ACS Earth and Space Chemistry
·
2021
·
IF 3.475
Yang Wu,Xiongxin Dai,Marcus Christl,Hans-Arno Synal,Shan Xing,Shaochun Hou
Plutonium-244 could be the heaviest primordial nuclide existing on earth since the early formation of the solar system. However, the controversial results on the detection of 244Pu in bastnaesite samples require a reassessment. An extremely sensitive analytical method has been developed for the analysis of total 244Pu in completely digested bastnaesite samples by accelerator mass spectrometry. As no true signal of 244Pu was observed, an upper limit for the 244Pu content in the bastnaesite concentrate sample from the Bayan Obo rare-earth deposit (China) was estimated to be 5.4 × 10–19 g/g at 99% confidence level. This result does not agree with the detection of 244Pu at a concentration of 1.0 × 10–18 g/g in bastnaesite reported by Hoffman et al. [Nature1971,234, 132–134] but confirms the latest measurement for an upper limit of 1.5 × 10–19 g 244Pu/g bastnaesite by Lachner et al. [Phys. Rev. C: Nucl. Phys.2012,85, 015801]. Thus, the direct search for primordial 244Pu on earth still remains an open question.
研究领域:
地球化学
·
核物理学
✓ 已验证
DOI
高影响因子
Separations
·
2023
·Vol. 10
·期 4
·231
·
IF 2.6
Chang-Seob Seo,Hyeun-Kyoo Shin
Gongjindan (GJD) is a traditional Korean medicine consisting of four herbal medicines and two animal-derived medicines, and is taken as a tonic in Republic of Korea. In this study, the goal was to develop and validate a simultaneous analytical method to quantify eight compounds in commercially available GJD samples using high-performance liquid chromatography (HPLC), ultra-performance liquid chromatography with tandem mass spectrometry (UPLC–MS/MS), and gas chromatography with tandem mass spectrometry (GC–MS/MS) systems. In HPLC and UPLC–MS/MS, seven components (gallic acid, 5-(hydroxymethyl)furfural, morroniside, loganin, nodakenin, decursin, and decursinol angelate) were separated and quantified using a distilled water–acetonitrile mobile phase system on a Capcell Pak UG80 C18column and an Acquity UPLC BEH C18 column, respectively. Muscone was quantified using GC–MS/MS. The developed assays were validated by evaluating the linearity, limit of detection, limit of quantitation, recovery, and precision. In the regression equations of all compounds, the coefficient of determination was ≥0.9917, showing good linearity. The recovery was 93.70–108.17%, and the relative standard deviation values in the precision test were all <1.50%. Using the developed analysis methods, GJD samples were determined to contain the eight target compounds in concentrations from non-detected to 10.75 mg/g. The analytical assays developed and validated in this study can be used to obtain data for the quality control of commercially available GJDs and for the further expansion of efficacy and clinical studies.
研究领域:
中药学
·
分析化学
·
药理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2017
·Vol. 40
·期 24
·4857-4864
·
IF 2.557
Zhongping Huang,Yueting Xu,Yilei Huang,Charles Liu,Kezhi Jiang,Lili Wang
A novel method based on direct analysis in real time integrated with mass spectrometry was established and applied into rapid determination of ginkgolic acids in Ginkgo biloba kernels and leaves. Instrument parameter settings were optimized to obtain the sensitive and accurate determination of ginkgolic acids. At the sample introduction speed of 0.2 mm/s, high intensity of [M–H] – ions for ginkgolic acids were observed in the negative ion mode by utilization of high-purity helium gas at 450°C. Two microliters of methanol extract of G. biloba kernels or leaves dropped on the surface of Quick-Strip module was analyzed after solvent evaporated to dryness. A series of standard solutions of ginkgolic acid 13:0 in the range of 2–50 mg/L were analyzed with a correlation coefficient r = 0.9981 and relative standard deviation ( n = 5) from 12.5 to 13.7%. The limit of detection was 0.5 mg/L. The results of direct analysis in real time-mass spectrometry were in agreement with those observed by thermochemolysis gas chromatography. The proposed method demonstrated significant potential in the application of the high-throughput screening and rapid analysis for ginkgolic acids in dietary supplements.
