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14 pages, 4253 KiB

Open AccessArticle

Quantitative Study of Spodumene by Time-of-Flight Secondary Ion Mass Spectrometry (tof-SIMS)

by Xijuan Tan

Molecules 2025, 30(7), 1552; https://doi.org/10.3390/molecules30071552 - 31 Mar 2025

Viewed by 195

Abstract

In this paper, the quantitative feasibility of time-of-flight secondary ion mass spectrometry (tof-SIMS) for major and minor elements in spodumene was evaluated in terms of calibration method with a matrix-matched or non-matrix-matched standard and an internal standard element using Al or Si. The [...] Read more.

In this paper, the quantitative feasibility of time-of-flight secondary ion mass spectrometry (tof-SIMS) for major and minor elements in spodumene was evaluated in terms of calibration method with a matrix-matched or non-matrix-matched standard and an internal standard element using Al or Si. The matrix-matched standard calibration method was studied using spodumene 503R as the external standard and unknown sample, with signal intensities collected under positive ion mode using 100 µm of raster size. The sensitivities of Li, Na, Al, Si, Mn, and Fe were obtained by applying the sample-standard bracketing method, and the corresponding concentrations were given as the division of signal intensities by sensitivities. It was found that there were no significant differences between concentration results using Al and Si as the internal standard element. After 100% normalization, the concentrations at a 95% confidence level of matrix Li₂O, Al₂O₃, and SiO₂ in oxide form were found to be 7.62 ± 0.27%, 27.68 ± 0.10%, and 64.32 ± 0.29%, respectively, which agreed with those from LA-ICPMS measurements and/or EPMA analyses. The comparison of the minor components including Na₂O, MnO, and FeO showed that the contents from tof-SIMS were consistent with references from LA-ICPMS, giving ratios within 0.98–1.02. Furthermore, the element behavior investigation of NIST SRM 610 showed that the ionization efficiencies differentiated among the studied elements, resulting in far lower sensitivities of Li, Na, Mn, and Fe in spodumene than the values from the proposed matrix-matched standard calibration method. Thus, the matrix-matched standard calibration method for element determination of spodumene by tof-SIMS was recommended. The successful determination of major and minor elements in spodumene also promises the future application of tof-SIMS to trace element quantification. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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18 pages, 3939 KiB

Open AccessArticle

Influence of Neutralization Precipitation Conditions on the Physical Stability of Amorphous Solid Pharmaceuticals

by Zhihui Yuan, Xu Liao, Bowen Zhang, Asad Nawaz and Zunhua Li

Molecules 2025, 30(4), 764; https://doi.org/10.3390/molecules30040764 - 7 Feb 2025

Viewed by 529

Abstract

This research focused on the precipitation of amorphous forms of nilotinib with high physical stability through the manipulation of various parameters in the neutralization reaction, specifically the quantity of nilotinib, the pH value, and the concentration of HCl. To assess the physical stability [...] Read more.

This research focused on the precipitation of amorphous forms of nilotinib with high physical stability through the manipulation of various parameters in the neutralization reaction, specifically the quantity of nilotinib, the pH value, and the concentration of HCl. To assess the physical stability of the amorphous nilotinib, various characterization techniques, including PXRD, DSC, and FBRM, were utilized in conjunction with analytical methods such as PDF, PCA, and R_c value. The findings demonstrated that the ideal physical stability was attained with a nilotinib quantity of 0.5 g, a pH value of 11.70, and 7.5 mL of HCl with a concentration of 2.0 mol/L. It is important to acknowledge that this observation is specific to the current experimental configuration and may not hold in the context of a scaled-up experiment. Furthermore, the combination of PDF and R_c was identified as an innovative and effective method for assessing physical stability, demonstrating advantages over traditional accelerated stability testing approaches. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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18 pages, 4672 KiB

Open AccessArticle

High-Resolution LC-MS Simultaneous Quantification of Forty-Six Compounds from Jatropha podagrica Fruit Recommends Four Top Antioxidant Contributors as Q-Markers

by Rongxin Cai, Xican Li, Honghong Liang, Shaoman Chen, Yuting Huang, Hanxiao Chai, Rongrong Lin and Guihua Jiang

Molecules 2025, 30(3), 722; https://doi.org/10.3390/molecules30030722 - 5 Feb 2025

Cited by 1 | Viewed by 593

Abstract

There has been no chemical analysis of the fruit of medicinal plant Jatropha podagrica until now. The current study aimed to qualitatively and quantitatively analyze the J. podagrica fruit using a high-resolution LC-MS strategy, i.e., library-comparison ultra-high-performance liquid chromatography-Quadrupole-Orbitrap-tandem mass spectrometry. The strategy [...] Read more.

