Detection of trace components in Xiangdan injection of Dalbergia odorifera based on microextraction and back-extraction along with bar-form-diagram strategy.

Xiangdan Injection are commonly used traditional Chinese medicine formulations for the clinical treatment of cardiovascular diseases. However, the trace components of Dalbergia odorifera in Xiangdan Injection pose a challenge for evaluating its quality due to the difficulty of detection. This study proposes a technology combining dispersive liquid-liquid microextraction and back-extraction (DLLME-BE) along with Bar-Form-Diagram (BFD) to address this issue. The proposed combination method involves vortex-mixing tetradecane, which has a lower density than water, with the sample solution to facilitate the transfer of the target components. Subsequently, a new vortex-assisted liquid-liquid extraction step is performed to enrich the components of Dalbergia odorifera in acetonitrile. The sample analysis was performed on HPLC-DAD, and a clear overview of the chemical composition was obtained by integrating spectral and chromatographic information using BFD. The combination of BFD and CRITIC-TOPSIS strategies was used to optimize the process parameters of DLLME-BE. The determined optimal sample pre-treatment process parameters were as follows: 200 µL extraction solvent, 60 s extraction time, 50 µL back-extraction solvent, and 90 s back-extraction time. Based on the above strategy, a total of 29 trace components, including trans-nerolidol, were detected in the Xiangdan Injection. This combination technology provides valuable guidance for the enrichment analysis of trace components in traditional Chinese medicines.

Comprehensive study on the differential extraction and comparison of bioactive health potential of the Broccoli (Brassica oleracea).

Introduction: Broccoli is a cruciferous vegetable that has been shown to have numerous potential therapeutic benefits because of its bioactive compounds. Methods: In this study, we compared the bioactive efficacy of cooked and uncooked (fresh) stems and florets of broccoli extracted with three different solvents: acetonitrile, methanol, and aqueous extracts. The extraction yield and antioxidant and antibacterial potential of different broccoli extracts were examined. Results: Fresh and boiled floret stem extracts increased the extraction yield. The extraction yields were higher for the methanol and acetonitrile extracts than for the aqueous extracts. The antioxidant efficacy of the different extracts was studied using ABTS, DPPH, and metal ion reduction assays. The acetonitrile and aqueous extracts exhibited higher antioxidant activities than the methanolic extracts in different antioxidant assays. In addition, increased antioxidant activity was observed in fresh florets and boiled broccoli stems. TPC and TFC contents were higher in the methanolic extracts than in the aqueous extracts. Similar to antioxidant activities, anti-inflammatory activities were found to be higher in the acetonitrile and aqueous extracts, particularly in boiled stems and fresh florets. Broccoli extracts have been shown to be active against Bacillus subtilis and moderately effective against Pseudomonas aeruginosa and Staphylococcus aureus. Conclusions: Acetonitrile and aqueous extraction of broccoli might be an ideal choice for extraction methods, which show increased extraction yield and antioxidant and anti-inflammatory potentials. Utilization of phytomolecules from natural sources is a promising alternative approach to synthetic drug development.

A newly developed UPLC-MS/MS method for simultaneous quantitative analysis of ajuforrestin A, ajuforrestin B, ajugamacrin and 8-O-acetylharpagide derived from Ajuga plants in mice blood and the in vivo pharmacokinetics.

OBJECTIVE: To develop a sensitive and fast detection method via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to assess the concentration of ajuforrestin A, ajuforrestin B, ajugamacrin and 8-O-Acetylharpagide primarily derived from Ajuga plants in mice blood and their pharmacokinetics. METHODS: Single protein precipitation with high-proportioned acetonitrile is chosen for sample clean-up. The UPLC HSS T3 (2.1 mm × 100 mm, 1.8 µm) column with a mobile phase in gradient elution mode at the flow rate of 0.4 mL/min was used for sample separation. Acetonitrile was selected as the organic phase solution and water containing 0.1% formic acid was chosen as the aqueous solution. A tandem mass spectrometer containing an electrospray ionization (ESI) source in the positive ionization mode was used to detect four compounds via multiple reaction monitoring (MRM). RESULTS: The calibration curves (5-1000 ng/mL) of four compounds were linear with correlation coefficients > 0.997. The matrix effects, accuracy, precision, and recovery were all within permissible scope. CONCLUSIONS: In this approach, the corresponding pharmacokinetic parameters were successfully clarified in mouse for the first time, which provided a theoretical basis for the improvement of the standard of Ajuga plants and the safety of clinical medication. Furthermore, this method may provide the UPLC-MS/MS evidence for the differentiation of the main close relative varieties of genus Ajuga according to these plants contain different mixtures of the four marker compounds.

