TALANTA
·
2024
·
IF 5.6
Jingyun Huang,Qingning Zuo,Xiaoliang Wang,Xiaoping Bai,Qiming Wei,Junnan Zhang,Xiaoshuang Geng,Zitao Yan,Zhen Li,Bo Yang,Lu Li
The real-time detection of gaseous H 2 O and its typical isotopic molecules, e.g., H 2 18 O, D 2 O, HDO, and HTO, is highly desirable in many fundamental scientific studies and practical monitoring, such as mechanistic studies of H 2 O-involved chemical reactions and radiation risk warning of abnormal HTO emissions. However, ionization methods for mass spectrometry (MS) to directly measure isotopic water molecules are limited, and the discrimination of those with similar molecular weights (MWs) usually requires the use of high-resolution mass spectrometers. In this study, we present a highly efficient ionization method for water vapor based on a photoinduced associative ionization (PAI) reaction, where one excited-state CH 2 Cl 2 ∗ reacts with two H 2 O molecules to transfer a proton from one H 2 O molecule to another (i.e., the analyte). Benefit to the distinctive ionization pathway, different featured ions of H 2 O, D 2 O, and H 2 18 O were observed. Surprisingly, each isotopic water molecule has its own unique PAI mass spectrum pattern according to the same ionization principle, which offers a convenient method for distinguishing isotopic water molecules with similar MWs, such as D 2 O, H 2 18 O, and HTO (20 Da), without the need for high-resolution mass spectrometers. The measured detection sensitivities of a laboratory-built PAI time-of-flight mass spectrometer towards D 2 O and H 2 18 O were 1465.1 ± 37.0 and 1324.4 ± 86.4 counts ppbv −1 , respectively, in a detection time of 10 s. The corresponding 3σ LODs were 0.10 and 0.11 ppbv, respectively. This study provides a novel ionization method for the direct detection and discrimination of isotopic water molecules, which has potential to combine with portable MS for on-site measurements.
研究领域:
分析化学
·
环境科学
·
放射化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL MICROBIOLOGY
·
2021
·Vol. 23
·期 6
·3265-3273
·
IF 5.491
Mingliang Zhang,Yijun Ren,Shilong Du,Yidong Zhou,Wankui Jiang,Zhijian Ke,Mingli Jiang,Jiguo Qiu,Jian He,Qing Hong
Summary Pymetrozine is a synthetic pesticide that can be utilized as the sole carbon source by Pseudomonas sp. strain BYT-1. However, the genes involved in the degradation of pymetrozine remain unknown. We used transposon mutagenesis to create a mutant that unable to hydrolyze pymetrozine. The transposon interrupted the gene pyzH , which was cloned by self-formed adaptor PCR. PyzH hydrolyzed the C=N double bond of pymetrozine to produce 4-amino-6-methyl-4,5-dihydro-2 H -[1,2,4]triazin-3-one (AMDT) and nicotinaldehyde; the latter inhibits PyzH activity. PyzH can completely hydrolyze pymetrozine in the presence of dehydrogenase ORF6, which can convert nicotinaldehyde into nicotinic acid and relieve the inhibition. H 2 18 O-labeling experiments showed that the oxygen atom of nicotinaldehyde came from water instead of oxygen. PyzH homologous genes were also found in other soil isolates able to degrade pymetrozine.
研究领域:
微生物学
·
环境科学
·
生物化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2022
·Vol. 20
·期 39
·7814-7820
·
IF 3.89
Bei Wan,Fan Cheng,Hua-Hua Wang,Atif Ali,Yan-Mei Sun,Hai-Yang Liu,Chi-Kwong Chang
Catalytic oxidation using manganese corrole is a hot topic of contemporary porphyrin chemistry, in which PhIO, TBHP, PhI(OAc)2, KHSO5 and m-CPBA are usually used as oxidants. This article reports the first selective oxidation of styrene to benzaldehyde using a manganese(III) corrole catalyst and sodium nitrite (NaNO2) as oxidant and cocatalyst at room temperature. The yield was 158.1% in air and 96.5% under a nitrogen atmosphere, showing oxygen might be involved in the reaction and that NaNO2 is an oxygen source and cocatalyst in the system. The peripheral electron-withdrawing substituents of the manganese corrole were favorable to the catalytic reaction. Radical inhibition and H218O experiments proved that the catalytic reaction was a free radical and hydrolysis-involved reaction.
研究领域:
无机化学
·
有机化学
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）