GEOSTANDARDS AND GEOANALYTICAL RESEARCH
·
2025
·
IF 3.4
Tao He,Hui Cao,Wang Lang,Zhaochu Hu,Zaicong Wang,Zongqi Zou,Wen Zhang,Haihong Chen,Yongsheng Liu
Silver is a powerful geochemical tracer in various geological processes (e.g., hydrothermal deposit formation and evolution of the terrestrial and Martian mantles). The measurement of the ultra-trace Ag (< 0.1 μg g -1 ) in geological samples by ICP-MS is often hindered due to serious polyatomic interferences arising from Zr, Nb and Y elements presented in samples. In this study, a simple and rapid ammonia coprecipitation method was developed to remove interference elements (Zr, Nb and Y) in NH 4 HF 2 digests for the determination of Ag mass fractions in geological materials by isotope dilution ICP-MS (ID-ICP-MS). The removal of interference elements (Zr, Nb and Y) in digestion solutions of geological materials was achieved using ammonia coprecipitation, effectively eliminating their polyatomic interferences. To compensate for the incomplete recovery of Ag during ammonia coprecipitation, isotope dilution calibration was chosen over internal standard calibration to achieve final accurate results. The limit of quantitation for Ag using the proposed method was 1.83 ng g -1 . The results obtained for Ag mass fractionation in nine international geological reference materials were in good agreement with the published values obtained by ID-ICP-MS and ICP-MS/MS. The proposed simple, rapid and practical analytical method for the determination of Ag mass fractions improves our understanding of the behaviour of silver in cosmochemistry and geochemistry studies.
研究领域:
地球化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Chengzhi Liu,Haoxin Ye,Jian Kuang,Gerui Ren,Qing Shen,Hujun Xie,Qunfang Lei,Wenjun Fang
The interfacial composition and thermodynamic parameters of W/O 14-n-14/alcohol/oil/water microemulsions were investigated by dilution method in terms of the number of linking groups n (n = 3–6), water content, alcohol and oil types. The gemini/alcohol/oil/water microemulsion system formed spontaneously with negative Gibbs free energy at 25 ℃. The long carbon chain of alcohol facilitated the formation of W/O microemulsion. With increasing carbon chain length of the oil phase, the absolute value of the Gibbs free energy initially increased and subsequently decreased. With an increasing number of linking groups in gemini surfactants, the amount of alcohol that was required in the interfacial layer increased, thereby hindering alcohol movement from the continuous phase to the interface layer, and the absolute value of the Gibbs free energy also decreased, suggesting that a small value of n is beneficial to the stability of microemulsions.
研究领域:
胶体化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Yongfu Zeng,Qian Li,Ruoyu Zhang,Maolin Wei,Xiaochan Zhao,Liping Hao,Haoran Zhang,Ziqing Wang,Xiujuan Guo,Lianfeng Ai
A stable isotope dilution–liquid chromatography–tandem mass spectrometry method based on a derivatisation strategy involving an N,N'-carbonylimidazole solution (CDI) with 4-(dimethylamino)-benzenemethanamine was developed for the determination of 11 free fatty acids (FFAs) in human blood samples. Serum samples were subjected to liquid‒liquid extraction and centrifuged, and the supernatant was collected for a two-step derivatisation reaction with a CDI and 4-(dimethylamino)-aniline acetonitrile solution. The derivatised solution was separated on a ACQUITY UPLC HSS T3 column (2.1 × 50 mm, 1.8 µm) column with a mobile phase consisting of water–acetonitrile in gradient elution and then detected by tandem mass spectrometry using electrospray ionisation (ESI) and multiple reaction monitoring (MRM) in positive ion mode and quantified using the isotope internal standard method. The effects of the derivatisation reaction time, temperature and concentration of derivatisation reagents on the response values of the analytes were investigated. The optimal conditions were as follows: 1.0 mg mL −1 CDI acetonitrile solution at 25 °C for 25 min, followed by a reaction with a 1.0 mg mL −1 4-(dimethylamino)-benzenemethanamine acetonitrile solution at 70 °C for 30 min. Under the optimal conditions, the limits of detection (LODs) of the 11 FFAs were in the range of 3.0–14.0 ng mL −1 ; the limits of quantification (LOQs) were in the range of 8.0–45.0 ng mL −1 ; and the mean recoveries ranged from 83.4 to 112.8%, with intraday and interday precisions ranging from 0.7 to 9.1% and 3.7–9.5%, respectively. The experimental method is simple in terms of the pretreatment operation, accurate and reliable, and can be applied to the sensitive determination of FFAs in human blood samples.
