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1.
建立了气相色谱-红外光谱(GC-FTIR)联用技术快速鉴别毒品种类和分析毒品纯度的方法,具有操作简单、分析快和准确性高等优点,适合于鉴别未知毒品。利用红外光谱特征吸收峰和色谱相对保留时间鉴别毒品种类,毒品浓度(y)与其色谱峰相对面积(x)在0.05~1.00 mg/L范围内呈现良好的线性关系,据此确定毒品纯度。本方法用于实际案例分析取得了满意的结果。 相似文献
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Masanobu Yamamoto Masaaki Kiso Hiroyuki Yamazawa Jun Takeuchi Tetsu Ando 《Journal of chemical ecology》2000,26(11):2579-2590
Biston robustum Butler, a polyphagous defoliator, multiplied on Hachijo-jima Island in 1997–1998. Based on GC-MS data of authentic standards, an analysis of a pheromone gland extract of the females indicated that it included (Z,Z)-6,9–nonadecadiene (I), (Z,Z,Z)-3,6,9–nonadecatriene (II), cis-(Z)-6,7–epoxy-9–nonadecene (III), and cis-(Z,Z)-6,7–epoxy-3,9–nonadecadiene (IV) in a ratio of 13 : 2 : 70 : 15. The structure of III was confirmed by a GC-MS analysis of another extract treated with dimethyl disulfide (DMDS). This epoxymonoene was successfully converted into the corresponding DMDS adduct that showed diagnostic ions fragmented at an epoxy ring and at thiomethoxy groups reflecting the position of an original double bond. Furthermore, the 6S,7R configuration was assigned for the epoxy ring of III by chiral HPLC analysis. Field examination of synthetic lures revealed that the two epoxy compounds (III and IV) with the 6S,7R configuration were essential components and that the two unsaturated hydrocarbons (I and II) showed a synergistic effect on male attraction. 相似文献
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James Grainger Zheng Li Charisse Walcott Christopher J. Smith Donald G. Patterson Jr. Bretta King 《Polycyclic Aromatic Compounds》2013,33(3-4):489-500
The foundation for a systematic approach utilizing spectral/structural correlations was established for unambiguous identification of monohydroxylated polyaromatic hydrocarbon metabolite (PAHm) isomers. Using elements of a theoretical/empirical valence-bond model developed earlier in our laboratory for isomer identification of chlorinated dibenzo- p -dioxin isomers, both gas chromatography/Fourier transform infrared spectroscopy (GC/FTIR) and carbon-13 nuclear magnetic resonance ( 13 C NMR) spectroscopy were employed for PAHm isomer identification. Results indicate that PAHm isomers also can be systematically identified by these techniques. However, many of the parameters leading to the success of the dioxin analysis (high symmetry of the parent dioxin molecule and laterally stabilized delocalization from chlorine substituents through ether linkage oxonium ions) are not generally present in the PAHm ring systems under investigation. The observed infrared parameters in PAH metabolites are C--O stretch, O--H stretching and bending vibrations, along with C=C skeletal stretching vibrations. In addition, 13 C NMR parameters such as chemical shift perturbations for carbons adjacent to functional groups have been observed. 相似文献
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《化学世界》2017,(10)
采用AntarisⅡ傅里叶近红外光谱技术结合模式识别方法研究鉴别天然彩色棉真伪的可行性。原始光谱经多元校正方法(MSC)消除样本的散射和基线漂移等对光谱的影响后,进行系统聚类分析,聚类分析结果显示天然绿色棉和染色绿色棉能得到清晰地分类。通过不同光谱预处理方法,采用簇类的独立软模式法(SIMCA)建立分类模型,结果显示通过对样品光谱中心化+5点卷积平滑+去趋势预处理,采用SIMCA方法建立的分类模型正确率最高,分类正确率为96.77%,类I的模型方差为0.001 3,类Ⅱ的模型方差为0.000 8。研究表明,AntarisⅡ傅里叶近红外光谱技术可用于天然彩色棉真伪的鉴别。 相似文献
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Yorianta Sasaerila Gerhard Gries Grigori Khaskin Regine Gries Hardi 《Journal of chemical ecology》1997,23(9):2187-2196
Gas chromatographic–electroantennographic detection (GC-EAD) analyses of female nettle caterpillar, Setothosea asigna, pheromone gland extracts revealed seven antennally active compounds. Based on their retention indices on three fused silica columns (DB-5, DB-23, and DB-210), these compounds were hypothesized and, through comparative GC, GC-EAD and GC-mass spectrometry with authentic standards, confirmed to be Δ10-undecenal, dodecanal, (E)-9-dodecenal (E9–12:Ald), (Z)-9-dodecenal, (E)-9-dodecen-1-ol, (E)-9,11-dodecadienal (E9,11–12:Ald), and (E)-9,11-dodecadienol. E9–12:Ald and E9,11–12:Ald were most abundant in female S. asigna pheromone extracts. In field trapping experiments in Palembang, Indonesia, synthetic E9–12: Ald and E9,11–12:Ald at a 1:1 ratio, but not singly, attracted S. asigna males. Attractiveness of these two aldehydes could not be enhanced further through the addition of their corresponding alcohols and/or other aldehydic candidate pheromone components. Use of E9–12:Ald and E9,11–12:Ald for pheromone-based monitoring of S. asigna populations will require lure formulations that minimize pheromone degradation by ultraviolet radiation and atmospheric oxidation. 相似文献
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Islam A Yamamoto M Sugie M Naka H Tabata J Arita Y Ando T 《Journal of chemical ecology》2007,33(9):1763-1773
In addition to 2,13- and 3,13-octadecadien-1-ols and their acetates, aldehyde analogs have been identified from lepidopteran
species in the family Sesiidae. To establish a reliable analytical method for determining the positions and configurations
of the two double bonds in natural pheromone components, all geometric isomers of the 2,13- and 3,13-octadecadienals were
synthesized by Dess-Martin oxidation of the corresponding alcohols with limited isomerization of the double bond at the 2-
or 3-position. GC-MS analysis of these aldehydes showed isomerization of (Z)-2-, (Z)-3-, and (E)-3-double bonds to an (E)-2-double bond, even with a cool on-column injection. In contrast, HPLC analysis with an ODS column was accomplished without
isomerization. The geometric isomers of each dienal eluted in the order ZZ → EZ → ZE → EE. The conjugated 2,13-dienals were detectable in nanogram amounts with a UV detector at 235 nm. Whereas the detection of 3,13-dienals
was difficult because of the lack of a chromophore, a highly sensitive analysis was achieved after derivatization with 2,4-dinitrophenylhydrazine.
