Comparison of ultra high performance supercritical fluid chromatography,ultra high performance liquid chromatography,and gas chromatography for the separation of synthetic cathinones

A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite‐5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended.     

Analysis of therapeutic proteins and peptides using multiangle light scattering coupled to ultra high performance liquid chromatography

Analysis of the physical properties of biotherapeutic proteins is crucial throughout all the stages of their lifecycle. Herein, we used size‐exclusion ultra high performance liquid chromatography coupled to multiangle light scattering and refractive index detection systems to determine the molar mass, mass‐average molar mass, molar‐mass dispersity and hydrodynamic radius of two monoclonal antibodies (rituximab and trastuzumab), a fusion protein (etanercept), and a synthetic copolymer (glatiramer acetate) employed as models. A customized instrument configuration was set to diminish band‐broadening effects and enhance sensitivity throughout detectors. The customized configuration showed a performance improvement with respect to the high‐performance liquid chromatography standard configuration, as observed by a 3 h column conditioning and a higher resolution analysis in 20 min. Analysis of the two monoclonal antibodies showed averaged values of 148.0 kDa for mass‐average molar mass and 5.4 nm for hydrodynamic radius, whereas for etanercept these values were 124.2 kDa and 6.9 nm, respectively. Molar‐mass dispersity was 1.000 on average for these proteins. Regarding glatiramer acetate, a molar mass range from 3 to 45 kDa and a molar‐mass dispersity of 1.304 were consistent with its intrinsic peptide diversity, and its mass‐average molar mass was 10.4 kDa. Overall, this method demonstrated an accurate determination of molar mass, overcoming the difficulties of size‐exclusion chromatography.     

Rapid determination of quinolones in cosmetic products by ultra high performance liquid chromatography with tandem mass spectrometry

This study developed an improved analytical method for the simultaneous quantification of 13 quinolones in cosmetics by ultra high performance liquid chromatography combined with ESI triple quadrupole MS/MS under the multiple reaction monitoring mode. The analytes were extracted and purified by using an SPE cartridge. The limits of quantification ranged from 0.03 to 3.02 μg/kg. The precision for determining the quinolones was <19.39%. The proposed method was successfully developed for the determination of quinolones in real cosmetic samples.     

Direct separation and detection of biogenic amines by ion-pair liquid chromatography with chemiluminescent nitrogen detector

Analysis of biogenic amines is critical to pharmaceutical and food industry due to their biological importance. For many years, the determination of biogenic amines has relied on high performance liquid chromatography (HPLC) coupling with pre-, on-, or post-column derivatization procedures to enable UV or fluorescent detections. In this study, 14 biogenic amines were separated on a Phenomenex Luna Phenyl-Hexyl column by an ion-pair liquid chromatography method using perfluorocarboxylic acids as ion-pair reagents and detected by a chemiluminescent nitrogen detector (CLND). This direct separation and detection HPLC method eliminated the time consuming and cumbersome derivatization procedures. Compared with HPLC-UV (post-column derivatization with ninhydrin) and HPLC-charged aerosol detector (CAD) methods, this HPLC-CLND technique provided narrower peaks, better baselines, and improved separations and detections. Excellent linearity was acquired by CLND for each of the 14 biogenic amines ranging from less than 1 ng to about 1000 ng (on-column weights). The relative response factors determined by this LC-CLND method were proportional to the numbers of nitrogen atoms in each compound, which has been the characteristic of the equimolar determinations by CLND. In addition, a number of samples including beer, dairy beverage, herb tea, and vinegar were analyzed by the LC-CLND method with satisfactory precision and accuracy.     

超高压液相色谱-飞行时间质谱法测定食品中19种非法染料

建立了同时测定食品中19种非法染料的方法。样品经丙酮/正己烷提取后,采用氧化铝柱层析净化,超高压液相色谱C18短柱分离,流动相用乙腈:0.1%甲酸溶液梯度淋洗,采用电喷雾离子源,在正离子模式下以飞行时间质谱检测,质量偏差小于1毫道尔顿。19种非法染料加标回收率在76%～108%,之间,方法的检测限为0.34～14μg/kg,精密度RSD在0.3%～12%之间。     