研究领域:
分析化学
·
医学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Ning Zhang,Yuanyuan Song,Danni Wu,Tian Xu,Meiling Lu,Weibing Zhang,Hailin Wang
Crotonaldehyde (Cro) is one of widespread and genotoxic α,β-unsaturated aldehydes and can react with the exocyclic amino group of 2′-deoxyguanosine (dG) in genomic DNA to form 1, N 2 -propano-2′-deoxyguanosine (ProdG) adducts. In this study, two diastereomers of high purity were prepared, including non-isotope and stable isotope labeled ProdG adducts, and exploited stable isotope dilution-based calibration method. By taking advantage of synthesized ProdG standards, we developed a sensitive ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI–MS/MS) method for accurate quantification of two diastereomers of ProdG adducts. In addition to optimization of the UHPLC separation, ammonium bicarbonate (NH 4 HCO 3 ) was used as additive in the mobile phase for enhancing the ionization efficiency to ProdG adducts and facilitating MS detection. The limits of detection (LODs, S/N = 3) and the limits of quantification (LOQs, S/N = 10) are estimated about 50 amol and 150 amol, respectively. By the use of the developed method, both diastereomers of ProdG adducts can be detected in untreated human MRC5 cells with a frequency of 2.4–3.5 adducts per 10 8 nucleotides. Crotonaldehyde treatment dramatically increases the levels of ProdG adducts in human MRC5 in a concentration-dependent manner.
研究领域:
生物化学
·
毒理学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
Food Analytical Methods
·
2023
·Vol. 16
·期 11
·1673-1679
·
IF 2.9
Li Yanyan,Wang Hongling,Shi Haiming,Guo Qin,Zhang Yuquan,Shi Aimin,Jiang Yuanrong,Wang Qiang
An accurate method was developed to analyze trans - and cis -resveratrols in peanut oils using stable isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The linearity ranges for trans - and cis -resveratrols were determined to be 0.2–100 μg/kg, exhibiting satisfactory correlation coefficients ( r 2 trans > 0.9998, r 2 cis > 0.9996). The limits of detection (LOD) and the limit of quantification (LOQ) were determined to be 0.06 and 0.2 μg/kg, respectively. The recoveries of spiked oil samples ranged from 94.9 to 105.0%, with relative standard deviations (RSDs) less than 6.5% (intra-day) and 7.6% (inter-day). This method was successfully applied to quantify the contents of trans - and cis -resveratrols in commercial peanut oils, ranging from 8.7 to 55.5 μg/kg and 0 to 11.0 μg/kg, respectively. The results demonstrated that the developed method is simple, reliable, and robust for quantifying trans - and cis -resveratrols in peanut oils. Consequently, it exhibits great potential for evaluating adulteration and ensuring the quality control of peanut oils.