Development and validation of a deep eutectic solvent-assisted liquid-liquid extraction method for simultaneous quantification of six steroid hormones in serum by liquid chromatography-tandem mass spectrometry.

Steroid hormones have been reported to be associated with endocrine system diseases. This paper proposes a novel procedure of deep eutectic solvent (DES)-assisted liquid-liquid extraction (LLE) to extract six steroid hormones (including cortisone, cortisol, androstenedione, testosterone, 17-hydroxyprogesterone, and progesterone) from serum coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of five types of L-proline, choline chloride, and citric acid-based DESs were tailored; the DES from L-proline and ethylene glycol at a molar ratio of 1:4 with 20 % acetonitrile was selected as the best-fit assisted solvent for the six steroid hormones compared with other DESs. The parameters for extraction by selected DES were optimized using Box-Behnken design (BBD), and the optimal extraction conditions are 200 µL of acetonitrile, 100 µL of the sample, and 80 µL of DES. Under optimum conditions, the method has good linear calibration ranges (between 0.07 ng mL-1 and 600 ng mL-1), correlation coefficients of determination (r2>0.99), and low limits of quantification (between 0.02 and 0.60 ng mL-1). The extraction recoveries were in the range of 81.84-114.43 %, and the intra-day and inter-day relative standard deviations (RSDs) were less than 10 %.In general, the DES-LC-MS/MS method is a simple and environmentally-friendly method, which can be complementary to the presently available methods for determining steroid hormones in serum.

Greener production of a starch-based nanohybrid material (core-shell) for the simultaneous extraction of persistent organic pollutants in shrimp samples.

Here, a novel nanohybrid material (Ag@CD@ANS) based on oat starch was produced, characterized, and applied to extract persistent organic pollutants in a shrimp sample. By the characterization experiments, Ag@CD@ANS was successfully synthesized. The functionalization of the material by 1,2-naphthoquinone-4-sulphonic acid (ANS) was confirmed using the infrared technique and CHN elemental analysis. The isotherm study showed that the material has a high adsorption capacity for the pesticides of interest (flutriafol, atrazine, heptachlor, DDT and bifenthrin) allowing their extraction from shrimp samples. The optimal condition for extraction was obtained using multivariate analysis. The nature of the elution solvent (hexane, methanol, acetonitrile) and the mass ratio between sample:adsorbent (1:1; 1:5 and 1:10) were the evaluated factors for extraction using Ag@CD@ANS and commercial adsorbents (neutral alumina, octadecyl, silica gel). From the multivariate analysis, it was observed that the optimal condition for pesticide extraction using Ag@CD@ANS was reached, using a 1:5 ratio (sample:adsorbent) and acetonitrile (10 mL) as elution solvent. For the commercial adsorbents, the optimal condition for pesticide extraction was reached, using a 1:3 ratio (sample:adsorbent), acetonitrile (10 mL) and neutral alumina as commercial adsorbent. Ag@CD@ANS efficiency was compared with an optimal commercial adsorbent (neutral alumina). No significant difference (p < 0.05) between neutral alumina and Ag@CD@ANS was observed. Recoveries ranging from 75 to 105 % with coefficients of variation ≤ 15 % (n = 3) were obtained using neutral alumina while using Ag@CD@ANS, recoveries ranging from 73 to 102 %, with coefficient of variation ≤ 13 % (n = 3) were obtained for the target pesticides. Limits of detection ranging from 0.5 to 1.0 µg Kg-1 and limits of quantification ranging from 1.6 to 3.3 µg Kg-1 were reached. The results demonstrated that Ag@CD@ANS can alternatively be used as a support for the extraction of persistent organic pollutants, having the advantage of being reusable for up to three cycles.