研究领域:
分析化学
·
植物化学
✓ 已验证
DOI
PubMed
高影响因子
CHROMATOGRAPHIA
·
2024
·
IF 1.2
Han Kyoung-Moon,Woo In Suk,Park Chae Gyeong,Kim You Kyung,Yang Yoon Ji,Park Bo Reum,Choi Jang Duck,Son Kyung Hun
Preservatives can be used in natural and organic cosmetics to prevent quality deterioration during distribution and use, but the ingredients permitted are limited in the Republic of Korea. A method of simultaneous analysis was developed to monitor natural and organic cosmetics distributed online for the presence of 15 illegally used preservatives. Considering the complexities of the cosmetic matrices, an optimized sample preparation method is essential. Therefore, we developed the optimal purification method by comparing three preparation methods: QuEChERS, high-speed centrifugation, and solid-phase extraction (SPE). The SPE method, which exhibited the most favorable results in matrix reduction, was employed. To establish the SPE-ultra-high-performance liquid chromatography-diode array detection method, factors such as the mobile phase and column were optimized. The optimal separation of the 15 preservatives was observed under the following conditions: mobile phase A comprising 0.1% phosphoric acid in water with 0.5 mM sodium hexanesulfonate and a C 8 column (1.7 μm, 2.1 × 150 mm) as the stationary phase. The linear correlation coefficients were > 0.9998, and the limits of detection and quantitation ranged from 0.05 to 0.67 and 0.15 to 2.02 μg mL −1 , respectively. Using the established analytical method, illegally used preservatives were detected in products claimed to be natural and organic cosmetics sold on the market, and these findings were subsequently verified using liquid chromatography-tandem mass spectrometry. Six out of 47 samples contained phenoxyethanol and parabens. Therefore, this method will help manage the addition of illegal preservatives to natural and organic cosmetics.
研究领域:
分析化学
·
化妆品科学
✓ 已验证
产品关联
DOI
高影响因子
Forensic Toxicology
·
2017
·Vol. 35
·期 2
·275-283
·
IF 3.744
Minakata Kayoko,Yamagishi Itaru,Nozawa Hideki,Hasegawa Koutaro,Suzuki Masako,Gonmori Kunio,Suzuki Osamu,Watanabe Kanako
Human urine samples are easier to obtain than human blood samples due to noninvasiveness. The urine levels of synthetic cannabinoids (SCs) in unchanged forms, however, are usually much lower than their blood and tissue levels and cannot be detected in most cases. Therefore, in the present work a sensitive analytical method was devised for the determination of urine levels of six SCs in unchanged forms such as N -(1-amino-3-methy-1-oxobutan-2-yl)-1-pentyl-1 H -indazole-3-carboxamide (AB-PINACA), N -(1-amino-3-methy-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1 H -indazole-3-carboxamide (AB-FUBINACA), N -[(1 S )-1-(1-aminocarbonyl)-2-methyl-propyl]-1-(cyclohexylmethyl)-1 H -indazole-3-carboxamide (AB-CHMINACA), N -(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-(cyclohexylmethyl)-1 H -indazole-3-carboxamide (MAB-CHMINACA), methyl-2-[1-(5-fluoropentyl)-1 H -indazole-3-carboxamido]-3-methylbutanoate (5F-AMB) and methyl-2-[1-(5-fluoropentyl)-1 H -indazole-3-carboxamido]-3,3-dimethylbutanoate (5F-ADB). These SCs were extracted from urine via liquid–liquid extraction. The identification and quantitation were performed by a relatively new type of an instrument for liquid chromatography–tandem mass spectrometry. The limits of detection were as low as 3–8 pg/mL, and the quantitation range was 10–1000 pg/mL using 400 μL of urine. The urine levels of AB-PINACA and AB-FUBINACA of victim 1 were 23 and 10 pg/mL, those of AB-CHMINACA and 5F-AMB of victim 2 were 239 and 19 pg/mL, and those of MAB-CHMINACA and 5F-ADB of victim 3 were 229 and 19 pg/mL, respectively. To our knowledge, this is the first report dealing with successful analysis of low levels of parent synthetic cannabinoids in authentic human urine specimens.