研究领域:
食品科学
·
分析化学
·
营养学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2017
·
IF 2.603
Xiangyu Li,Lujuan Liu,Hongjuan Wang,Jian Chen,Beibei Zhu,Huan Chen,Hongwei Hou,Qingyuan Hu
A stable method, using isotope dilution liquid chromatography-tandem mass spectrometry (LC–MS/MS), to simultaneously determine six aldehyde-DNA adducts was developed and applied to the analysis of human salivary DNA samples. The detection limit of these six DNA adducts was in the range of 0.006–0.014 ng/mL and that of the quantification limit was 0.017–0.026 ng/mL. The intra-day and inter-day precision of all aldehyde-DNA adducts was <10%. The analysis was completed within 25 min. Additionally, a noninvasive technique was used to collect the DNA samples from human saliva. The new method was successfully applied for the analysis of salivary DNA of nonsmokers and smokers. Five aldehyde-DNA adducts were detected in both smoker and nonsmoker salivary DNA, while α-Acr-dG was not detected in all the samples. Among these detected DNA adducts, no significant differences were found between smoker and nonsmoker (p > 0.05). This may due to the individual detoxifying differences or environmental and endogenous exposure. Our study provides a rapid and selective method to simultaneously detect six aldehyde-DNA adducts and to assess potential DNA damage induced by aldehydes,
研究领域:
分析化学
·
分子生物学
·
毒理学
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Xiuqing Li,Hongfen Bian,Siming Yu,Wei Xiao,Jianying Shen,Caifeng Lan,Kenan Zhou,Caihong Huang,Lei Wang,Dan Du,Yuehe Lin,Yong Tang
Using an enzyme-linked immunosorbent assay (ELISA) and limited dilution methods to screen and clone antigen-specific hybridoma cells is extremely time-consuming and labor-intensive. This work features a simple and rapid cell surface fluorescence immunosorbent assay (CSFIA), designed for the detection and isolation of antigen-specific hybridoma clones. In this assay, antigens are first anchored to the hybridoma cell surface through a dual-functioning molecular Oleyl-PEG4000-NHS. Specific antibodies secreted from hybridoma cells are then captured by the antigens on the cell surface. Positive hybridoma cells are stained using a fluorescently labeled anti-mouse IgG-Fc antibody. After the addition of a methylcellulose semisolid medium, positive clones are easily picked using a pipet. These positive cell clones can be used to produce monoclonal antibodies after direct expansion. Using this method, positive hybridoma clones against both malachite green and porcine epidemic diarrhea virus are selected with high efficiency. Compared to the ELISA-based method, the CSFIA-based method achieved the capability of isolating >2-fold more hybridoma clones in <25% of the corresponding processing time. In brief, the CSFIA-based method is highly efficient and inexpensive with a simple and direct operation, which is an excellent candidate method for antigen-specific positive clone isolation in a monoclonal antibody preparation.
研究领域:
免疫学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
·
2025
·
IF 3.1
Jin-Hua Liu,Xiao-Dong Deng,Jian-Wei Li,Lan-Ping Feng,Thomas J. Algeo
The rhenium–osmium (Re–Os) isotopic system has emerged as a widely utilized tool in cosmochemistry and high-temperature geochemical studies. A critical prerequisite for high-precision Os isotope analysis via Negative Thermal Ionization Mass Spectrometry (N-TIMS) involves achieving complete isotopic equilibrium between the sample and spike through the isotope dilution technique. In this study, we present an innovative technique to address valence state disparities in Os species within mixed solutions, thereby enabling effective isotopic equilibration through a chemical reducing reaction with a strong reductant under ambient conditions. Experimental results demonstrate that a solution containing 0.05 mol L−1 hydroxylamine hydrochloride (NH2OH·HCl) coupled with 0.01 mol L−1 HBr effectively stabilizes a nanogram-level Os mass. Systematic optimization of reductant concentration and sample-to-reductant ratio yielded a mean 190Os/188Os value of 1.2280 ± 0.0006 (2s, n = 18) for a mixed Os spike solution, closely aligned with the recommended value of 1.2278 ± 0.0003 (2s, n = 12) obtained through the conventional Carius tube method. Controlled comparative experiments revealed critical considerations for method implementation: (1) a freshly prepared reductant must be employed immediately to ensure reagent efficacy, and (2) precise absolute volume control of the reductant solution is essential to mitigate potential losses of volatile OsO4 linked to extended decomposition times. This novel approach successfully achieves isotopic equilibration between sample–spike and inter-spike components under ambient conditions, offering significant analytical advantages over traditional methods. The validity of the proposed approach was demonstrated by analyzing reference material WMS-1a yielding a 187Os/188Os value of 0.1665 ± 0.0006 (2s, n = 5), which agrees within uncertainty with the established value of 0.1664 ± 0.0003 (2s, n = 5) obtained via the Carius tube method. The protocol enhances operational efficiency by reducing equilibration time and explosive risk, and decreases procedural Os blanks via reducing material and reagent consumption. The combined improvements in precision, cost-effectiveness, and methodological flexibility position this technique as a valuable advancement in Os isotope geochemistry.