Method validation for detection of afidopyropen and M440I007 in tea.

BACKGROUND: Afidopyropen is a novel biorational insecticide for controlling piercing pests with great potential for application in tea gardens that can form the metabolite M440I007 when utilized for crops. However, because of a lack of analytical method for afidopyropen and M440I007 in tea, there is no means of monitoring the residues. Therefore, method development, validation and simultaneous determination of afidopyropen and M440I007 in fresh tea leaves, dried tea and tea infusion is of prime significance. RESULTS: A TPT cartridge-based method was developed for the solid phase extraction of afidopyropen and M440I007 from tea matrices. Extraction and clean-up conditions, including the composition, volume and temperature of elutions, were optimized to achieve the best results. Both targets were extracted using water and acetonitrile, with a water:acetonitrile (v/v) ratio of 4:10 for fresh leaves and 8:10 for dried tea, which were then cleaned and analyzed using ultraperformance liquid chromatography-tandem mass spectrometry. Both analytes demonstrated excellent linearity with a correlation coefficient above 0.998. The optimized analytical method offered limits of quantifications of 0.005, 0.005 and 0.002 mg kg-1 (converted to dried tea) in fresh tea shoots, dried tea and tea infusion for both targets, respectively. Average recoveries of afidopyropen and M440I007 ranged from 79.0% to 101.5%, with relative standard deviations ≤ 14.7%. CONCLUSION: The results showed that the method of determination for these insecticides in tea matrices was practical and efficient. © 2023 Society of Chemical Industry.

[Analysis and evaluation on Paeoniae Radix Alba from different cultivars by UPLC-Q-TOF-MS and HPLC].

In this study, an established ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS) method was combined with multivariate statistical analysis to investigate the commonality and difference of main chemical components in the medicinal parts of Paeonia lactiflora from different cultivars; in addition, a high performance liquid chromatography(HPLC) method was established to simultaneously determine the content of eight active components in Paeoniae Radix Alba. Non-targeted analysis was carried out by UPLC-Q-TOF-MS on a Waters ACQUITY UPLC BEH C_(18)(2.1 mm×100 mm, 1.7 µm) column with a gradient elution of 0.1% aqueous formic acid(A)-acetonitrile(B) as the mobile phase at a flow rate of 0.2 mL·min~(-1). The column temperature was 30 ℃, and an electrospray ionization source was used to acquire mass spectrometry data in positive and negative ion modes. According to the accurate molecular weight and fragment ion information provided by multi-stage mass spectrometry and by comparison with reference substances and literature reports, thirty-six identical components were identified in Paeoniae Radix Alba from different cultivars with positive and negative ion modes. In the negative ion mode, two groups of samples were well separated; specifically, seventeen components with significant differences in content were screened and identified, and one component unique in "Bobaishao" was obtained. Quantitative analysis was conducted by high-performance liquid chromatography(HPLC) on an Agilent HC-C_(18)(4.6 mm×250 mm, 5 µm) column with a gradient elution of 0.1% aqueous phosphoric acid(A)-acetonitrile(B) as the mobile phase at a flow rate of 1.0 mL·min~(-1). The column temperature was 30 ℃ and the detection wavelength was at 230 nm. An HPLC method was developed for the simultaneous determination of eight active components(gallic acid, oxypaeoniflorin, catechin, albiflorin, paeoniflorin, galloylpaeoniflorin, 1,2,3,4,6-O-pentagalloylglucose, benzoyl-paeoniflorin) in Paeoniae Radix Albaa from different cultivars. Satisfactory linearity was achieved within the investigated linear ranges and with fine coefficients(r>0.999 0), and the methodological investigation showed that the method had good precision, repeatability and stability. The mean recoveries were 90.61% to 101.7% with RSD of 0.12% to 3.6%(n=6). UPLC-Q-OF-MS provided a rapid and efficient qualitative analytical method for the identification of the chemical components in Paeoniae Radix Alba, and the developed HPLC method was simple, rapid and accurate, which could provide a scientific basis for the evaluation of the germplasm resources and herbal quality of Paeoniae Radix Alba from different cultivars.

QuEChERS-Based Approach to the Extraction of Five Calcium Channel Blockers from Plasma Determined by UPLC-MS/MS.