Universal response model for a corona charged aerosol detector

The universality of the response of the Corona Charged Aerosol Detector (CoronaCAD) has been investigated under flow-injection and gradient HPLC elution conditions. A three-dimensional model was developed which relates the CoronaCAD response to analyte concentration and the mobile phase composition used. The model was developed using the response of four probe analytes which displayed non-volatile behavior in the CoronaCAD and were soluble over a broad range of mobile phase compositions. The analyte concentrations ranged from 1μg/mL to 1mg/mL, and injection volumes corresponded to on-column amounts of 25ng to 25μg. Mobile phases used in the model were composed of 0-80% acetonitrile, mixed with complementary proportions of aqueous formic acid (0.1%, pH 2.6). An analyte set of 23 compounds possessing a wide range of physicochemical properties was selected for the purpose of evaluating the model. The predicted response was compared to the actual analyte response displayed by the detector and the efficacy of the model under flow-injection and gradient HPLC elution conditions was determined. The average error of the four analytes used to develop the model was 9.2% (n=176), while the errors under flow-injection and gradient HPLC elution conditions for the evaluation set of analytes were found to be 12.5% and 12.8%, respectively. Some analytes were excluded from the evaluation set due to considerations of volatility (boiling point <400°C), charge and excessive retention on the column leading to elution outside the eluent range covered by the model. The two-part response model can be used to describe the relationship between response and analyte concentration and also to offer a correction for the non-linear detector response obtained with gradient HPLC for analytes which conform to the model, to provide insight into the factors affecting the CoronaCAD response for different analytes, and also as a means for accurately determining the concentration of unknown compounds when individual standards are not available for calibration.     

Theoretical and experimental comparison of mobile phase consumption between ultra-high-performance liquid chromatography and high performance liquid chromatography

Ultra performance liquid chromatography (UPLC) using small particles and very high pressure has demonstrated higher resolution and speed compared with conventional HPLC. An additional benefit of UPLC is the significantly reduced consumption of mobile phase. This report discusses how column length, particle size, inner column diameter, extra column void volume, and capacity factor contribute to the reduction of mobile phase consumption in UPLC compared with HPLC. In addition, theoretical and experimental comparison of mobile phase consumption was made between isocratic HPLC and UPLC as well as between gradient HPLC and UPLC. Both theoretical and experimental results indicate that UPLC typically saves at least 80% of mobile phase in isocratic and gradient conditions when compared with HPLC.     

超高效液相色谱法检测化妆品中邻苯二甲酸酯

建立了测定化妆品中4种邻苯二甲酸酯-邻苯二甲酸二甲酯(DMP),邻苯二甲酸二乙酯(DEP),邻苯二甲酸二丁酯(DBP),和邻苯二甲酸二(2-乙基己基)酯(DEHP)-的分析方法。用超高效液相色谱(UPLC)带PDA检测器,色谱柱:Acquity UPLCTMBEHC C18(50 mm×2.1 mmi.d.,1.7μm)。样品经乙腈提取后,用UPLC-PDA进行分析检测,结合保留时间和光谱进行定性分析,定量检测波长224nm。该法的回收率为94.3%~98.7%,精密度RSD为0.9%~2.6%,以10倍噪声计,DMP、DEP、DBP和DEHP的检出限分别为0.14、0.21、0.21、0.31ng。用该分析方法对115件化妆品样品进行了分析检测,29件化妆品检出DEP,14件DBP,25件DEHP。总检出阳性样品54件,总阳性检出率47.0%。其检出质量分数:2.5~4348.2μg/g。该方法分离效果好,灵敏度高,能够满足检测化妆品中4种邻苯二甲酸酯的需要。     

Control of impurities in l-aspartic acid and l-alanine by high-performance liquid chromatography coupled with a corona charged aerosol detector

In this study a reversed phase ion-pair high-performance liquid chromatography (HPLC) method using charged aerosol detection (CAD) was developed and fully validated for the pharmaceutical quality control of l-aspartic acid (Asp). With a slight modification, the method also allows the evaluation of related substances in l-alanine (Ala). The method enables simultaneous control of related amino acids and of possibly occurring organic acids contaminants. A minimum limit of quantification of 0.03% could be achieved for all occurring related substances. Moreover, the detector sensitivity of the CAD was compared with an evaporative light scattering detector (ELSD). Depending on the analyte the CAD was found to be 3.6–42 times more sensitive than the ELSD. The HPLC method was applied to the purity testing of 8 samples of pharmaceutical grade and reagent grade Asp and of 12 samples of Ala supplied by various manufacturers. Both substances were found to be of high purity (greater than 99.8% for Asp and greater than 99.9% for Ala). Malic acid and Ala were the major impurities in Asp. Asp and glutamic acid (Glu) were the only detectable impurities in Ala.     