There has been no chemical analysis of the fruit of medicinal plant Jatropha podagrica until now. The current study aimed to qualitatively and quantitatively analyze the J. podagrica fruit using a high-resolution LC-MS strategy, i.e., library-comparison ultra-high-performance liquid chromatography-Quadrupole-Orbitrap-tandem mass spectrometry. The strategy putatively identified 46 compounds from fresh fruit. During the putative identification, 10 isomers (e.g., (vitexin vs. isovitexin) were completely distinguished from each other. Thereafter, all 46 compounds were simultaneously quantified using authentic standard comparison method. Finally, they were also subjected to the 2,2′-azino bis (3-ethylbenzothiazolin-6-sulfonic acid radical (ABTS^+•)-scavenging assay to characterize their relative antioxidant capacities. Their antioxidant capacities were thus multiplied by chemical contents to calculate their antioxidant contribution values, respectively. Corilagin, gallic acid, ellagic acid, and phillygenin exhibited the highest antioxidant contribution percentages and thereby were suggested as the four top antioxidant contributors. The four are recommended to build up a quality-markers (Q-markers) system of J. podagrica fruits. All these findings can help to develop J. podagrica fruits as a potential resource of natural medicine. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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17 pages, 3111 KiB

Open AccessArticle

Novel Spectrophotometric Method for Robust Detection of Trace Copper and Cobalt in High-Concentration Zinc Solution

by Fengbo Zhou, Bo Wu and Jianhua Zhou

Molecules 2024, 29(23), 5765; https://doi.org/10.3390/molecules29235765 - 6 Dec 2024

Viewed by 725

Abstract

In the purification process of zinc hydrometallurgy, the spectra of copper and cobalt seriously overlap in the whole band and are interfered with by the spectra of zinc and nickel, which seriously affects the detection results of copper and cobalt in zinc solutions. [...] Read more.

In the purification process of zinc hydrometallurgy, the spectra of copper and cobalt seriously overlap in the whole band and are interfered with by the spectra of zinc and nickel, which seriously affects the detection results of copper and cobalt in zinc solutions. Aiming to address the problems of low resolution, serious overlap, and narrow characteristic wavelengths, a novel spectrophotometric method for the robust detection of trace copper and cobalt is proposed. First, the Haar, Db4, Coif3, and Sym3 wavelets are used to carry out the second-order continuous wavelet transform on the spectral signals of copper and cobalt, which improves the resolution of copper and cobalt and eliminates the background interference caused by matrix zinc signals and reagents. Then, the information ratio and separation degree are defined as optimization indexes, a multi-objective optimization model is established with the wavelet decomposition scale as a variable, and the non-inferior solution of multi-objective optimization is solved by the state transition algorithm. Finally, the optimal second-derivative spectra combined with the fine zero-crossing technique are used to establish calibration curves at zero-crossing points for the simultaneous detection of copper and cobalt. The experimental results show that the detection performance of the proposed method is far superior to the partial least squares and Kalman filtering methods. The RMSEPs of copper and cobalt are 0.098 and 0.063, the correlation coefficients are 0.9953 and 0.9971, and the average relative errors of copper and cobalt are 3.77% and 2.85%, making this method suitable for the simultaneous detection of trace copper and cobalt in high-concentration zinc solutions. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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12 pages, 2082 KiB

Open AccessArticle

M2BPgs-HCC: An Automated Multilectin Bead Array Indicating Aberrant Glycosylation Signatures Toward Hepatitis C Virus-Associated Hepatocellular Carcinoma Prognosis

by Hiroko Shimazaki, Haruki Uojima, Kazumi Yamasaki, Tomomi Obayashi, Sayaka Fuseya, Takashi Sato, Masashi Mizokami and Atsushi Kuno

Molecules 2024, 29(23), 5640; https://doi.org/10.3390/molecules29235640 - 28 Nov 2024

Viewed by 1055

Abstract

Regular monitoring of patients with a history of hepatitis C virus (HCV) infection is critical for the detection and management of hepatocellular carcinoma (HCC). Mac-2 binding protein glycosylation isomer (M2BPGi) has been used to monitor fibrosis progression and predict HCC. However, HCC prediction [...] Read more.