Here, a QuEChERS (quick, easy, cheap, effective, rugged, and safe) pretreatment method was combined with UPLC-MS/MS to facilitate the rapid and reliable simultaneous detection of five calcium channel blockers (CCBs) in human plasma. For this approach, samples were treated with 1 mL of acetonitrile, 350 mg of magnesium sulfate, and 70 mg of PSA adsorbent prior to centrifugation. Supernatants then underwent gradient elution for 8 min with an Agilent C18 column using an acetonitrile-water solution supplemented with 5 mmol⋅L-1 of ammonium acetate. This technique exhibited a good linear response in the 1-800 ng⋅mL-1 range for the analyzed drugs, with an R2≥ 0.9921, an accuracy of 87.54-113.05%, a matrix effect (ME) of 91.21-116.39%, a precision of 0.19-11.64%, and stability of no more than 10.05%. This time-saving QuEChERS reagent-based pretreatment technique thus allowed for the simultaneous and accurate detection of five CCBs in human plasma samples, providing a promising new basis for therapeutic drug monitoring in patients with hypertension.

Simple and rapid method for 336 multiresidual pesticide analysis in saliva, determination of their chemical stabilities, and biomonitoring of farmers.

Simultaneous multiresidual pesticide analysis of saliva samples was performed using scaled-down QuEChERS extraction with LC-MS/MS and GC-MS/MS. The optimum extraction procedure using acidified acetonitrile was applicable to 336 pesticides (287 for LC-MS/MS and 49 for GC-MS/MS). To determine pesticide multiresidues in saliva, 100 µL of the sample was extracted with 200 µL of 0.1% formic acid in acetonitrile, and the initial extract was partitioned with 40 mg of MgSO4 and 10 mg of NaCl. The organic supernatants (120 µL) were then mixed with acetonitrile (30 µL) for matrix-matching (4:1, v/v), and the final extract solution was injected into the LC-MS/MS (4 µL) and GC-MS/MS (2 µL) systems. The established analytical method showed a good LOQs between 5 and 25 ng/mL with reliable accuracy/precision values and recovery results (50-140%) for the target pesticides. Under the two different storage conditions, most of the analytes did not undergo chemical changes in the saliva samples, whereas some pesticides were more stable in freeze-thaw processes than those left at room temperature. Biomonitoring of farmers (ten mixers and ten sprayers) was successfully applied using the validated method, and two carbamates (fenobucarb and propamocarb) were determined at trace concentrations (12.5-675.0 ng/mL from 11 positively detected samples).

Acyl-Nω-methylserotonins and Branched-chain Acylserotonins in Lemon and Other Citrus Seeds-New Lipids with Antioxidant Properties and Potential Pharmacological Applications.

We have found 15 previously unknown compounds in seeds of lemon and other citrus species, such as tangerine, grapefruit and pomelo. The structure of these compounds was characterized by HR-MS spectrometry, fluorescence spectroscopy and chemical synthesis. These compounds were predominantly long-chain (C20-C25), saturated acyl-Nω-methylserotonins with the main contribution of C22 and C24 homologues, usually accounting for about 40% and 30% of all acylserotonins, respectively. The other, previously undescribed, minor compounds were branched-chain acylserotonins, as well as normal-chain acylserotonins, recently found in baobab seed oil. Within the seed, acylserotonins were found nearly exclusively in the inner seed coat, where probably their biosynthesis proceeds. On the other hand, lemon seedlings contained only trace amounts of these compounds that were not found in adult leaves. The compounds identified in the present studies were shown to have antioxidant properties in vitro, using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. In the investigated reaction in hexane, Me-C22 and Me-C24-serotonins were less active than n-C22 and n-C24-serotonins and δ-tocopherol, while branched-chain acylserotonins (iso-C21 and -C25) showed higher antioxidant activity than all the normal-chain compounds. On the other hand, all these compounds showed a similar but considerably lower antioxidant activity in acetonitrile than in hexane.

Validated UPLC-MS/MS method for the analysis of vitamin B6 pyridoxal 5́-phosphate, pyridoxal, pyridoxine, pyridoxamine, and pyridoxic acid in human cerebrospinal fluid.

