scholarly journals Inorganic chemical analysis of plant tissue: possibilities and limitations.

1986 ◽  
Vol 34 (4) ◽  
pp. 449-456
Author(s):  
V.J.G. Houba ◽  
I. Novozamsky ◽  
J.J. van der Lee
Keyword(s):  
Chemical Analysis ◽  
Sharp Increase ◽  
Plant Material ◽  
Plant Materials ◽  
Analytical Results ◽  
Inorganic Chemical ◽  
Low Levels ◽  
Using Data ◽  
Inorganic Components

The variability of analytical results for determination of 23 inorganic components in different plant materials was evaluated, using data obtained over the last 5 years of an extensive (on the average 120 participants) bimonthly collaborative interlaboratory study. In particular, the relation between content level and coefficient of variation (CV) was examined. Usually, a constant CV value was found at high content levels, with a sharp increase in CV at low levels. The precision found for N, P, K, Ca, Cl, Mg, Zn and nitrate was high enough (CV < 20%) to yield reasonably comparable content values. Comparison of analytical results for B, Cu, Fe, Cd, Mn and Na, may be difficult, since about 20% CV was already reached at the levels usually present in plant material. The analytical results for Al, Co, Cr, Mo, Ni, Pb, S, Se and sulphate varied considerably, irrespective of the content level, which means that comparable results are very hard to produce with these components. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Distribution patterns of polyphenols and alkaloids in instant coffee, soft and energy drinks, and tea

2013 ◽  
Vol 31 (No. 5) ◽  
pp. 483-500 ◽  
Author(s):  
N. Manchón ◽  
L. Mateo-Vivaracho ◽  
D. Arrigo M ◽  
A. García-Lafuente ◽  
E. Guillamón ◽  
...  
Keyword(s):  
Black Tea ◽  
Distribution Patterns ◽  
Energy Drinks ◽  
Soft Drinks ◽  
Instant Coffee ◽  
Different Types ◽  
Low Levels ◽  
Using Data ◽  
Phytochemical Profiles

A previously developed method of HPLC-DAD-Fl has been used for the determination of phytochemical profiles in different types of drinks: instant coffee, soft drinks, energy drinks, and different types of tea (green, white, black, and red tea). Using data on the concentrations of 20 main phytochemicals (phenolic acids, flavan-3-ols, flavonols, flavones, and alkaloids) it was possible to identify most of the sample types. Chlorogenic and caffeic acids, and caffeine are the main target compounds in instant coffee; in soft and energy drinks, only caffeine was found. Tea has a more complex phytochemical composition. Unfermented tea is mainly composed of flavan-3-ols and alkaloids, with a high caffeine concentration. Black tea is composed of alkaloids and low levels of flavan-3-ols, which are affected by oxidative reactions during the fermentation. Flavonols are present in lower concentrations in all kinds of teas. The identified phytochemical distribution patterns were used to correctly differentiate instant coffee, soft drinks, energy drinks, unfermented tea and fermented tea (within fermented tea, black tea from red tea can also be differentiated).

Validation of Automated Library-Based Qualitative Screening of Pesticides by Comprehensive Two-Dimensional Gas Chromatography/Time-of-Flight Mass Spectrometry

2011 ◽  
Vol 94 (6) ◽  
pp. 1722-1740 ◽  
Author(s):  
Hans G J Mol ◽  
Henk van der Kamp ◽  
Guido van der Weg ◽  
Martijn van der Lee ◽  
Arjen Punt ◽  
...  
Keyword(s):  
Quantitative Methods ◽  
Time Of Flight ◽  
Added Value ◽  
Two Dimensional ◽  
False Negatives ◽  
Plant Materials ◽  
Flight Mass Spectrometry ◽  
Fit For Purpose ◽  
Low Levels ◽  
Using Data

Abstract A method for automated detection and reporting of pesticides in plant materials based on comprehensive two-dimensional GC/time-of-flight MS with library-based detection by software has been developed and validated. Optimum settings for detection parameters such as spectral match threshold and first and second dimension retention time tolerances were assessed with respect to occurrence of false detects and false negatives. Next the method was validated following European Union guidelines established for qualitative screening of pesticides. The validation was largely done in retrospect by using data obtained for spiked samples (235 pesticides, various crops, 0.01–0.2 mg/kg) that had been analyzed previously with routine samples over a period of 18 months. At 0.01 mg/kg, the required 95% confidence level (&lt;5% false negatives) was met for 83 compounds. This increased to 185 compounds at the 0.2 mg/kg level. For a number of pesticides, especially at low levels, it had to be concluded that at this stage the method was not fit-for-purpose to reliably demonstrate the absence of pesticides in samples to be analyzed. On the other hand, the fact that the overall detection rate at 0.01 mg/kg was 71% clearly showed that the method does provide added value for the numerous pesticides that are not covered by quantitative methods because the infrequent occurrence does not justify inclusion in such methods.

BIOEFFICACY OF PLANT EXTRACTS AGAINST MUSTARD APHID AND THEIR NATURAL ENEMIES

2019 ◽  
Vol 25 (1) ◽  
Author(s):  
NARENDRA SINGH ◽  
N. S. BHADAURIA ◽  
PRADYUMN SINGH
Keyword(s):  
Plant Extracts ◽  
Natural Enemies ◽  
Untreated Control ◽  
Plant Material ◽  
Aphid Population ◽  
College Of Agriculture ◽  
Mustard Aphid ◽  
Plant Materials

The Bio-efficacy of eleven plant extracts namely viz.Neem Kernel; Rhizome of Ginger; Leaves of Datura, Gajarghas, Harsingar, Oak and Latjeera; Bulb of Garlic and Onion; Flowers of Chrysenthemum and Fruits of Chilli in the concentration of 5 percent and imidacloprid @ 40 g ai/ha was tested against mustard aphid, Lipaphiserysimi and their effect on D. rapae and Coccinellid beetle were tested in the Department of Entomology, College of Agriculture, Gwalior (M.P.). All the tested plant materials and imidacloprid @ 40 g ai/ha were effective significanty in reducing the aphid population over control.The aphid population in treated plots ranged from 7.2 to 40.0 as against 85.4 aphid/twig in untreated control. Among the plant material, three sprays of Neem Kernel were found most effective followed by three sprays of chilli fruits.All the plant extracts were found significantly safer to D. rapae and coccinellid bettle in comparision to insecticide (imidacloprid).

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