analytical standards
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Detritus ◽  
2021 ◽  
pp. 30-41 ◽  
Author(s):  
Pierre Hennebert ◽  
Giovanni Beggio

This paper elucidates the theoretical principles behind the calculation of the size of a representative sample of granular solid waste. The key concept is the number of particles that must be present in a sub-portion of matter to be representative of a larger portion of matter. This depends on the fraction of particles in the waste batch showing the properties of interest, which shall be measured. A representative sample must include a fraction of particles of interest reliably similar to that of the waste batch to be characterized, with a controlled variability. In this context, it is demonstrated that the number of particles of interest that must be collected in a representative sample is 100. From this requirement, the mass of a representative sample can be calculated based on the knowledge of the frequency of particles of interest of the waste lot to be characterized. Data on particles concentrations in different samples of WEEE plastic scraps exemplifies how the presence in the sample of enough rare particles showing the property of interest is key to ensure reliable measurements. Further, the assumptions made on the controlled degree of variability to determine the minimum number of particles are discussed based on data on achievable intra- and inter-laboratory variability of analytical standards for waste characterization. Accordingly, the mass of laboratory samples and test portions recommended in published sampling plans or analytical standards are assessed for the occurring number of particles.


Synthesis ◽  
2021 ◽  
Author(s):  
Michael Sebald ◽  
Julian Gebauer ◽  
Matthias Koch

Abstract Alternariol (AOH) and alternariol-9-monomethyl ether (AME) are two secondary metabolites of Alternaria fungi which can be found in various foodstuff like tomatoes, nuts, and grains. Due to their toxicity and potential mutagenic activity the need for the development of high-throughput methods for the supervision of AOH- and AME-levels is of increasing interest. As the availability of both native and labeled AOH and AME analytical standards is very limited we herein wish to present a novel concise approach towards their synthesis employing a ruthenium-catalyzed ortho-arylation as the key step. Finally, we demonstrate their suitability as internal standards in stable-isotope dilution assay (SIDA)-HPLC-MS/MS analysis commonly used for the quantification of the natural products in food and feed.


2021 ◽  
Vol 12 ◽  
Author(s):  
Carni Lipson Feder ◽  
Oded Cohen ◽  
Anna Shapira ◽  
Itay Katzir ◽  
Reut Peer ◽  
...  

In the last decades, growing evidence showed the therapeutic capabilities of Cannabis plants. These capabilities were attributed to the specialized secondary metabolites stored in the glandular trichomes of female inflorescences, mainly phytocannabinoids and terpenoids. The accumulation of the metabolites in the flower is versatile and influenced by a largely unknown regulation system, attributed to genetic, developmental and environmental factors. As Cannabis is a dioecious plant, one main factor is fertilization after successful pollination. Fertilized flowers are considerably less potent, likely due to changes in the contents of phytocannabinoids and terpenoids; therefore, this study examined the effect of fertilization on metabolite composition by crossbreeding (-)-Δ9-trans-tetrahydrocannabinol (THC)- or cannabidiol (CBD)-rich female plants with different male plants: THC-rich, CBD-rich, or the original female plant induced to develop male pollen sacs. We used advanced analytical methods to assess the phytocannabinoids and terpenoids content, including a newly developed semi-quantitative analysis for terpenoids without analytical standards. We found that fertilization significantly decreased phytocannabinoids content. For terpenoids, the subgroup of monoterpenoids had similar trends to the phytocannabinoids, proposing both are commonly regulated in the plant. The sesquiterpenoids remained unchanged in the THC-rich female and had a trend of decrease in the CBD-rich female. Additionally, specific phytocannabinoids and terpenoids showed an uncommon increase in concentration followed by fertilization with particular male plants. Our results demonstrate that although the profile of phytocannabinoids and their relative ratios were kept, fertilization substantially decreased the concentration of nearly all phytocannabinoids in the plant regardless of the type of fertilizing male. Our findings may point to the functional roles of secondary metabolites in Cannabis.