Vitamin B6 and its metabolites play a crucial role in the development and interaction of brain metabolism. Following diagnostic improvements additional inherited disorders in vitamin B6 metabolism have been identified, most of them leading to a severe epileptic disorder accompanied by progressive neurological deficits including intellectual disability and microcephaly. Since early treatment can improve the outcome, fast and reliable detection of metabolic biomarkers is important. Therefore, the analysis of vitamin B6 metabolites has become increasingly important, but is, however, still challenging and limited to a few specialized laboratories. Until today, vitamin B6 metabolites are measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) using trichloroacetic acid for protein precipitation. In this work, we present the development and validation of a new, accurate and reliable method for analysis and quantification of the vitamin B6 vitamers pyridoxal 5́-phosphate (PLP), pyridoxal (PL), pyridoxine (PN), pyridoxamine (PM) and pyridoxic acid (PA) in human CSF samples using acetonitrile for protein precipitation. The method is based on ultra-performance liquid chromatography-tandem mass spectrometry using electrospray ionization (UPLC-ESI-MS/MS). The calibration was performed in surrogate matrix Ringer solution and metabolites were quantified by their corresponding isotopically labelled internal standards. A protein precipitation by acetonitrile was applied greatly improving chromatographic separation of the metabolites in a 4.7 min chromatographic run. The method was validated following the European Medical Agency (EMA) and Food and Drug Administration (FDA) guidelines for bioanalytical method validation. The metabolites were quantified from 5 to 200 nmol/L with a seven-point calibration curve and minimum coefficient of regression of 0.99. The validation was performed with quality control samples at four concentration levels with surrogate matrix ringer solution and pooled CSF material. Within- and inter-day accuracy and precision in Ringer solution were within 85.4 % (PLP) and 114.5 % (PM) and from 2.6 % (PA) to 16.5 % (PLP). Within- and inter-day accuracy and precision in pooled CSF material were within 90.5 % (PN) and 120.1 % (PL) and from 1.7 % (PA) to 19.0 % (PM). The method was tested by measuring of 158 CSF samples to determine reference ranges. The B6 vitamers PLP and PL were determined in all CSF samples above 5 nmol/L while PN, PM and PA showed concentrations below or near LOQ. Probable supplementation of PLP was detected in eight CSF samples, which revealed high concentrations of PM, PN, PL, or PA, whereas PLP was in the reference range or slightly elevated. The method is suitable for the application within a routine diagnostic laboratory.

Pharmacokinetics of Herb-Drug Interactions of Plumbagin and Tazemetostat in Rats by UPLC-MS/MS.

Objective: A sensitive and rapid UPLC-MS/MS method for determination of tazemetostat in rat plasma was developed, and the pharmacokinetics of herb-drug interactions (HDIs) of plumbagin (PLB) and tazemetostat was investigated. Methods: After the rat plasma samples were precipitated by acetonitrile, tazemetostat and verubecestat (ISTD) were detected. Gradient elution was performed with 0.1% formic acid and acetonitrile as mobile phases. The multi-reaction monitoring was used with ESI+ source, and the ion pairs for tazemetostat and ISTD were m/z 573.12→135.99 and m/z 410.10→124.00, respectively. 12 SD rats were randomly divided into the control group and the experimental group, 6 rats in each group. The rats in the experimental group were given PLB 100 mg/kg by gavage once a day for 7 consecutive days. The rats in the control group were given the same amount of 0.1% sodium carboxymethyl cellulose solution by gavage once a day for 7 consecutive days. At the seventh day, tazemetostat (80 mg/kg) was given and the blood was collected at different time points. The main parameters of pharmacokinetics were calculated and the herb-drug interactions (HDIs) were evaluated. Results: In the calibrated range of 1-1000 ng/mL, tazemetostat had a good linearity. The extraction recovery was more than 84%, and the RSD of intra-batch and inter-batch precision were both less than 15%. The Cmax of tazemetostat in the experimental group was 32.48% higher than that in the control group, and the AUC(0-t) and AUC(0-∞) of tazemetostat in the experimental group were 46.24% and 46.67% higher than that in the control group, respectively, and the t1/2 was prolonged from 10.56 h to 11.73 h. Conclusion: A simple, rapid and sensitive UPLC-MS/MS method for the determination of tazemetostat in rat plasma was established. PLB can inhibit the metabolism of tazemetostat and increase the plasma exposure of tazemetostat in rats.