Regular monitoring of patients with a history of hepatitis C virus (HCV) infection is critical for the detection and management of hepatocellular carcinoma (HCC). Mac-2 binding protein glycosylation isomer (M2BPGi) has been used to monitor fibrosis progression and predict HCC. However, HCC prediction based on M2BPGi has not been optimized. Here, we identified HCC risk-related glycan signatures of M2BP using a newly developed automated bead array with multiplexed lectins. Among 955 patients with HCV who achieved sustained virological response following direct-acting antiviral treatment, we compared M2BP glycosylation from sera of 42 patients diagnosed with HCC during follow-up and 43 without HCC (control) by the lectin microarray. At the HCC observation point, we found significant differences in 17 lectins. Using an automated bead array with 12 of 17 lectins, a principal component analysis (PCA) biplot differentiated HCC from control, along the PC1 axis, explaining 75.2% of variance. Based on PC1, we generated a scoring formula for an HCC-related glycosylation signature on M2BP (M2BPgs-HCC), showing good diagnostic performance for HCC (p = 2.92 × 10⁻⁸, AUC = 0.829). This automated multilectin bead array improved the ability of M2BP to detect HCC, providing a candidate test for HCC surveillance in combination with other HCC markers. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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17 pages, 4869 KiB

Open AccessArticle

UHPLC-QTOF-MS-Based Targeted Metabolomics Provides Novel Insights into the Accumulative Mechanism of Soil Types on the Bioactive Components of Salvia miltiorrhiza

by Mengmeng Hou, Dan Gao, Weixu Chen, Wenjun Jiang, Dade Yu and Xiwen Li

Molecules 2024, 29(17), 4016; https://doi.org/10.3390/molecules29174016 - 25 Aug 2024

Cited by 2 | Viewed by 1214

Abstract

The root of Salvia miltiorrhiza Bunge (SMB) has been widely used to treat cardiovascular diseases. However, the contents of secondary metabolites in the roots from different production areas are significantly different, and the impact of soil factors on this accumulation remains unclear. Therefore, [...] Read more.

The root of Salvia miltiorrhiza Bunge (SMB) has been widely used to treat cardiovascular diseases. However, the contents of secondary metabolites in the roots from different production areas are significantly different, and the impact of soil factors on this accumulation remains unclear. Therefore, this study aimed to elucidate the regularity of variation between the active components and soil factors through targeted metabolomics and chemical dosimetry. Soils were collected from five different cities (A, B, C, D, and E) and transplanted into the study area. The results showed that there were significant differences in the soil fertility characteristics and heavy metal pollution levels in different soils. Ten water- and twelve lipid-soluble metabolites were identified in SMBs grown in all soil types. SMBs from D cities exhibited the highest total tanshinone content (p < 0.05). The salvianolic acid B content in SMBs from E cities was the highest (p < 0.05). Interestingly, correlation analysis revealed a significant negative correlation between the accumulation of lipid-soluble and water-soluble metabolites. Double-matrix correlation analysis demonstrated that available potassium (AK) was significantly negatively correlated with salvianolic acid B (r = −0.80, p = 0.0004) and positively correlated with tanshinone IIA (r = 0.66, p = 0.008). Conversely, cadmium (Cd) and cuprum (Cu) were significantly positively and negatively correlated with salvianolic acid B (r = 0.96, p < 0.0001 and r = 0.72, p = 0.0024) and tanshinone IIA (r = 0.40, p = 0.14 and r = 0.73, p = 0.0018), respectively. Mantel’s test indicated that AK (r > 0.52, p < 0.001), Cu (r > 0.60, p < 0.005), and Cd (r > 0.31, p < 0.05) were the primary drivers of the differences in the active components of SMBs. These findings provide a theoretical framework for modulating targeted metabolites of SMB through soil factors, with significant implications for the cultivation and quality control of medicinal plants. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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13 pages, 2941 KiB

Open AccessArticle

Thermoacid Behavior of Serpentinite of the Zhitikarinsky Deposit (Kazakhstan)

by Abdrazak Auyeshov, Kazhymuhan Arynov, Chaizada Yeskibayeva, Kurmanbek Alzhanov and Yerkebulan Raiymbekov

Molecules 2024, 29(16), 3965; https://doi.org/10.3390/molecules29163965 - 22 Aug 2024

Viewed by 746

Abstract

Thermoacid behavior of serpentinite from the Zhitikarinsky field (g. Zhitikara, Kazakhstan). The character of dissolution of heat-treated serpentinite in a narrow temperature range of 600–750 °C is investigated, where the crystal lattice of the structural structure of chrysotile in sulfuric acid is destroyed. [...] Read more.