2021 ◽  
Vol 18 (3) ◽  
pp. 419-445
Author(s):  
STEPHEN JOHNSON

AbstractKim Jong Il considered the 1971 premiere of the opera Sea of Blood a watershed moment in opera history. He lauded its innovative use of chŏlga (‘stanzaic song’) rather than aria and recitative. By Western analytical standards, however, chŏlga is simple and predictable, so scholars have thus far glossed over its conventions and their signification. This article instead argues that chŏlga conventions exhibit cultural hybridity and that Kim leveraged such hybridity to advocate a modern, popular, and national sound for North Korea. I begin by outlining hybrid characteristics of colonial-era popular music that chŏlga inherited. I then explore Kim's engagement with such trends in his speeches on chŏlga and demonstrate that cultural hybridity was central to his understanding of sonic modernity. Finally, I analyse a scene from Sea of Blood that pits chŏlga against other music genres, leading to a symbolic victory for the form and for the Korean nation.


Author(s):  
Akhilraj A.R ◽  
Rukmini S ◽  
Amalraj A.R

Background: Citraka or Sveta Citraka (Plumbago zeylanica L.) is an important medicinal plant mentioned in Ayurvedic classics, belongs to the family Plumbaginaceae. The root of the plant exhibits medicinal properties. It has a broad range of pharmacological activities, including anti-inflammatory, antibacterial, antifungal, anticancer, antidiabetic, antioxidant, hepatoprotective, wound healing and cytotoxic. Objective: The aim of the study was to evaluate phyto-pharmacognostical standardization with HPTLC fingerprinting of root of P. zeylanica, one of the most accepted and beneficial medicinal plant in Ayurveda. Materials and Methods: P. zeylanica was collected from Konni, Kerala, India during the month of May 2018 and its root was studied for macroscopic, microscopic, physico-chemical, preliminary phytochemical screening and HPTLC fingerprinting following the standard protocol recommended by The Ayurvedic Pharmacopoeia of India and Quality Standards of Indian Medicinal Plants. Results: The root is long, stout, cylindrical and reddish to dark brown in colour. The transverse section of root showed 5-7 rows of small cubical or rectangular celled cork with light yellow walls, polygonal or slightly tangentially elongated cortex cells containing starch grains and coloured contents, phloem containing small groups of fibres, radially arranged xylem vessels and narrow, 1-4 seriate medullary rays. Physico-chemical analysis showed water soluble extractive value as 26.11±0.01 w/w and alcohol soluble extractive value as 15.85±0.00 w/w. Preliminary phytochemical analysis of root decoction showed the presence of alkaloids, carbohydrates, tannins, saponins, resin and quinones. Conclusion: The information obtained from this research work may be useful to establish the botanical as well as analytical standards for the root of P. zeylanica.


2021 ◽  
Author(s):  
Wanessa A Ramsdorf ◽  
Eduarda Roberta Bordin ◽  
Renan cesar Munhoz ◽  
Paloma Pucholobek Panicio ◽  
Adriane Martins Freitas

Abstract Herbicide mixture is used as an alternative to obtain different mechanisms of action acting on weeds, resulting in the frequent presence of pesticides in environmental compartments. As they are products used worldwide, this study evaluated effects of environmentally relevant concentrations of the analytical standards and commercial formulations of the herbicides atrazine (2 µg L− 1) and glyphosate (65 µg L− 1), in isolation and also in mixture (2 + 65 µg L− 1) on the microcrustacean Daphnia magna. Through chronic exposure (21 days) of two generations of organisms, effects on survival and reproductive capacity were observed, as well as responses regarding oxidative stress, determined through the analysis of biochemical biomarkers such as catalase and glutathione S-transferase. In the evaluation of the first generation of test organisms, no significant results related to biochemical biomarkers were observed, only effects over sexual maturation of organisms. However, in the second generation of exposed organisms, changes were observed in all parameters evaluated, with the mixture of herbicide active principles being the treatment responsible for more significant responses (p < 0.05). A statistical difference (p < 0.05) was also observed between analytical standards and commercial formulations, indicating that other components present in the formulations can change the toxicity of the products. Given the difficulty of estimating the effects of mixtures and considering that various stressors are found in the environment, our results support the need to carry out studies that address long-term effects and, above all, that verify what the impacts are across generations, so that the toxicity of products is not underestimated.