Isolation of lanosterol and dihydrolanosterol from the unsaponifiable matter of lanolin by urea complexation and countercurrent chromatography in heart-cut recycling mode.

4,4-Dimethyl-substituted sterols are bioactive minor sterols of most animal fats and plant oils, but higher shares are present in lanolin (wool grease). Here, the isolation of the 4,4-dimethyl-substituted sterols dihydrolanosterol and lanosterol from lanolin by countercurrent chromatography (CCC) is described. An initial examination of the hexane extract of saponified lanolin showed the presence of relatively high portions of fatty alcohols which were known to co-elute with the target analytes in CCC. Hence, fatty alcohols were precipitated by urea complexation. Unexpectedly, 4,4-dimethyl-substituted sterols were also found in the crystalline fraction, while cholesterol and other desmethylsterols were detected in the liquid phase. Urea complexation represented a useful preparative method for the separation of desmethylsterols and 4,4-dimethyl-substituted sterols from lanolin. Shake flask experiments of 4,4-dimethyl-substituted sterols and fatty alcohols with 14 biphasic solvent systems indicated suitable partition coefficients (K values) with n-hexane/ethanol/water (12:8:1, v/v/v) and n-hexane/benzotrifluoride/acetonitrile (20:7:13, v/v/v). After initial tests with conventional CCC, the application of CCC in heart-cut recycling mode provided 4,4-dimethyl-substituted sterols with purities of 99 % (dihydrolanosterol) and 95 % (lanosterol).

Quantification of rosmarinic acid from different plant species of lower Himalayan region and expression analysis of underlying L-Phenylalanine pathway.

This study adopts a very effective high-performance liquid chromatography (HPLC) technique for the quantitative determination of rosmarinic acid (RA) and PCR-based amplification of biosynthetic key regulators in Isodon rugosus, Daphne mucronata, and Viburnum grandiflorum from the lower Himalayan regions. Rosmarinic acid is engaged in a variety of biological processes and has significant industrial significance. In this study, it was identified from crude methanolic extract using thin-layer chromatography with a standard, and its content was quantified using HPLC without interrupting spikes using a mixture of methanol and deionized water containing acetonitrile (70:30 v/v) and acetic acid (0.1% v/v) at UV 310 nm absorption. We used RT-PCR to identify cDNAs encoding PAL, C4H, and RAS, and Image J's semi-quantitative analysis to quantify the expression levels of genes involved in RA production from chosen plant material. The highest levels of PAL, C4H, and RAS were detected, by band intensity, in the leaves and flowers of I. rugosus, which also exhibited a substantial quantity of RA. However, in V. grandiflorum and D. mucronata the transcript of the given genes was low. The concentration of RA ranged from 187.7 to 21.2 mg g-1 for I. rugosus, 17.42 to 5.42 mg g-1 for V. grandiflorum, and 15.19 mg g-1 for D. mucronata. This study demonstrated that the method for quantifying RA from a crude methanolic extract was effective, indicating that I. rugosus might be used as an indigenous alternative source of RA.

Green and Efficient Determination of Fluoroquinolone Residues in Edible Green Fruits and Leafy Vegetables by Ultrasound-Assisted Extraction Followed by HPLC-MS/MS.

In this work, a simple, quick and efficient analytical method for determination of human and veterinary fluoroquinolone antimicrobial residues in lettuce, cucumber and spinach is developed. The procedure entails a 6 min ultrasound-assisted extraction (UAE, 3 × 2 min) in an alkaline (2% v/v NH3) aqueous solution containing Mg2+ ions (3 × 6 mL), with no need for organic solvents. The extract is submitted to cleanup on the HLB™ cartridge and the fluoroquinolones are separated and quantified by HPLC-MS/MS in a 10 min chromatographic run, using a small amount of acetonitrile in the mobile phase. The method, entirely developed in real matrices, is validated according to the updated analytical guidelines and provided suitable recoveries in the range of 67-116% and precision (RSD ≤ 20%, n = 3) at different concentrations (15, 70 and 150 ng g-1), with method quantification limits of 2-10 ng g-1. Fluoroquinolones were detected and quantified at concentrations from few to hundreds of nanograms per gram in vegetables from supermarkets, demonstrating the applicability of the method for monitoring residues of these pharmaceuticals.