LC-MS with atmospheric pressure chemical ionization showed a strong [M-1]- at m/z 443 for the derivatives. Based on these analytical data, a pheromone extract of a sesiid moth, Macroscelesia japona, was examined by HPLC and LC-MS, and it was confirmed that the octadecadienal tentatively identified by a previous GC-MS
analysis did indeed have the 2E,13Z configuration. Furthermore, field evaluation of four synthetic geometric isomers of the 2,13-dienal revealed specific attraction
to a lure with the (2E,13Z)-isomer as a main component. 相似文献
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食用油品质的红外吸收光谱分析 总被引:1,自引:0,他引:1
测定了8种食用油的红外吸收光谱并进行比较分析.结果表明,不同食用油在4000~500cm-1范围内的红外吸收光谱基本相同,在3009,2925,2854,1746,1464,1377,1163,722cm-1处均出现相似的吸收峰,说明不同种类的食用油的主要成分是相同的.各种食用油红外吸收光谱特征峰的相对强度又有所不同,... 相似文献
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Identification of the Female-Produced Sex Pheromone of Tischeria ekebladella, an Oak Leafmining Moth
Béla Péter Molnár Armin Tr?ger Theodora B. Toshova Mitko Subchev Erik J. van Nieukerken J. C. Koster Gábor Sz?cs Miklós Tóth Wittko Francke 《Journal of chemical ecology》2012,38(10):1298-1305
The native leafmining moth Tischeria ekebladella (Lepidoptera: Tischeriidae) feeds on oaks and recently has become a pest of silviculture and urban green areas in central Europe. The behavioral responses of male moths to hexane extracts of whole bodies of calling females or males were tested under laboratory conditions. Only extracts of females elicited responses from males. Analysis of extracts by coupled gas chromatography/electroantennographic detection revealed the presence of two electroantennogram-active peaks. Structure elucidation of these compounds, by gas-chromatography/mass spectrometry and independent synthesis revealed them to be (3Z,6Z,9Z)-tricosa-3,6,9-triene and (3Z,6Z,9Z,19Z)-tricosa-3,6,9,19-tetraene. While the triene was present in both sexes, the tetraene was female-specific. The latter is a new structure for a pheromone component of Lepidoptera and a novel natural product. Field trapping tests, carried out in a mixed oak forest near Budapest (Hungary), using synthetic compounds applied to rubber dispensers, showed that the tetraene per se elicited catches of males in large numbers. When the triene was added to the tetraene in a ratio of 1:1, there was no increase in trap catch; the triene alone did not elicit catches of males. For monitoring this insect, the tetraene, applied to rubber dispensers at a dose of 300?μg, is a potent sex attractant. 相似文献
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Analysis of the adulteration of cod-liver oil with much cheaper oil-like animal fats has become attractive in recent years.