Thermoacid behavior of serpentinite from the Zhitikarinsky field (g. Zhitikara, Kazakhstan). The character of dissolution of heat-treated serpentinite in a narrow temperature range of 600–750 °C is investigated, where the crystal lattice of the structural structure of chrysotile in sulfuric acid is destroyed. The X-ray and chemical analysis of the products of dissolution of heat-treated serpentinite at 600 °C, 725 °C and 750 °C in sulfuric acid solution show that the reason for the increase in the reactivity of heat-treated serpentinite at 725 °C and 750 °C with respect to the acidic medium and the degree of magnesium extraction into sulfate solution is the formation of periclase (MgO) in the serpentinite composition after heat treatment of them within a temperature range of 600–750 °C. The results were discussed using data obtained by conducting a thermodynamic evaluation of probable reactions during the thermoacid treatment of serpentinite, phase compressions of heat-treated serpentinite at 600–750 °C, and after its acid treatment at 1.0 M H₂SO₄. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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13 pages, 1012 KiB

Open AccessArticle

Comparative Analysis of the Biochemical Composition, Amino Acid, and Fatty Acid Contents of Diploid, Triploid, and Tetraploid Crassostrea gigas

by Jingjing Fu, Enshuo Zhang, Wensong Yu, Weijun Wang, Youmei Sun, Luyao Dong, Yousen Zhang, Guohua Sun, Zan Li, Qihao Luo and Jianmin Yang

Molecules 2024, 29(11), 2671; https://doi.org/10.3390/molecules29112671 - 5 Jun 2024

Cited by 5 | Viewed by 1238

Abstract

Tetraploid oysters are artificially produced oysters that do not exist in nature. The successful breeding of 100% triploid oysters resolved the difficulties of traditional drug-induced triploids, such as the presence of drug residues and a low triploid induction rate. However, little is known [...] Read more.

Tetraploid oysters are artificially produced oysters that do not exist in nature. The successful breeding of 100% triploid oysters resolved the difficulties of traditional drug-induced triploids, such as the presence of drug residues and a low triploid induction rate. However, little is known concerning the biochemical composition and nutrient contents of such tetraploids. Therefore, we investigated compositional differences among diploid, triploid, and tetraploid Crassostrea gigas as well as between males and females of diploids and tetraploids. The findings indicated that glycogen, EPA, ∑PUFA, and omega-3 contents were significantly higher in triploid oysters than in diploids or tetraploids; tetraploid oysters had a significantly higher protein content, C14:0, essential amino acid, and flavor-presenting amino acid contents than diploids or triploids. For both diploid and tetraploids, females had significantly higher levels of glutamate, methionine, and phenylalanine than males but lower levels of glycine and alanine. In addition, female oysters had significantly more EPA, DHA, omega-3, and total fatty acids, a result that may be due to the fact that gonadal development in male oysters requires more energy to sustain growth, consumes greater amounts of nutrients, and accumulates more proteins. With these results, important information is provided on the production of C. gigas, as well as on the basis and backing for the genetic breeding of oysters. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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10 pages, 951 KiB

Open AccessArticle

Development of a Two-Dimensional Liquid Chromatographic Method for Analysis of Urea Cycle Amino Acids

by Yuko Sumida and Makoto Tsunoda

Molecules 2024, 29(3), 700; https://doi.org/10.3390/molecules29030700 - 2 Feb 2024

Cited by 1 | Viewed by 1778

Abstract

The urea cycle has been found to be closely associated with certain types of cancers and other diseases such as cardiovascular disease and chronic kidney disease. An analytical method for the precise quantification of urea cycle amino acids (arginine, ornithine, citrulline, and argininosuccinate) [...] Read more.

The urea cycle has been found to be closely associated with certain types of cancers and other diseases such as cardiovascular disease and chronic kidney disease. An analytical method for the precise quantification of urea cycle amino acids (arginine, ornithine, citrulline, and argininosuccinate) by off-line two-dimensional liquid chromatography (2D-LC) combined with fluorescence-based detection was developed. Before analysis, the amino acids were derivatised with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) to obtain NBD-amino acids. The first dimension involved the reversed-phase separation, in which NBD derivatives of urea cycle amino acids were completely separated from each other and mostly separated from the 18 NBD-proteinogenic amino acids. The samples were eluted with stepwise gradient using 0.02% trifluoroacetic acid in water–acetonitrile as the mobile phase. In the second dimension, an amino column was used for the separation of NBD-ornithine, -citrulline, and -argininosuccinate, while a sulfonic acid column was used to separate NBD-arginine. The developed 2D-LC system was used to analyse human plasma samples. The fractions of NBD-urea cycle amino acids obtained in the first dimension were collected manually and introduced into the second dimension. By choosing appropriate mobile phases for the second dimension, each NBD-urea cycle amino acid eluted in the first dimension was well separated from the other proteinogenic amino acids and interference from endogenous substance. This could not be achieved in the first dimension. The urea cycle amino acids in human plasma sample were quantified, and the method was well validated. The calibration curves for each NBD-urea cycle amino acid showed good linearity from 3 (ASA) or 15 (Orn, Cit, and Arg) to 600 nM, with correlation coefficients higher than 0.9969. The intraday and interday precisions were less than 7.9% and 15%, respectively. The 2D-LC system is expected to be useful for understanding the involvement of the urea cycle in disease progression. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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13 pages, 3365 KiB