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2013
·
IF 5.695
Ruichuan Yin,Shengquan Liu,Chao Zhao,Meiling Lu,Moon-shong Tang,Hailin Wang
Acrolein (Acr), a ubiquitous environmental pollutant, can react directly with genomic DNA to form mutagenic adducts without undergoing metabolic activation. To sensitively and accurately quantify Acr–DNA adducts (including structural isomers and stereoisomers) in human leukocytes, we developed an enhanced stable isotope dilution ultrahigh performance liquid chromatography (UHPLC)–tandem mass spectrometry (MS/MS) method using ammonium bicarbonate (NH4HCO3), which is thermally unstable and degrades readily to carbon dioxide and ammonia in heated gas phase. Interestingly, ammonium bicarbonate (as an additive to the mobile phase) not only improves the protonation of AcrdG adducts but also suppresses the formation of MS signal-deteriorating metal–AcrdG complexes during electrospray ionization, leading to the enhancement of their MS detection by 2.3–8.7 times. In contrast, routinely used ammonium salts (ammonium acetate and ammonium formate) and formic acid do not show similar enhancement. The developed method is potentially useful for enhancing ESI-MS detection of other modified 2′-deoxyribonucleosides that have difficulty in protonation and may form excess metal complexes during electrospray ionization. The limits of detection (LODs, S/N = 3) are estimated to be about 40–80 amol. By the use of the developed method, we found that the Acr adducts of three nucleotides (dG, dA, and dC) can be detected in human leukocytes. In addition to the known γ-AcrdG, α-AcrdA is also identified as an Acr-adduct of high abundance (2.5–20 adducts per108 nts).
研究领域:
分析化学
·
环境科学
·
分子生物学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MYCOPATHOLOGIA
·
2025
·Vol. 190
·期 5
·1-13
·
IF 2.9
Han Xiang,Zhang Heng,Mao Yuqi,Ling Wenhao,Ge Lu,Tang Menghua,Sun Yi,Wu Zhiqin
Introduction Fungal keratitis (FK), a severe ocular infection caused primarily by Fusarium spp. and Aspergillus spp., remains a major cause of blindness worldwide. Current treatment relies on antifungal agents, though emerging azole resistance in Aspergillus fumigatus complicates therapeutic outcomes. Materials and methods We isolated a clinical FK strain and assessed its antifungal susceptibility using broth microdilution and E-test methods, followed by sequencing of the cyp51A gene’s promoter region and coding sequence (CDS) to identify resistance-associated mutations. Results The isolate, confirmed as A. fumigatus (Aftr46-001) via ITS and β-tubulin sequencing, exhibited elevated minimum inhibitory concentrations (MICs) 16 µg/mL for itraconazole (ITC), 32 µg/mL for isavuconazole (ISA), 32 µg/mL for voriconazole (VRC), and 1 µg/mL for posaconazole (POS) by broth microdilution. E-test results revealed an ITR MIC of 12 µg/mL, ISA MIC 32 µg/mL, VRC MIC 32 µg/mL, and POS MIC of 2 µg/mL. The isolate exhibited MICs values at or above the CLSI and EUCAST epidemiological cutoff values (ECVs): 1 µg/mL for ITC, ISA, and VRC according to CLSI (with insufficient data to establish a POS ECV), and 1 µg/mL for ITC and VRC, 2 µg/mL for ISA, and 0.25 µg/mL POS per EUCAST criteria. Genotypic analysis identified a 46-nucleotide tandem repeat in the cyp51A promoter and two nonsynonymous mutations (Y46F, F70L). Discussion This represents the first report of a cyp51A TR46/Y46F/F70L-harboring A. fumigatus strain isolated from FK, with potential agricultural environmental origins, suggesting that this mutation may have become a potential driver of azole-resistant FK in areas with high agricultural exposure, urgently needing to be included in local treatment guidelines and active surveillance systems. The isolate’s resistance to all tested azoles underscores the clinical challenge posed by this genotype. Following this combined intervention, the patient's left eye vision improved from counting fingers at 1 m upon admission to a final visual acuity of 0.3, indicating that combined surgery and local high-dose drug delivery can serve as an effective strategy for drug-resistant FK. These findings highlight the importance of monitoring azole-resistant A. fumigatus strains to guide clinical treatment. The global increase in azole drug resistance further highlights the urgency and importance of rapid and accurate pathogen identification and drug resistance testing in the current environment.
