Human Serum by HPLC

目的：建立HPLC法测定人血清中百草枯含量。方法：色谱柱：Kromasil C18柱（200mm×4．6mm，5μm），流动相：乙腈-水（含0．03mol·L-1庚烷磺酸钠，0．24mol·L-1磷酸）=3：97（用三乙胺调pH至2．0）；检测波长258nm；柱温25℃；进样体积20μl；流速0．8ml·min-1。结果：百草枯在0．106—10．6mg·L-1浓度范围内线性关系良好（r=0．9993），最低检出浓度为0．065mg·L-1。高、中、低3种浓度样品绝对回收率〉89．4％，方法回收率〉94．4％，日内精密度RSD在0．12％～1．74％之间，日间精密度RSD在0．44％～2．89％之间。结论：该方法操作简便易行、灵敏度高、专属性强，适用于百草枯的人体血清浓度测定。

Single-run reversed-phase HPLC method for determining sertraline content,enantiomeric purity,and related substances in drug substance and finished product

A direct enantio-,diastereo-,and chemo-selective high-performance liquid chromatographic method was developed for determining the content,enantiomeric purity,and related substances of the chiral antidepressant drug sertraline HCl in a single chromatographic run.The separation was achieved on a chiral stationary phase based on amylose tris(3-chloro-5-methylphenylcarbamate)under reversed-phase conditions.The method was optimized by evaluating the influence of the temperature and mobile phase composition on the retention and selectivity.The application of the single-run approach allowed to baseline resolve all investigated species in less than 15 min,without using buffers or tandem-coupled columns.The chromatographic method was validated according to the guidelines of the Official Medicines Control Laboratory and applied to control the content of sertraline HCl and related chiral substances in a generic antidepressant formulation.

灭澳灵片中靛蓝与靛玉红的 HPLC 分析

采用 HPLC 法测定灭澳灵糖衣片中靛蓝与靛玉红含量,以甲醇-水(8:2)为流动相,CLC-ODS 为固定相,选用 VIS546nm 为检测波长。定量准确,效果满意。

Quantitation of metallothionein and cadmium in metallothionein in mink livers by anion-exchange HPLC-GFAAS method

Metallothionein (MT) has a great capacity of binding heavy metals showing an interesting connection with metal toxicology, as a biochemical marker for environmental metal pollution. Anino-exchange high per formance liquid chromatography (HPLC) was used to isolate and quantitate MT in livers of minks which were contaminated with heavy metals. MT isoforms (MT-I and MT-II) were eluted at approximately 11.3 and 14.3 min respectively from a DEAE-5 PW anion-exchange column with a Tris-HCl buffer (0.01 -0.25 mol/L, pH 8.6) and detected by UV absorbance at 254 nm. The cadmium concentrations in mink liver MT elutkms were determined by graphite furnace atomic absorption spectrometry (GFAAS) . Obvious increase in liver MT-I concentration rather than liver MT-II was found when the minks were contaminated by feeding contaminated fish captured from the heavy metal-polluted river. The cadmium concentration in mink liver MT-I also increased to some extent as the contaminated level increased.

PREPARATION AND EVALUATION OF HPLC BONDED PHASE WITH L-PROLINE LIGAND

This paper describes a simple method for the preparation of L-proline stationary phase bonded to silica gel and characterization of the bonded phase by IR spectrometry, elemental analysis and nitrogen adsorption method at low temperature.The enantiomeric resolutions of 3-(2-pyridyl)-3-aminopropionic acid and 2,3-diaminobutanoic acid on the bonded phase were carried out.

NON-AQUEOUS REVERSED PHASE HPLC WITH LOW-WAVELENGTH UV DETECTION FOR TRIGLYCERIDE ANALYSIS

Glycerides are first separated to classes of triglycerides(TGs), diglycerides(DGs) and monoglycerides(MGs) by normal phase HPLC on silica gel column. Individual triglyceride separation is then achieved by non-aqueous reversed phase(NARP) HPLC on C_(18) column with UV detection at 215nm.