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.     

A reversed-phase high performance liquid chromatography coupled with resonance Rayleigh scattering detection for the determination of four tetracycline antibiotics

A new reversed-phase high performance liquid chromatography with resonance Rayleigh scattering detection (HPLC-RRS) was developed for simultaneous separation and determination of four tetracycline antibiotics (TCs). A good chromatographic separation among the compounds was achieved using a Synergi Fusion-RP column (150 mm × 4.6 mm; 4 μm) and a mobile phase consisting of methanol-acetonitrile-oxalic acid (5 mM) at the flow rate of 0.8 mL min⁻¹. Column temperature was 30 °C. The RRS signal was detected at λ_ex = λ_em = 370 nm. The recoveries of sample added standard ranged from 95.3% to 103.5%, and the relative standard deviation was below 2.79%. A detection limit of 2.12-5.12 μg mL⁻¹ was reached and a linear range was found between peak height and concentration in the range of 10.36-518.0 μg mL⁻¹ for oxytetracycline (OTC), 12.11-605.5 μg mL⁻¹ for tetracycline (TC), 11.79-589.5 μg mL⁻¹ for chlortetracycline (CTC) and 10.32-516.0 μg mL⁻¹ for doxycycline (DC). The linear regression coefficients were all above 0.999. The method has been applied successfully to the determination of OTC, TC, CTC, DC in pharmaceutical formulations and in honey. The method was simple, rapid and showed a better linear relation and high repeatability.     

Simultaneous determination of positive and negative pharmaceutical counterions using mixed-mode chromatography coupled with charged aerosol detector

A mixed-mode chromatography coupled with charged aerosol detector (CAD) method was developed in this work to simultaneously determine pharmaceutical counterions including both inorganic ions and organic ions in the forms of cations and anions. 25 commonly used pharmaceutical ions were studied and simultaneously separated within 20 min by this single method. A silica based mixed-mode column with reversed-phase/cation-exchange/anion-exchange modes was used. It provides reversed-phase, strong cation-exchange and weak anion-exchange properties at the same time. It also provides the HILIC behavior at high percentage of organic solvent. The effects of mobile-phase organic strength, buffer ions, ionic strength, pH and column temperature have been investigated to optimize the method as well as to understand the retention and separation mechanisms. Conventional HPLC system was used and no special chromatography system is needed. The presented method has been employed successfully for screening and quantitative analysis of counterions, unknown ionic impurities and salts in active pharmaceutical ingredients and in process control samples with excellent accuracy, precision and sensitivity. This method provides a simple, fast and generic approach to speed up pharmaceutical research and development process and enhance lab efficiency. The similar methodologies can be applied to other ion analysis.     

Simultaneous determination and pharmacokinetics of four triterpenoids by ultra high performance liquid chromatography with tandem mass spectrometry after the oral administration of Acanthopanax sessiliflorus (Rupr. et Maxim) Seem extract

A specific, simple, and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method utilizing the Triple Quad system has been developed and validated for the simultaneous determination and pharmacokinetic study of four triterpenoid components of Acanthopanax sessiliflorus in rat plasma. The components are 22‐α‐hydroxychiisanogenin, chiisanogenin, (1R,11α)1,4‐epoxy‐11‐hrdroxy‐3,4‐secolupane‐20(30)‐ene‐3,28‐dioic acid, and 22‐α‐hydroxychiisanoside. Sample preparation involved a liquid–liquid extraction of the analytes with ethyl acetate. Chromatographic separation was accomplished using an Agilent SB‐C₁₈ column (1.8 μm, 2.1 mm × 50 mm) with 2.0 min isocratic elution. The compounds were detected with a triple quadrupole tandem mass spectrometer in multiple reaction monitoring mode and an ESI source in negative mode. The method was linear for all analytes over the investigated range, with all determined correlation coefficients exceeding 0.9906. The limit of quantification of each analyte was lower than 1 ng/mL. The intraday and interday precisions were less than 14.9%, and the accuracy ranged from –10.2 to 11.8%. The mean recoveries of the analytes were higher than 80.0%, and the matrix effects were between 100.4 and 107.1%. These results may contribute to determining the mechanism of action and guiding the clinical application of Acanthopanax sessiliflorus.     