This study highlights an application of Fourier transform infrared (FTIR) spectroscopy as a nondestructive and fast technique
for the determination of adulterants in cod-liver oil. Attenuated total reflectance measurements were made on pure cod-liver
oil and cod-liver oil adulterated with different concentrations of lard (0.5–50% v/v in cod-liver oil). A chemometrics partial
least squares (PLS) calibration model was developed for quantitative measurement of the adulterant. Discriminant analysis
method was used to classify cod-liver oil samples from common animal fats (beef, chicken, mutton, and lard) based on their
infrared spectra. Discriminant analysis carried out using seven principal components was able to classify the samples as pure
or adulterated cod-liver oil based on their FTIR spectra at the selected fingerprint regions (1,500–1,030 cm−1). 相似文献
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Fourier transform infrared absorption measurements of particulate elemental carbon are compared with results obtained using a thermal combustion method of analysis. Ambient air samples were collected on Teflon and quartz filters on each day during the sampling study. The quartz filters were analyzed for elemental and organic carbon using a thermal combustion method of analysis. The Teflon filters were analyzed for elemental carbon by infrared transmission in the region 650–666 cm?1. Good correlation was found between the infrared absorbance on the Teflon filters and the elemental carbon determined from analysis of the quartz filters. Calibration methods for the infrared technique are discussed 相似文献
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Takuya Uehara Hideshi Naka Shigeru Matsuyama Le van Vang Tetsu Ando Hiroshi Honda 《Journal of chemical ecology》2013,39(11-12):1441-1447
Homologs of bombykal, (10E,12Z)-10,12-hexadecadienal, have been reported to be sex pheromones or sexual attractants of several species of sphingid moths. In this study, we identified novel bombykal analogs as sex pheromone components from a Japanese sphingid moth, Dolbina tancrei. Staudinger (Sphingidae: Lepidoptera). Sex pheromone gland extracts from calling female moths were subjected to gas chromatography/electroantennograhic detection (GC/EAD), gas chromatography/mass spectrometry (GC/MS), and gas chromatography (GC) analyses. GC/EAD analyses showed two active components in the crude pheromone extracts. GC/MS analysis determined these two components to be pentadecadienals. GC/MS of their MTAD derivatives showed conjugated double bonds at the 9- and 11-positions, indicating 9,11-pentadecadienals. The isomeric configurations of these candidates were determined by comparison of their Kováts retention indices with those of synthetic compounds. Field bioassays with the four isomers of 9,11-pentadecadienal and their mixtures confirmed that the two sex pheromone components of D. tancrei are (9E,11Z)-9,11-pentadecadienal and (9Z,11Z)-9,11-pentadecadienal, with the highest male catches observed for a 90:10 blend. This is the first report of 9,11-pentadecadienals as sex pheromone components in lepidopteran species. 相似文献
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李洪 《合成材料老化与应用》2020,49(1):53-54
研究使用傅立叶红外光谱(ATR)法对尼龙6和尼龙66两种材质快速鉴别的方法。本文利用傅立叶红外光谱(ATR)法对两件尼龙样品进行鉴别。结果表明,傅立叶红外光谱(ATR)法具有分析时间短、样品需求量小、几乎不破坏样品、不消耗检材、快速简便、分析结果满意等优点。 相似文献
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Simone C. Godoy Marco Flôres Ferrão Annelise E. Gerbase 《Journal of the American Oil Chemists' Society》2007,84(6):503-508
A rapid method for the quantitative determination of the hydroxyl value (OHV) of hydroxylated soybean oils by HATR/FTIR spectroscopy
is described. Calibration standards were prepared by the formic acid/hydrogen peroxide method and OH values were determined
by the official method of AOCS Tx 1a-66, covering an analytical range of 3.5–125 mg of KOH/g of sample. A partial least squares
(PLS) calibration model for the prediction of the hydroxyl value (OHV) was developed based on eight different spectral subregions
between 3,150 and 990 cm−1 and combinations of them. On average, 36 samples were used for the modeling and 17 were used for external validation. The
resulting calibration was linear over the analytical range and had a standard deviation of 2.334. Validation of the method
was carried out by comparing the OHV of a series of hydroxylated soybean oils predicted by the PLS model to the values obtained
by the AOCS standard method. A correlation coefficient of R
2 = 0.9843 and RMSEC and RMSEP values of, respectively, 3.393 and 3.643 were obtained. After the calibration of the spectrometer,
the OHV could be obtained in 2–3 min per sample, a major improvement over conventional wet chemical methods. The advantages
of these methodologies are that they do not destroy the sample, have a lower cost, expedite the analysis and do not produce
residues. Therefore, they may yield excellent results when used to quantify OHV of soybean polyols obtained by hydroxylation
reaction. 相似文献
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以丹参为研究对象,采用傅里叶红外光谱技术结合二阶导数红外光谱对不同产地、不同部位的丹参药材进行区分。结果表明,丹参的红外光谱图中主要吸收峰在3 271、2 929、1 607、1 510、1 397、1 260、1 143、1 026、872cm~(-1)附近,不同产地丹参的吸收峰基本相似,但吸收峰的位置及强度存在一定差异;同一产地丹参的不同部位红外光谱及其特征吸收峰有差异,在1 800~800cm~(-1)范围,须根的吸收峰强度根头部主根,推测须根中丹参酮类、丹酚酸类及糖类含量较根头部和主根中高。同时研究了丹参与其伪品南丹参,在1 607与1 026cm~(-1)附近,丹参吸收峰强度均明显高于南丹参,说明丹参中丹酚酸类和糖类的含量较南丹参高。对不同产地丹参进行系统聚类分析,结果发现,有效成分的分布与丹参的生态和产地呈一定的相关性,样品聚为两大类。红外光谱结合聚类分析法在丹参的鉴别中,不仅可以提供丹参主要化学成分的相关信息,还可以对不同产地的丹参进行分类鉴别。 相似文献