An Improved Method for the Purification of Chlorophylls A and B; Quantitative Measurement of Their Absorption Spectra; Evidence for the Existence of a Third Component of Chlorophyll

1934 ◽  
Vol 95 (4) ◽  
pp. 529-562 ◽  
Author(s):  
F. Paul Zscheile,
Blood ◽  
1970 ◽  
Vol 36 (1) ◽  
pp. 98-110 ◽  
Author(s):  
AMOS S. DEINARD ◽  
ARTHUR R. PAGE

Abstract An improved method for doing DFP32 neutrophil survival studies is described that allows quantitative measurement of total circulating neutrophil-associated radioactivity. DFP32 labeled neutrophils are quantitatively trapped on a nylon fiber column and washed free of contaminating radioactivity. The neutrophil-associated radioactivity is then counted in a liquid scintillation counter. Data so obtained can then be used to construct both a true neutrophil survival curve and a curve for the fall-off of neutrophil specific activity. Leukokinetic data on hematologically normal individuals compare favorably with the values for normal persons that Athens and his collaborators have published.


1965 ◽  
Vol 9 ◽  
pp. 202-207
Author(s):  
B. S. Sanderson ◽  
L. E. MacCardle

AbstractThe normal procedure for a quantitative measurement of two phases with an X-ray diffractoraeter is to scan or count the intensities of two diffraction peaks and then to calculate the ratio of the two phases using an appropriate equation. This paper will describe an improved method of quantitatively measuring two phases in a sample. The diffractometer, which was constructed by Philips Electronics Instruments, consists of two fixed scintillation counters mounted at the Seeman-Bohlin focusing positions for the two desired diffraction lines. Each counter is preceded by a lithium fluoride curved crystal monochromator. The output from each counter feeds to a separate sealer which can be arranged to gate both sealers at a preselected number of counts. At this point a tape printer prints out the counts for both sealers. These counts are then related to the proportions of each phase present by an appropriate equation. Most of the electronics are solid-state designs. This paper will describe the instrumentation and show how it can be used to measure rapidly and precisely the ratio of anatase to rutile in a titanium dioxide system. The savings in time over the conventional method can be as much as 100 to 1.


1980 ◽  
Vol 28 (2) ◽  
pp. 127-134 ◽  
Author(s):  
J.W. Heringa ◽  
J. Groenwold ◽  
D. Schoonderbeek

The isolation of crop roots from soil samples, making use of the dispersing action of CO2 evolved by the reaction of added oxalic acid on carbonates in the soil was described. The roots were photographed in a thin layer of water against a matt black background, resulting in sharp negative pictures that can be used by a Quantimet image analyser to measure length or other properties embodied in the photographs. The methods were applied in a study of the rooting characteristics of potato crops in a rotation experiment. (Abstract retrieved from CAB Abstracts by CABI’s permission)


RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 109778-109785 ◽  
Author(s):  
Leila Hedayatifar ◽  
Elnaz Irani ◽  
Mahmood Mazarei ◽  
Soroush Rasti ◽  
Yavar T. Azar ◽  
...  

We report optical and electronic properties of the two main chlorophylls in green plants, namely, chlorophylls a and b. We estimate the electric moments of these molecules and study absorption spectra of the chlorophylls.


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