Determination of related substances in egg yolk lecithin by HPLC-CAD and characterization of its profiling by HPLC-Q-TOF-MS.

A high-performance liquid chromatography (HPLC) method has been developed for the determination of related substances in egg yolk lecithin. Chromatographic separation was achieved using a gradient elution on a Waters Xbridge HILIC column maintained at 35 â„ƒ. Mobile phase A was composed of water-acetonitrile (80:20, v/v, containing 5 mM ammonium acetate), and mobile phase B was composed of acetonitrile. Analytes were monitored by a charged aerosol detector (CAD) at 50 â„ƒ. The novel HPLC-CAD method was selective and sensitive for the determination of related substances in egg yolk lecithin in its commercial bulk batches. It was also successfully validated by the International Council for Harmonisation (ICH) guidelines. The method will be a renewal of an old Chinese Pharmacopoeia method (2020 edition). Moreover, quadrupole time-of-flight mass spectrometry (Q-TOF-MS) was integrated with HPLC to investigate phospholipid species in egg yolk lecithin. This work provides comprehensive composition profiles of egg yolk lecithin, thereby accelerating the quality control, development, and application of egg yolk lecithin.

Modeling pKa of the Brønsted Bases as an Approach to the Gibbs Energy of the Proton in Acetonitrile.

A simple but efficient computational approach to calculate pKa in acetonitrile for a set of phosphorus, nitrogen, and carbon bases was established. A linear function that describes relations between the calculated ΔG'a.sol(BH+) and pKa values was determined for each group of bases. The best model was obtained through the variations in the basis set, in the level of theory (density functionals or MP2), and in the continuum solvation model (IPCM, CPCM, or SMD). The combination of the IPCM/B3LYP/6-311+G(d,p) solvation approach with MP2/6-311+G(2df,p)//B3LYP/6-31G(d) gas-phase energies provided very good results for all three groups of bases with R2 values close to or above 0.99. Interestingly, the slopes and the intercepts of the obtained linear functions showed significant deviations from the theoretical values. We made a linear plot utilizing all the conducted calculations and all the structural variations and employed methods to prove the systematic nature of the intercept/slope dependence. The interpolation of the intercept to the ideal slope value enabled us to determine the Gibbs energy of the proton in acetonitrile, which amounted to -258.8 kcal mol-1. The obtained value was in excellent agreement with previously published results.

HPLC-UV method validation for quantification of ß-carotene in the development of sustained release supplement formulation containing solid dispersion-floating gel in situ.

Despite the health benefits of ß-carotene, its activity has been hampered by poor aqueous solubility and low oral bioavailability. Therefore, it is crucial to develop a new approach to overcome these problems. In this study, we developed a dry powder supplement comprising a combination approach of solid dispersion and floating gel in situ of ß-carotene to enhance the solubility and achieve sustained release behavior. Here, we validated an HPLC method to quantify ß-carotene as per the guidelines from ICH. The analytical method was validated in methanol and Fasted-State Simulated Gastric Fluid (FaSSGF) to determine ß-carotene in recovery and in vitro release studies, respectively. A simple HPLC method using Xselect CSH™ C18 column (Waters, 3.0 × 150 mm) with the particle size of 3.5 µm was validated with 100% acetonitrile as the mobile phase. The calibration curves were found to be linear with LLOQ values < 3 ng/mL. Importantly, the method was accurate and precise without a carry over effect and successfully applied to determine the ß-carotene concentration in the content analysis of the compound and in vitro drug release from floating gel in situ laden with solid dispersion formulations. The sensitivity of the method obtained here offers a wide potential use in various applications in drug delivery systems.