研究领域:
毒理学
·
药物代谢
·
法医学
·
分析化学
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2023
·
IF 7.4
Qiu-Yue Cheng,Ting Wang,Jun Hu,Hong-Yuan Chen,Jing-Juan Xu
Visible-light-mediated heterogeneous photocatalysis has recently emerged as an environmentally friendly and energy-sustainable alternative for organic transformations. Despite the advancements in developing wide varieties of photocatalysts during the past decades, the accurate probing and identification of the photogenerated species, especially the short-lived radical intermediates, are still challenging. In this work, we reported a hybrid ion emitter that integrated with a pico-liter heterogeneous photocatalytic reactor, which was fabricated by depositing the photocatalyst (e.g., TiO2) into the front tip of a quartz micropipette. Benefited from the dual-function feature of the hybrid micropipette (i.e., a clog-free tip-confined pico-liter reactor for heterogeneous photocatalysis and an ion emitter for nanoelectrospray ionization), sensitized photoredox reactions at the catalyst–solution interface can be triggered upon visible-light irradiation using a cheap LED laser (453 nm), and the newly produced transient radical intermediates can be rapidly transformed into gaseous ions for mass spectrometric identification. Using this novel low-delay coupling device, photogenerated intermediates, including the cationic radicals produced during the photooxidation of anilines and the anionic radicals produced during the photoreduction of quinones, were successfully captured by mass spectrometry. We believe that our hybrid photochemical microreactor/ion emitter has provided a new and powerful tool for exploring the complicated heterogeneous photochemical processes, especially their ultrafast initial transformations.
研究领域:
化学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
Mengqi Xu,Jun Li,Yanlan Bi,Jie Song,Chenyu Fu
A GC-MS method was investigated for simultaneous determination of TBHQ and its transformation products (TBBQ, MAHQ) in fats and oils. Three substances were determined with good linearity of 0.15–100.00 μg/mL (R 2 > 0.9982); low LODs (0.05, 0.17, and 0.10 μg/mL) and the LOQs (0.15, 0.52, and 0.30 μg/mL). The recoveries of the three substances ranged from 93.28 % to 104.64 %. The method is sensitive and reproducible and meets the requirements of the methodology. The initial addition of TBHQ can be assessed with a recovery of > 90 % based on three substances, and the recovery could be closer to the initial addition of TBHQ if more transformation productions of TBHQ were identified with further in-depth study in the future. Compared to reported HPLC methods, the method realizes accurate quantitative detection of TBHQ and its transformation products, which can address the discrepancies between upstream and downstream enterprises in the food industry regarding the amount of TBHQ addition. This method allows downstream companies to precisely control the addition level in order to meet the requirements (maximum of 200 mg/kg based on oil content) regulated by National Standards as well as provide theoretical support for the scientific understanding and application of TBHQ in food industry.
研究领域:
分析化学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2013
·
IF 4.387
Lin Wang,Yunfeng Chai,Zhangqin Ni,Lu Wang,Ruilin Hu,Yuanjiang Pan,Cuirong Sun
A tandem mass spectrometry method for high-sensitivity qualitative and quantitative discrimination of chiral amino compounds is conducted. The method is based on a chemical derivation process that uses a simple reagent, L -1-(phenylsulfonyl)pyrrolidine-carbonyl chloride, as the probe. The method is applicable in both organic solutions and biological conditions. Twenty-one pairs of enantiomer containing amino acids, amino alcohols, and amines are used to produce diastereomers using the probe via in situ reaction for 20 s at room temperature. The resulting diastereomers are successfully recognized based on the relative peak intensities of their fragments in positive mode, with the chiral recognition ability values ranging from 0.35 to 3.83. The L / D ratio of Pro spiked at different concentrations (enantiomeric excess) in both acetonitrile and dog plasma is determined by establishing calibration curves. This method achieves a lower limit of quantification of 50 pmol in analyzing amino acids using an extract ion chromatograph. The relative standard deviation for both qualitative and quantitative results is <5%. Thus, the present method is demonstrated as a new and practical technique of rapidly and sensitively determining enantiomers of amino compounds.
研究领域:
分析化学
·
生物医学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
·
2019
·
IF 1.658
Jie Jiang,Dongmei Zhang,Hong Zhang,Kai Yu,Jing He,Xiangnan Zhang,Na Li
A new method based on droplet spray ionization mass spectrometry (DSI-MS) was developed for rapid qualitative and quantitative determination of melatonin products. Several different melatonin products were analysed with desvenlafaxine as internal standard. Samples only need to be dissolved and diluted without additional preparation procedures. The calibration curve was y = 0.45692 x − 0.00538 with the square of correlation coefficient (R 2 ) of 0.9947 in the concentration range of 0.22–21.50 μM. The limit of detection (LOD) was 0.04 μM and limit of quantification (LOQ) was 0.17 μM, respectively. The recoveries were 88.4%–108.4% and the calculated RSDs were less than 12%. With this DSI-MS method, a single analysis can be completed within 1 min. This method inherent the advantages of rapid and accurate analysis, which can be used for qualitative and quantitative characterization of commercial melatonin products and quality control.