Author(s):  
. Shyamala ◽  
Dongamanti Ashok

RP HPLC method was developed by this study estimation of favipiravir. This method is developed by Shimadzu LC -2010 HT by using a C18 (250 X 4.6 X mm X 5µ) column in solvents Water(OPA)+ACN  (60:40)v/v as mobile phase and the temperature was maintained at 25°C. The mobile phase flow rate of 1ml/min was pumped and sample wavelength was detected at 324 nm by ultraviolet -visible spectrophotometer. The Rt was found 4.453 min. The number of theoretical plates and tailing factor for favipiravir was observed 82651(NLT 2000) and 1.265 (NMT 2). The method was validated for analytical standards such as linearity, accuracy, precision, LOD, LOQ and robustness. LOD and LOQ values were calculated from regression of favipiravir 1.26 and 3.83 µg/ml.The regression equation of validated method for favipiravir is Y=253.5x+1881.In a wide range of 4 to 20 (µg/ml) the linearity was observed. Degradation methods were also performed.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4167
Author(s):  
Greta Petrella ◽  
Camilla Montesano ◽  
Sara Lentini ◽  
Giorgia Ciufolini ◽  
Domitilla Vanni ◽  
...  

A new strategy that takes advantage of the synergism between NMR and UHPLC–HRMS yields accurate concentrations of a high number of compounds in biofluids to delineate a personalized metabolic profile (SYNHMET). Metabolite identification and quantification by this method result in a higher accuracy compared to the use of the two techniques separately, even in urine, one of the most challenging biofluids to characterize due to its complexity and variability. We quantified a total of 165 metabolites in the urine of healthy subjects, patients with chronic cystitis, and patients with bladder cancer, with a minimum number of missing values. This result was achieved without the use of analytical standards and calibration curves. A patient’s personalized profile can be mapped out from the final dataset’s concentrations by comparing them with known normal ranges. This detailed picture has potential applications in clinical practice to monitor a patient’s health status and disease progression.


2021 ◽  
Vol 12 (2) ◽  
pp. 353-359
Author(s):  
Perera P A N G ◽  
Acharya Rabinarayan ◽  
Pandya P ◽  
Harisha C R ◽  
Shukla V J

Erythroxylum moonii Hochr. is a shrub or small tree in family Erythroxylaceae and folklore claims report the use of its leaves in the treatment of helminthiasis. Aim: Hence, present study aims to evaluate the pharmacognostic and analytical characters including HPTLC of its leaves. Methods: E. moonii fresh and powdered leaves were explored for the macroscopic and microscopic features along with their physico-chemical, phytochemical properties and HPTLC following standard procedures. Results: The leaf of E. moonii is simple, alternate, petiolate, stipulate, elliptic and lanceolate with obtusely caudate-acuminate apex, acute base and entire margins. Fresh leaf is light green, slight astringent with characteristic odour and smooth texture. Powdered dry leaves were light green, slight astringent with aromatic odour and coarse, fibrous texture. Microscopic evaluation revealed the presence of simple, bilobed and stellate trichomes (with and without lignification), rosette, rhomboidal, prismatic and cluster crystals, paracytic stomata and starch grains as key characteristics both in fresh leaves and powdered leaves. Obtained values for loss on drying, total ash, acid insoluble ash, pH, water and methanol soluble extractive were 10.44±0.31%, 2.2±0.67%, 0.93±0.06%, 5, 7.63±0.57% and 6.44±0.38% respectively. Qualitative phytochemical analysis suggested the presence of carbohydrates, steroids, glycosides, saponins, alkaloids, tannins and flavonoids in the test sample. HPTLC study revealed 17 and 11 peaks at short (254nm) and long (366nm) ultraviolet consecutively. Conclusion: Obtained results can be used to establish pharmacognostic and analytical standards of leaves of E. moonii which can serve as an important source to determine the quality, purity and strength of the powdered drug. 


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