[Rapid determination of 22 functional components in cosmetics using ultra-high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

Plant components from extracts of Sophora flavescens, rhodiola, ginseng, Centella asiatica, and tea play important roles in skin whitening, moisturizing, anti-aging, sun protection, anti-inflammation, antiseptic, bacteriostatic, and other effects of cosmetics. At present, no relevant standard methods have been established to detect the addition amounts of plant extracts in cosmetics. In addition, plant extracts listed in product labels may be undetectable due to their addition in trace quantities and the lack of technical support. Therefore, a quantitative method for the simultaneous determination of 22 functional components in cosmetics was established by ultra-high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UHPLC-LTQ/Orbitrap MS). Target compounds were extracted with methanol from samples using ultrasonic extraction, and then separated on a C18 column (100 mm × 2.1 mm, 1.8 µm) with gradient elution of 0.1% (v/v) formic acid aqueous solution (A) and acetonitrile (B). The gradient elution program were as follows: 0-5 min, 5%B-8%B; 5-25 min, 8%B-60%B; 25-35 min, 60%B-80%B; 35-36 min, 80%B-5%B; 36-45 min, 5%B. The flow rate was 0.3 mL/min and the injection volume was 5 µL. Accurate masses of precursor ions were used to detect cosmetic functional components in positive ionization mode. The fragment ions obtained by higher energy collisional dissociation were used for confirmation of the functional components. Each compound showed good linearity. The limits of detection (LODs) were in the range of 0.003-2.01 mg/kg, and the limits of quantification (LOQs) were in the range of 0.02-4.36 mg/kg. Recoveries at three levels were 63.2%-125.1%, and relative standard deviations (RSDs) were 0.18%-10.9%. Fifty-four batches of samples labeled with four monomer functional components and nine plant extracts were tested. In the 17 batches of samples labeled with nicotinamide, 4 batches labeled with caffeine, and 6 batches labeled with Sophora flavescens root extract, the labeled functional components were detected. One out of 11 batches of samples labeled with D-panthenol was not detected. Three of the seven batches of samples labeled with ascorbyl glucoside were not detected. In the 21 batches of samples labeled with licorice extracts, the corresponding functional components were not detected in 9 batches. In the 21 batches of samples labeled with Centella asiatica extract, the corresponding functional components were not detected in 11 batches. In the 13 batches of samples labeled with tea extract, the corresponding functional components were not detected in 8 batches. In 11 of the 12 batches containing ginseng root extract, the corresponding functional components were not detected. In five of the six batches of astragalus membranaceus root extract samples, the corresponding functional components were not detected. In samples labeled with Polygonum cuspidatum root extract, Rehmannia glutinosa root extract, and Ophiopogon japonicus root extract, the corresponding functional components were detected. The method is simple, rapid, reliable, accurate, and suitable for the determination of the 22 functional components in cosmetics.

Quantification of Arbutin in Cosmetics, Drugs and Food Supplements by Hydrophilic-Interaction Chromatography.

Arbutin, the glucoside of hydroquinone, exists in two isomers, α-arbutin and ß-arbutin. The synthetic α isomer is mainly used as a skin brightening agent, while ß-arbutin occurs naturally, for instance in bearberry, and is used in drugs for treatment of lower urinary tract infections and as a food supplement. Since both isomers can be harmful at high concentrations, methods for their quantification are required. Classically they have been determined by reversed-phase chromatography, but separation of both isomers is often unsatisfactory. Here we present a simple and reliable method for quantification of α- and ß-arbutin based on hydrophilic-interaction chromatography. Prior to analysis, interfering compounds that would frequently be present in cosmetics and drugs, particularly biopolymers, were efficiently removed by precipitation with acetonitrile. In this paper, for separation, a Cyclobond I 2000 5 µm 250 × 4.6 mm column was employed as stationary phase and acetonitrile/water 92/8 (v/v) was used as an eluent at a flow rate of 0.8 mL min−1. For quantification, a UV detector operating at 284 nm was applied. Although analysis took less than 10 min, baseline separation of α- and ß-arbutin was achieved. The response was highly linear (r > 0.999) and the method had, for both α- and ß-arbutin, a LOD of 0.003% (w/w) and a LOQ of 0.009% (w/w). Moreover, the method showed excellent intra-day and inter-day repeatability with relative standard deviations in the range of 0.5% to 2.3% and 1.0% to 2.2%, respectively, with cosmetics, drugs and food supplements as samples.