研究领域:
分析化学
·
医学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Jingfeng Li,Lifang Chen,Zhiyun Meng,Guifang Dou
Chitosan has multiple biological activities, but a sensitive and rapid characterization method is yet to be developed for its further application. This study presented an optional mass spectrometry method for the characterization of chitosan. Nine kinds of chitosan (degree of deacetylation (DD), 63.08%–89.06% & MW, 106.1–485.0 kDa) were adopted for the method development. Most species of chitosan, detected by an ESI-MS technique, were observed below 1000 m/z , which seemed that only chito-oligosaccharide (COS) impurities were detected. Then, a sensitive UPLC-ESI-MS/MS method was established to assess the COS impurities in chitosan, and no COS impurities were detected. However, dissociation of chitosan and COSs in the ESI source were observed, and then the mass spectra patterns were deeply evaluated via an accurate Q-TOF mass spectrometer. Our research demonstrated that the mass spectra of COSs and chitosan resulted from the dissociation of glycosidic linkage and dehydration. Although the distribution of GlcN and GlcNAc units in these chitosan samples might be different, similar dissociation efficiencies were observed. Furthermore, good linearities were obtained between the intensities of product ions, detected by an UPLC-pseuedo-MS2 method, and DDs determined by conventional method. This method could be suitable for the DD determination and quantitative analysis of chitosan.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
Bin Li,Wenjing Gao,Ling Ling,Shaoning Yu,Liangqiang Chen,Fan Yang
Lactose is an important nutrient but its content in milk products poses concerns for people with lactose intolerance . Thus, a simple, rapid, and high-throughput assay for lactose determination is needed to maintain specified lactose levels during production and in final milk products. Here, we report a reactive matrix-assisted laser desorption/ionization mass spectrometry ( Re MALDI MS) method for the determination of lactose in milk products. The selective reactivity and the excellent laser absorption properties of 4-hydrazinoquinazoline (4-HQ) matrix increase the sensitivity of traditional MALDI MS analysis of lactose by 100 folds. After optimization of the method, lactose was detected distinctly in milk without pretreatment . Using xylobiose as an internal standard, the assay accurately quantified lactose in the concentration range of 1.00−700 μg/mL (R 2 = 0.994). Due to the high sensitivity and specificity, the lactose content in different types of milk samples was determined successfully, as well as the residual lactose in low-lactose and lactose-free milk.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2022
·Vol. 47
·期 4
·e202100230
·
IF 2.134
Pengfei Su,Xiu-tian-feng E,Jingna Wang,Yanlong Zhu,Gao Zhang,Hai Chang,Ke Liu,Zihui Meng
The detection and separation of impurities are crucial for the quality control of triethylboron. While the purity of triethylboron is the key factor for ballistic performance, impact accuracy, and storage safety. This work will explore a modified gas chromatography-mass spectrometer method to detect and separate the impurities in synthesized triethylboron. They are identified as CH 3 CH 2 OCH 2 CH 3 , (CH 3 CH 2 ) 3 B, (CH 3 CH 2 O) 3 B, CH 3 CH 2 CH 2 CH 2 B(CH 3 CH 2 ) 2 and (CH 3 CH 2 ) 3 O 3 B 3 . Further, optimized GC conditions are demonstrated to quantify the synthesized triethylboron accurately and determine its purity. The purity of triethylboron is 96.39 % via a normalization method with high accuracy (RSD=0.05 %). The optimized GC conditions were as follows: a hydrogen flame ionization detector, nitrogen as carrier gas whose pathway was installed with a water trap and an oxygen trap, an HP-5 capillary column (30 m×0.32 mm×0.25 μm) with the column temperature of 60 °C, an inlet temperature of 120 °C, the detector temperature of 150 °C, and an injection volume of 0.6 μL. This work demonstrates a simple and precise method to analyze the synthesized triethylboron and its impurities.
研究领域:
分析化学
·
材料科学
✓ 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）