研究领域:
医学微生物学
·
真菌学
·
抗微生物耐药性
·
眼科学
·
分子生物学
·
临床病理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROBIAL PATHOGENESIS
·
2019
·
IF 2.581
Yanna Ma,Guang Lan,Charlie Li,Edgar Manuel Cambaza,Donghong Liu,Xingqian Ye,Shiguo Chen,Tian Ding
Staphylococcus aureus ( S. aureus ) is a zoonotic bacterium and is among the most important pathogens causing bacterial foodborne diseases. In recent years, disease caused by antibiotic-resistant S. aureus is a serious clinical problem that poses a great threat to public health. In this study, we examined the drug-resistance phenotypes and genotypes of 9 S. aureus strains. One strain was obtained from the China Center for Type Culture Collection (CCTCC), and the remaining eight strains were isolated from food. Two common methods (the Kirby-Bauer disk diffusion and broth microdilution methods) were used to detect bacterial drug resistance . Then, we analysed the relationship between the bacterial drug resistance phenotypes and genotypes. We found that some S. aureus strains isolated from food were drug-resistant or even multi-drug resistant and that there was not a perfect match between resistance phenotypes and genotypes. The viabilities of the drug-sensitive (DS), drug-resistant (DR), and multi-drug resistant (MDR) S. aureus strains were also compared when they were exposed to conditions of acid (HCl, pH = 1.5), heat (63 °C), and osmotic pressure (30% NaCl). The results showed that the DR and MDR bacterial strains had survival rates similar to or higher than those of the DS strains under environmental stress.
研究领域:
微生物学
·
食品科学
·
公共卫生
·
临床微生物学
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2018
·
IF 3.849
Fu Xiang,Jinhai Bai,Xiaobei Tan,Ting Chen,Wei Yang,Feng He
Essential oil is one of the most important bioactive substances of Artemisia argyi Levl. et Van. var. argyi cv. Qiai, a traditional Chinese herb used in folks for centuries. An essential oil was prepared by steam distillation method. Chemical components of the essential oil were explored by gas chromatography-mass spectrometry. Antimicrobial activities of the essential oil were determined by agar disc diffusion assay and double-broth dilution method. Also, antimicrobial mechanisms were investigated based on cytomembrane permeability, protein and K + leakage and electron microscopy. The results showed that the essential oil yield was (0.7 ± 0.02)% (w/w). A total of 32 components were identified, and thujone was found to be the major compound (14.94%), followed by globulol (11.6%), 1,8-cineole (11.31%), 1-caryophyllene (8.11%), camphor (6.87%), α-terpineol (4.69%), caryophyllene oxide (4.05%), borneol (3.95%), eugenol (3.01%), and germacrene D (2.81%). The oil showed antimicrobial activities against both Gram-positive and Gram-negative bacteria. The minimum inhibition concentrations of the essential oil against Staphylococcus aureus , Bacillus cereus , Bacillus subtilis , Listeria monocytogenes , Escherichia coli , Pseudomonas aeruginosa , and Salmonella Typhimurium were 16.0, 16.0, 32.0, 32.0, 32.0, 64.0, and 32.0 μg/mL, respectively. The minimum bactericidal concentrations of the essential oil against bacteria mentioned above were 32.0, 16.0, 64.0, 64.0, 64.0, 128.0, and 64.0 μg/mL, respectively. Supposedly, the possible antimicrobial mechanism of the essential oil involved simultaneous cytomembrane disruption, leading to the leakage of intracellular substances, such as protein and K + . The results indicated that the cytomembrane might be the target of essential oil.
研究领域:
药理学
·
微生物学
·
化学
·
植物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）