The boron determination of some plant materials as determined with and without adding CaO before ashing

1967 ◽  
Vol 26 (1) ◽  
pp. 202-204 ◽  
Author(s):  
Umesh C. Gupta
Author(s):  
Grażyna Kowalska

The presented study was aimed at the determination of the level of contamination with heavy metals (Cd, Pb, As, and Hg) in 240 samples of plant materials, i.e., herbal raw materials, spices, tea, and coffee. Moreover, a probabilistic risk assessment (noncarcinogenic and carcinogenic risks) was estimated by models including target hazard quotient (THQ) and cancer risk (CR). The samples were subjected to microwave mineralisation with the use of HNO3 (65%), while the determination of the content of the elements was performed with the use of inductively coupled plasma mass spectrometer (ICP–MS) and a mercury analyser. The element which was characterised by the highest level of accumulation in the analysed samples was lead (from 0.010 to 5.680 mg/kg). Among the heavy metals under analysis, the lowest concentration was noted in the case of mercury (from 0.005 to 0.030 mg/kg). A notably higher level of contamination with heavy metals was noted in the analysed samples of herbs and spices (0.005–5.680 mg/kg), compared to samples of tea and coffee (0.005–0.791 mg/kg). According to the guidelines of the World Health Organisation (WHO) concerning the limits of contamination of samples of herbal raw materials with heavy metals, lead levels exceeding the limits were only noted in 24 samples of herbs (18%). In all of the analysed samples of spices, tea, and coffee, no instances of exceeded limits were noted for any of the analysed heavy metals. The values of TTHQmax (in relation to the consumption of the analysed products) were as follows: up to 4.23 × 10−2 for spices, up to 2.51 × 10−1 for herbs, up to 4.03 × 10−2 for China tea, and up to 1.25 × 10−1 for roasted coffee beans. As the value of THQ ≤1, there is no probability of the appearance of undesirable effects related to the consumption of the analysed group of raw materials and products of plant origin. The CR value for As (max. value) was 1.29 × 10−5, which is lower than the maximum acceptable level of 1 × 10−4 suggested by United States Environmental Protection Agency (USEPA).


2000 ◽  
Vol 889 (1-2) ◽  
pp. 83-91 ◽  
Author(s):  
Anne-Christine Schmidt ◽  
Werner Reisser ◽  
Jürgen Mattusch ◽  
Peter Popp ◽  
Rainer Wennrich

2020 ◽  
Vol 31 (2) ◽  
pp. 88-92
Author(s):  
Vladimir Mikhailovich Koldaev ◽  
Artem Yurevich Manyakhin ◽  
Petr Semenovich Zorikov

AbstractThis paper aims at spectrophotometric determination of changes in stability of extractable anthocyanins during drying of plant materials depending on their color. Raw and dried colored parts of 50 plant species from 25 families were used for the study. The extracts were prepared over 95% ethanol acidified with hydrochloric acid (pH ~ 1). The absorption spectra were registered within the range of 210 to 680 nm. The extinction variability factor, coefficient of intensity absorption relative and generalized stability factor were used to determine the anthocyanin degradation. The highest values of the stability factor were obtained for the extracts from fruit shells of burgundy or violet color within the range of 0.934±0.024 to 0.973±0.024, while the extracts from flower petals of the same care featured the stability factor that was 1.19 to 1.44 times less. The values of the stability factor of the extracts from black, red and blue materials are 1.15 to 1.19 times, 1.74 to 2.48 times and 4.65 to 4.84 times less respectively than those of the extracts from violet-burgundy materials. It is appropriate to apply the spectrophotometric factors of anthocyanins stability used in this study to selection of promising plants for industrial cultivation as material of anthocyanin-containing herbal preparations. The most stable anthocyanins are those of burgundy-purple and black fruits.


Author(s):  
M. F. Zayats ◽  
S. M. Leschev

Based on the distribution constants of biphenazate, obtained experimentally and also calculated from literature data on the solubility of biphenazate in water and organic solvents, as well as experimental data on the extraction of biphenazate from plant matrices by various extractants, we selected the optimal conditions for extracting biphenazate from apples and cucumbers. The conditions for the purification of the extracts were also selected. Acetonitrile in the presence of ammonium sulfate and hexane was used for extraction of the pesticide. Purification of extracts of plant materials was carried out by partitioning between hexane and water-acetonitrile mixture. The samples obtained after this treatment were pure enough to determine the residual amounts of biphenazate in them at the maximum residue level determined in Belarus and the countries of the European Union, or lower using widespread liquid chromatography with diode-array (ultraviolet) detection.


2011 ◽  
Vol 94 (5) ◽  
pp. 1383-1390
Author(s):  
Bharathi Avula ◽  
Yatin J Shukla ◽  
Yan-Hong Wang ◽  
Ikhlas A Khan

Abstract An HPLC method was developed for the quantitative determination of five pregnane derivatives from aerial parts of Caralluma species and dietary supplements. The method was validated for linearity, repeatability, LOD, and LOQ. The LOD and LOQ of five pregnane compounds were found to be in the range of 1–5 and 3–15 μg/mL, respectively, by HPLC using photodiode array detection. This method was applied to the identification of three plant materials of Caralluma species (C. fimbriata, C. umbellate, and C. attentuata) and seven dietary supplements claiming to contain C. fimbriata. An LC/MS coupled with electrospray ionization interface method was used for the identification of compounds and involved the use of [M+Na]+ ions in the positive ion mode with extracted ion chromatogram.


1929 ◽  
Vol 12 (1) ◽  
pp. 133-135
Author(s):  
J T Sullivan ◽  
L E Horat
Keyword(s):  

1995 ◽  
Vol 78 (5) ◽  
pp. 1189-1194 ◽  
Author(s):  
Joseph M Betz ◽  
Kevin D White ◽  
Ara H Der Marderosian

Abstract The bark of Pausinystalia yohimbe [K. Schumann] Pierre (Rubiaceae), long valued as an aphrodisiac in West Africa, recently has been promoted in the United States as a dietary supplement alternative to anabolic steroids for enhancement of athletic performance. As the number of yohimbe products on the retail market increases, concerns about their safety are raised because of the reported toxicity of yohimbine (the major alkaloid of the plant). Although plant materials are usually identified microscopically, we were unable to identify them in many of the products, because as their labels indicated, the products were mixtures of various bo-tanicals or were bark extracts and contained little or no plant material. A method for extraction and capillary gas chromatographic (GC) separation of the alkaloids of P. yohimbe was, therefore, developed and used to analyze a number of commercial yohimbe products. The method involved solvent extraction and partitioning in chloroform–water followed by separation on a methyl silicone capillary GC column (N–P detection). Comparisons of chromatograms of extracts of authentic bark with those of commercial products indicated that, although many products contained measurable quantities of the alkaloid yohimbine, they were largely devoid of the other alkaloids previously reported in this species. Concentrations of yohimbine in the commercial products ranged from <0.1 to 489 ppm, compared with 7089 ppm in the authentic material. Authentic bark has been reported to contain up to 6% total alkaloids, 10–15% of which are yohimbine. The possible presence of undeclared diluents in the products was indicated by peaks in product chromatograms but not in those of authentic bark.


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