scholarly journals Detection and Quantitative Determination of Alkylnaphthalenes in Latakia Tobacco/ Nachweis und quantitative Bestimmung von Alkylnaphthalinen in Latakia-Tabak

1982 ◽  
Vol 11 (3) ◽  
Author(s):  
G. Nicolaus ◽  
H. Elmenhorst
Keyword(s):  
Quantitative Determination ◽  
Retention Indices ◽  
Kováts Retention Indices ◽  
Ms Analysis ◽  
Quantitative Bestimmung ◽  
First Time

AbstractNaphthalene and alkylnaphthalene were detected qualitatively and quantitatively for the first time in Latakia tobacco. 62 different alkylnaphthalenes were determined by means of GC-MS analysis, 22 of which were exactly allocated structurally by comparing the Kovats retention indices. Besides naphthalene, the following substances were also identified: 1-methylnaphthalene, 2-methylnaphthalene, 1-ethylnaphthalene, 2-ethylnaphthalene, 1-propylnaphthalene, 2-propylnaphthalene, all ten theoretically possible isomers of dimethylnaphthalene, four trimethylnaphthalenes, isobutylnaphthalene and five ethylmethylnaphthalenes. The concentration of the naphthalenes detected in Latakia tobacco is in the region of 1 ppm to 10 ppm, with the focus on 1 ppm to 3 ppm. Alkylnaphthalenes make an important contribution to the aroma of the Latakia tobacco. They clearly modify the burnt aroma of the Latakia phenols to mild, dusty, with earthy undertone.

scholarly journals Quantitative Determination of the Surface Distribution of Supported Metal Nanoparticles: A Laser Ablation–ICP–MS Based Approach

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 77
Author(s):  
Davide Spanu ◽  
Gilberto Binda ◽  
Marcello Marelli ◽  
Laura Rampazzi ◽  
Sandro Recchia ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Laser Ablation ◽  
Quantitative Determination ◽  
Metal Nanoparticles ◽  
Total Mass ◽  
Functional Materials ◽  
Metal Extraction ◽  
Ms Analysis ◽  
Icp Ms

A laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) based method is proposed for the quantitative determination of the spatial distribution of metal nanoparticles (NPs) supported on planar substrates. The surface is sampled using tailored ablation patterns and the data are used to define three-dimensional functions describing the spatial distribution of NPs. The volume integrals of such interpolated surfaces are calibrated to obtain the mass distribution of Ag NPs by correlation with the total mass of metal as determined by metal extraction and ICP–MS analysis. Once this mass calibration is carried out on a sacrificial sample, quantifications can be performed over multiple samples by a simple micro-destructive LA–ICP–MS analysis without requiring the extraction/dissolution of metal NPs. The proposed approach is here tested using a model sample consisting of a low-density polyethylene (LDPE) disk decorated with silver NPs, achieving high spatial resolution over cm2-sized samples and very high sensitivity. The developed method is accordingly a useful analytical tool for applications requiring both the total mass and the spatial distribution of metal NPs to be determined without damaging the sample surface (e.g., composite functional materials and NPs, decorated catalysts or electrodic materials).

Quantitative Bestimmung der hydrierten Pterine und des Xanthommatins in den Augen von Ceratitis capitata WIED (Dipt. Trypetidae)

1965 ◽  
Vol 20 (4) ◽  
pp. 318-322 ◽  
Author(s):  
Irmgard Ziegler ◽  
M. Feron
Keyword(s):  
Quantitative Determination ◽  
Ceratitis Capitata ◽  
Male And Female ◽  
The Third ◽  
Quantitative Bestimmung ◽  
Drastic Increase

In the eyes of male and female flies a quantitative determination of the tetrahydropterin, the corresponding dihydro-compound (Sepiapterin) and of xanthommatin from 0—5 days after hatching was made. The increase of xanthommatin almost stops 24 hours after hatching; about 13 μg are present after that time. The tetrahydropterin, after a drastic increase during the first 24 hours, remains at a level of about 1,1 — 1,2 µg. In contrast the dihydrocompound which is nearly absent at the time of hatching is deposited on the eye-granules between the third and fifth day. At that time, especially in the male the dihydropterin/tetrahydropterin ratio is increased. Starvation during the first 24 hours has essentially no effect on the amount of xanthommation whereas the amount of pterins is markedly reduced.