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.     

Simultaneous quantification of l‐tetrahydropalmatine and its urine metabolites by ultra high performance liquid chromatography with tandem mass spectrometry

l ‐tetrahydropalmatine (l ‐THP) is a tetrahydroprotoberberine isoquinoline alkaloid that has been used as an analgesic agent in China for more than 40 years. Recent studies indicated its potential application in the treatment of drug addiction. In this study, a sensitive and rapid method using ultra high performance liquid chromatography with MS/MS was developed and validated for simultaneous quantitation of l ‐THP and its desmethyl metabolites. Enzymatic hydrolysis was integrated into sample preparation to enable the quantitative determination of both free and conjugated metabolites. Chromatographic separation was achieved on an Agilent Poroshell 120 EC‐C₁₈ column. Detection was performed by MS in the positive ion ESI mode. The calibration curves of the analytes were linear (r² > 0.9936) over the concentration range of 1–1000 ng/mL with the lower limit of quantification at 1 ng/mL. The precision for both intra‐ and interday determinations was <8.97%, and the accuracy ranged from ?8.74 to 8.65%. The recovery for all the analytes was >70% without significant matrix effect. The method has been successfully applied to the urinary excretion study of l ‐THP in rats. The conjugates were found to be the major urine metabolites of the drug.     

A validated stability‐indicating ultra performance liquid chromatography method for the determination of potential process‐related impurities in eplerenone

A simple, sensitive, and accurate stability‐indicating analytical method has been developed and validated using ultra high performance liquid chromatography. The developed method is used to evaluate the related substances of eplerenone (EP). The degradation behavior of EP under stress conditions was determined, and the major degradants were identified by ultra high performance liquid chromatography with tandem mass spectrometry. The chromatographic conditions were optimized using an impurity‐spiked solution, and the samples, generated from forced degradation studies. The resolution of EP, its potential impurities, and its degradation products was performed on a Waters UPLC BEH C₁₈ column (50 × 2.1 mm, 1.7 μm) by linear gradient elution using a mobile phase consisting of 10 mmol/L ammonium acetate adjusted to pH 4.5, methanol and acetonitrile. A photo‐diode array detector set at 245 nm was used for detection. The flow rate was set at 0.3 mL/min. The procedure had good specificity, linearity (0.02–3.14 μg/mL), recovery (96.1–103.9%), limit of detection (0.01–0.02 μg/mL), limit of quantitation (0.03–0.05 μg/mL), and robustness. The correction factors of the process‐related substances were calculated.     

Simultaneous determination of antiviral drugs in chicken tissues by ultra high performance liquid chromatography with tandem mass spectrometry

An ultra high performance liquid chromatography with tandem mass spectrometry method was established for the rapid and simultaneous analysis of seven antiviral drugs, amantadine, rimantadine, memantine, moroxydine, imiquimod, oseltamivir, and acyclovir, in chicken liver, muscle, and egg. Homogenized samples were extracted with trichloroacetic acid and acetonitrile solutions and then purified by cation‐exchange solid‐phase extraction. The target drugs were analyzed by liquid chromatography with a UPLC BEH Amide column (2.1 mm × 100 mm, 1.7 μm) coupled with a tandem mass spectrometer operating in the positive multiple‐reaction mode. A perfectly linear relationship was obtained within the concentration ranges of 0.5–20 μg/L for acyclovir and 0.1–10 μg/L for the other six antiviral drugs. The average recoveries of the seven antiviral drugs using four addition levels in chicken liver, muscle, and eggs were 82.67–90.10, 82.30–92.27, and 81.98–93.77%, respectively, and the acceptable coefficients of variation were 5.18–9.88, 4.84–11.2, and 42.8–9.95%, respectively. The detection limits and detection capabilities of the analysis method for the seven antiviral drugs were in the ranges of 0.04–0.64 and 0.11–0.78 μg/kg, respectively. Additionally, an inter‐laboratory study among five laboratories further validated the method.     