Open AccessArticle

The Development of an Extraction Method for Simultaneously Analyzing Fatty Acids in Macroalgae Using SPE with Derivatization for LC–MS/MS

by Taewoo Yum, Eun-Yong Kim, Yeongeun Kim, Sukyoung Choi and Ki-Jung Paeng

Molecules 2024, 29(2), 430; https://doi.org/10.3390/molecules29020430 - 16 Jan 2024

Cited by 1 | Viewed by 1723

Abstract

Fatty acid analysis is an essential step in evaluating the potential of macroalgae for biodiesel production. An extraction method was developed to simultaneously analyze up to five types of biodiesel-fuel-related fatty acids (myristic acid, palmitic acid, cis-palmitvaccenic acid, stearic acid, and oleic [...] Read more.

Fatty acid analysis is an essential step in evaluating the potential of macroalgae for biodiesel production. An extraction method was developed to simultaneously analyze up to five types of biodiesel-fuel-related fatty acids (myristic acid, palmitic acid, cis-palmitvaccenic acid, stearic acid, and oleic acid) in macroalgae using liquid chromatography and tandem mass spectrometry (LC–MS/MS). Lypophilization and solid-phase extraction (SPE) techniques were applied to improve the extraction efficiency and effectively purify samples. The optimal conditions for SPE were set by comparing the recoveries according to the various solvent conditions for each step (loading, washing, and elution). In addition, the introduction of trimethylaminoethyl (TMAE) derivatives to the hydroxyl group of the target analyte increased the ionization efficiency and sensitivity. The derivatized samples were analyzed using the LC–MS/MS method with electrospray ionization in the positive and multiple-reaction monitoring modes. The target analytes were separated and detected within 13.5 min using a CAPCELL PAK C18 MGII S3 column. Gradient elution was performed using distilled water and acetonitrile containing 5 mM ammonium acetate. This method offers a reliable and sensitive tool for the analysis of macroalgae samples for their potential use in biodiesel production. To the best of our knowledge, this is the first report on the simultaneous determination of fatty acids in macroalgae using LC–MS/MS with TMAE derivatization. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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Review

Jump to: Research

11 pages, 457 KiB

Open AccessReview

A Review of Recent Advances in Chromatographic Quantification Methods for Cyanogenic Glycosides

by Yao Zhao, Shuai Wen, Yan Wang, Wenshuo Zhang, Xiangming Xu and Yi Mou

Molecules 2024, 29(20), 4801; https://doi.org/10.3390/molecules29204801 - 11 Oct 2024

Viewed by 1700

Abstract

Cyanogenic glycosides are naturally occurring compounds found in numerous plant species, which can release toxic hydrogen cyanide upon hydrolysis. The quantification of cyanogenic glycosides is essential for assessing their potential toxicity and health risks associated with their consumption. Liquid chromatographic techniques coupled with [...] Read more.

Cyanogenic glycosides are naturally occurring compounds found in numerous plant species, which can release toxic hydrogen cyanide upon hydrolysis. The quantification of cyanogenic glycosides is essential for assessing their potential toxicity and health risks associated with their consumption. Liquid chromatographic techniques coupled with various detectors have been widely used for the quantification of cyanogenic glycosides. In this review, we discuss recent advances in chromatographic quantification methods for cyanogenic glycosides, including the development of new stationary phases, innovative sample preparation methods, and the use of mass spectrometry. We also highlight the combination of chromatographic separation with mass spectrometric detection for the identification and quantification of specific cyanogenic glycosides and their metabolites in complex sample matrices. Lastly, we discuss the current challenges and future perspectives in the development of reliable reference standards, optimization of sample preparation methods, and establishment of robust quality control procedures. This review aims to provide an overview of recent advances in chromatographic quantification methods for cyanogenic glycosides and their applications in various matrices, including food products, biological fluids, and environmental samples. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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