Eine Methode zur qualitativen und quantitativen Bestimmung von drei Juvenilhormonen von Insekten

1974 ◽  
Vol 29 (3-4) ◽  
pp. 161-168 ◽  
Author(s):  
K. H. Trautmann ◽  
A. Schuler ◽  
M. Suchý ◽  
H.-K. Wipf
Keyword(s):  
Quantitative Determination ◽  
Specific Activity ◽  
High Specific Activity ◽  
Ether Extract ◽  
Qualitative And Quantitative ◽  
Work Up ◽  
First Time ◽  
Very High ◽  
Tenebrio Molitor Larvae

Abstract A method is presented permitting the qualitative and quantitative determination of all three presently known hormones (JH1-3). The determination is based on the method of radioactive isotope dilution, whereby a very small known amount of tritium-labelled JH-1 is added to the ether extract of the particular species. The addition of radioactive JH-1 permits the isolation of all three hormones, because of their similar behaviour during the chosen work up. The quantitative determination was carried out by gas chromatography and the identification was confirmed with the help of retention-times and GC-MS combination. The method was checked by using an extract of Hyalophora cecropia. For the first time methyl 10,11-epoxy-3,7,11-trimethyl-2-trans-6-trans-dodecadienoate (JH-3) could also be identified as the juvenile hormone of Melo­lontha melolontha. In Vanessa io larvae, Tenebrio molitor larvae and adults and in Musca domestica larvae none of the three known hormones could be detected. The preparation of JH-1 labelled with tritium in the methyl group of the ester was accomplished with very high specific activity (4.34 Ci/mmol) of the tritiated acid with diazomethane.

scholarly journals LC-MS/MS analysis of neonicotinoid insecticides: Residue findings in chilean honeys

2018 ◽  
Vol 42 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Raquel Bridi ◽  
Arturo Larena ◽  
Paula Núñez Pizarro ◽  
Ady Giordano ◽  
Gloria Montenegro
Keyword(s):  
Geographical Area ◽  
Pollen Grains ◽  
Neonicotinoid Insecticides ◽  
Galega Officinalis ◽  
Ms Analysis ◽  
Three Samples ◽  
Residue Levels ◽  
New Generation ◽  
First Time

ABSTRACT Neonicotinoids are a relatively new generation of insecticides that have been used for control of pests such as aphids, leafhoppers and whiteflies. This paper presents for the first time a determination of residues of four neonicotinoid insecticides (acetamiprid, thiamethoxam, thiacloprid and imidacloprid) in Chilean honey using QuEChERS extraction and UHPLC-MS/MS analysis. The limits of detection and quantification found for all analytes ranging from 0.34 to 1.43 μg kg-1 and from 0.30 to 4.76 μg kg-1, respectively. The extraction using QuEChERS method provided recoveries over 79% and the precision showed coefficient of variation lower than 20%. These data are in agreement with the international criteria that recommend general recovery limits of 70 - 120%. Of the 16 samples analyzed, in three honey samples neonicotinoids pesticides were detected. These three samples were collected from the same geographical area (Rengo). Fruit and grain production characterize the province of Rengo. The analysis of the botanical origin of these honeys showed the absence of pollen grains of crops and the majority presence of pollen grains of weeds such as Medicago sativa, Galega officinalis and Brassica rapa, which could be associated with crops. Although the residue levels found were low, the results also confirm the actual occurrence of a transfer of neonicotinoid insecticides from exposed honeybees into honey.

Tropane and Pyrrolidine Alkaloids from Convolvulus lanatus Vahl

2008 ◽  
Vol 63 (5-6) ◽  
pp. 321-325 ◽  
Author(s):  
Assem El-Shazly ◽  
Michael Wink
Keyword(s):  
Retention Indices ◽  
Major Constituent ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Qualitative And Quantitative ◽  
Alkaloid Composition ◽  
Kováts Retention Indices ◽  
Aerial Parts ◽  
Pyrrolidine Alkaloids ◽  
First Time

The alkaloid composition of Convolvulus lanatus was investigated by GLC and GLCMS. Altogether, thirteen tropane and pyrrolidine alkaloids were identified on the basis of mass spectral data and/or Kovats retention indices. Twelve of them have been recorded for the first time in this plant and some of these alkaloids were identified for the first time in the genus Convolvulus. Cuscohygrine is the major constituent. Qualitative and quantitative differences of root and aerial parts are discussed.

Online photochemical vapour generation of inorganic tin for inductively coupled plasma mass spectrometric detection

2015 ◽  
Vol 30 (2) ◽  
pp. 410-416 ◽  
Author(s):  
Hualing Duan ◽  
Zhenbin Gong ◽  
Shifeng Yang
Keyword(s):  
Quantitative Determination ◽  
Inductively Coupled Plasma ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection ◽  
Inductively Coupled ◽  
Reproducible Method ◽  
First Time ◽  
Vapour Generation

A highly reproducible method based on the online PCVG technique with ICPMS detection was developed for the quantitative determination of trace levels of inorganic tin for the first time.

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