Sensitive and rapid analytical method for the quantification of glucosamine in human plasma by ultra high performance liquid chromatography with tandem mass spectrometry

A highly sensitive and rapid ultra high performance liquid chromatography with tandem mass spectrometry method has been developed and validated for the determination of glucosamine in human plasma using miglitol as the internal standard. Special attention was paid to achieve the high throughput and sensitivity of the established method, and the absence of a matrix effect on the analytes. The sample preparation procedure involved a simple deproteinization step. The chromatographic separation was achieved on a Waters ACQUITY HSS Cyano column using a mixture of acetonitrile/2 mM ammonium acetate solution containing 0.03% formic acid (80:20, v/v) as the mobile phase with a very short run time of 1.5 min. This method was validated over the concentration range of 10–3000 ng/mL for glucosamine. The intra‐ and inter‐batch precision was <13.9% for the low, medium, and high quality control samples. The established method is highly sensitive with a lower limit of quantification of 10 ng/mL, low enough to determine the circadian rhythm on endogenous glucosamine level in human plasma, which has not been reported in detail until now. The method was successfully applied to characterize the pharmacokinetic profile of glucosamine in healthy volunteers following a single oral administration of 750 or 1500 mg glucosamine hydrochloride.     

Investigation of polar organic solvents compatible with Corona Charged Aerosol Detection and their use for the determination of sugars by hydrophilic interaction liquid chromatography

A range of organic solvents (ethanol, isopropanol and acetone) has been investigated as alternatives to acetonitrile and methanol when used in conjunction with Corona Charged Aerosol Detection (Corona CAD). These solvents have been evaluated with regard to their effect on the response of the Corona CAD. Three dimensional response surfaces were constructed using raw data showing the relationship between detector response, analyte concentration and percentage of organic solvent in the mobile phase, using sucralose or quinine as the test analyte. The detector response was non-linear in terms of analyte concentration for all solvents tested. However, detector response varied in an approximately linear manner with percentage of organic solvent over the range 0–40% for ethanol or isopropanol and 0–80% for acetone and methanol. The chromatographic performance of the various solvents when used as aqueous–organic mobile phases was evaluated for isocratic and gradient separations of sugars and sugar alcohols by hydrophilic interaction liquid chromatography (HILIC) using an Asahipak NH2P-504E column coupled with Corona CAD detection. It was found that whilst acetonitrile provided the highest column efficiencies and lowest detection limits of the solvents studied, acetone also performed well and could be used to resolve the same number of analytes as was possible with acetonitrile. Typical efficiencies and detection limits of 5330 plates m⁻¹ and 1.25 μg mL⁻¹, respectively, were achieved when acetone was used as the organic modifier. Acetone was utilised successfully as an organic modifier in the HILIC separation of carbohydrates in a beer sample and also for a partially digested dextran sample.     

Comparison of extraction solvents and sorbents in the quick,easy, cheap,effective, rugged,and safe method for the determination of pesticide multiresidue in fruits by ultra high performance liquid chromatography with tandem mass spectrometry

An improved analytical method was developed for the simultaneous quantification of several plant growth regulators and fungicides (carbendazim, pyrimethanil, metalaxyl, triadimefon, paclobutrazol, thiophanate, prochloraz, dimethomorph, difenoconazole, (4‐chlorophenoxy)‐acetic acid, (2,4‐dichlorophenoxy)‐acetic acid, thiadiazuron, forchlorfenuron and gibberellins) in fruits followed by ultra high performance liquid chromatography with tandem mass spectrometry. Samples were extracted and purified using a modified QuEChERS method. Different extraction solvents and sorbents in the QuEChERS method were compared. Optimum results were followed by the addition of 1% acetic acid in acetonitrile; C₁₈ sorbent was added due to the acidic nature of several pesticides. The recoveries of the pesticides were in the range 73.7–118.4%, with relative standard deviations lower than 16.63%. Limits of detection ranged from 0.1–1.0 μg/kg. The method presented here is simple, rapid, sensitive and can be applied to large‐scale monitoring programs to screen the presences of pesticides in fruits.