Book Review: Die quantitative Bestimmung der Alkaloide in Drogen und Drogenzubereitungen (Quantitative Determination of Alkaloids in Drugs and Drugs Preparations) by Otto-Erich Schulz and F. Zymalkowski. Vol. 47 in the series “Chemical Analysis”, edited b

1963 ◽  
Vol 2 (10) ◽  
pp. 632-632
Author(s):  
H. Böhme
Keyword(s):  
Chemical Analysis ◽  
Quantitative Determination ◽  
Quantitative Bestimmung

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.

Table II : Quantitative determination of carbonyl compounds at different odour sources (concentrations in ppb) Rendering plant Gelatine plant neighbourhood neighbourhood Formaldehyde 40 16 Acetaldehyde 39 24 Acetone 36 73 Prcpanal 10 -Isobutyraldehyde 10 30 Pentanal 15 19 Hexanal 3.52 Heptanal 12.5 Octanal 10.5 Nonanal 1 2 acids (figure 7). However extractions always involve a serious decrease in sensitivity, while evaporation of the extract produces a solution in 0.1-0.5 ml of solvent, and only 1 pi of it can be brought in the gas chromatograph. Therefore work is in progress to enhance sensitivity by converting acids in­ to halogenated derivatives, which can be GC-analysed with the more sensitive electron-capture detector. For thiols a similar procedure is investigated as with aldehydes. One possibility is absorption of thiols in an alkaline solution and reaction with 2,4-dinitrochlorobenzene, yielding 2,4-dinitrofenylsulfides, which are analysed by HPLC (9). Sane improvements on removal of reagents at the one hand and on separation of sane by-products on the other hand have to be achieved in order to in­ crease the sensitivity with another factor of ten. 5. CONCLUSION The actual scope and limitations of chemical analysis of odour show that all problems can be tackled as far as emission is concerned. For iititiission measurements seme progress is necessary, but there is no essential reason why chemical analysis would be unable to attain the desired sensitivity for all types of odorants. There is no doubt that in a few years the last dif­ ficulties will be solved. In order to achieve real control of odour nui­ sance, automatic measurement is necessary on a long time basis. There again seme technical development is to be expected. Does this mean that machines are going to decide if an odour is pre­ sent or not? By no means, while the population will always be the reference, and psychophysical measurements will be necessary to make chemical analysis possible.

1986 ◽  
pp. 171-171
Keyword(s):  
Chemical Analysis ◽  
Quantitative Determination ◽  
Alkaline Solution ◽  
Automatic Measurement ◽  
The Other ◽  
Long Time ◽  
Time Basis ◽  
The One ◽  
By Products

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.

Optimising rational chemical analysis for quantitative determination of the composition of clay in soils

2018 ◽  
Vol 163 ◽  
pp. 153-163
Author(s):  
Tatyana Vakalova ◽  
Valeriy Pogrebenkov ◽  
Vladimir Vereshagin ◽  
Tamara Khabas ◽  
Inna Revva
Keyword(s):  
Chemical Analysis ◽  
Quantitative Determination

Quantitative Structural and Chemical Analysis of Thin Films: Part II

MRS Bulletin ◽  
1993 ◽  
Vol 18 (1) ◽  
pp. 21-23
Author(s):  
Y. Bruynseraede ◽  
Ivan Schuller
Keyword(s):  
Thin Films ◽  
Chemical Analysis ◽  
Quantitative Determination ◽  
Chemical Properties ◽  
Atomic Level ◽  
New Techniques ◽  
Comprehensive Review ◽  
Chemical Determination ◽  
And Chemical Properties

In the second of this two-part series for the MRS Bulletin, we present the most commonly used tools for the quantitative determination of structure and chemistry in thin films. The physics of thin films is at a stage during which one encounters phenomena that have a fragile dependence on the structure and chemical properties of the interface; the field, therefore, is at a stage during which quantitiative structural and chemical determination at the atomic level is a must. It is the purpose of the December and January issues of the Bulletin to provide a start for researchers interested in the field. Of course, even during the writing of these articles new techniques are being invented and it is therefore impossible to provide a comprehensive review of all techniques being used these days.

Quantitative Determination of Four Major Phases of Portland Cement by Combined X-Ray and Chemical Analysis

1959 ◽  
Vol 31 (9) ◽  
pp. 1521-1530 ◽  
Author(s):  
L. E. Copeland ◽  
Stephen. Brunauer ◽  
D. L. Kantro ◽  
E. G. Schulz ◽  
C. H. Weise
Keyword(s):  
Chemical Analysis ◽  
Portland Cement ◽  
Quantitative Determination ◽  
X Ray
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