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Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 305
Author(s):  
Willy Cely-Veloza ◽  
Diego Quiroga ◽  
Ericsson Coy-Barrera

Fusarium oxysporum is an aggressive phytopathogen that affects various plant species, resulting in extensive local and global economic losses. Therefore, the search for competent alternatives is a constant pursuit. Quinolizidine alkaloids (QA) are naturally occurring compounds with diverse biological activities. The structural diversity of quinolizidines is mainly contributed by species of the family Fabaceae, particularly the genus Lupinus. This quinolizidine-based chemo diversity can be explored to find antifungals and even mixtures to address concomitant effects on F. oxysporum. Thus, the antifungal activity of quinolizidine-rich extracts (QREs) from the leaves of eight greenhouse-propagated Lupinus species was evaluated to outline promising QA mixtures against F. oxysporum. Thirteen main compounds were identified and quantified using an external standard. Quantitative analysis revealed different contents per quinolizidine depending on the Lupinus plant, ranging from 0.003 to 32.8 mg/g fresh leaves. Bioautography showed that all extracts were active at the maximum concentration (5 µg/µL). They also exhibited >50% mycelium growth inhibition. All QREs were fungistatic except for the fungicidal QRE of L. polyphyllus Lindl. Angustifoline, matrine, 13α-hydroxylupanine, and 17-oxolupanine were ranked to act jointly against the phytopathogen. Our findings constitute reference information to better understand the antifungal activity of naturally afforded QA mixtures from these globally important plants.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yang Xu ◽  
Yuejie Wang ◽  
Shengnan Bi ◽  
Yanxue Jia ◽  
Huiwei Bao

Objective. To establish a quantitative analysis of multicomponents by single marker (QAMS) method for the simultaneous determination of 4 active components such as protocatechuic acid, catechin, quercetin, and luteolin in Plantago depressa. Method. 4 active components in Plantago depressa were studied. Quercetin was used as an internal reference to establish the relative correction factors among protocatechuic acid, catechin, and luteolin and calculate the contents of each component; the results were compared with those measured by the external standard method. Results. 4 components showed a good linear relationship in their respective concentration ranges (r > 0.9995). The relative correction factors (fs/k) of protocatechuic acid, catechin, and luteolin were 1.1992, 0.8613, and 1.6069, respectively. The method had good durability. The contents of protocatechuic acid, catechin, and luteolin calculated by QAMS were not significantly different from those measured by the external standard method. Conclusion. QAMS can be used to determine the content of 4 components in Plantago depressa at the same time, and the method is simple, accurate, and can be used for quality control.


EKSPLORIUM ◽  
2021 ◽  
Vol 42 (2) ◽  
pp. 149
Author(s):  
Neneng Laksminingpuri Sanusi ◽  
Moch Faizal Ramadhani ◽  
Nurfadhlini Nurfadhlini ◽  
Lies Aisyah

ABSTRAK. Telah dilakukan penentuan komposisi bahan bakar nabati (BBN) dalam bahan bakar minyak campuran (BBMC) dengan metode direct counting C-14. Penentuan komposisi BBN dalam BBMC dilakukan dengan cara memipet 10 mL BBMC ke dalam vial gelas kemudian ditambahkan 10 mL larutan sintilator Ultima Gold F (UGF) ke dalamnya. Vial tersebut dikocok agar campuran menjadi homogen kemudian dicacah menggunakan LSC (Liquid Scintillation Counter) Elmer Perkin 2900TR selama 20 menit sebanyak 30 siklus. Hasil pencacahan ditampilkan dalam bentuk tSIE (transformed external standard spectrum) dan cpm (cacahan permenit). Hasil analisis memperlihatkan nilai cpm yang meningkat seiring kenaikan persentase BBN dalam BBMC. Nilai cpm terendah dan tertinggi untuk sampel bensin, avtur, dan solar berturut-turut adalah 14,2363 dan 62,0343, 10,664 dan 44,535, serta 9,410 dan 61,789. Terdapat korelasi kuat antara nilai tSIE dan nilai cpm pada bensin dan solar tapi tidak pada avtur. Hasil analisis terhadap sampel uji menunjukkan bahwa sampel tersebut berada di luar grafik deret sampel. Metode direct counting ini diharapkan dapat menjadi referensi dalam uji mutu BBMC.ABSTRACT. The composition of biofuel (BF) in mixed oil fuel (MOF) has been determined using the C-14 direct counting method. Determination of the composition of BF in MOF was carried out by pipetting 10 mL of BBMC into a glass vial and then adding 10 mL of Ultima Gold F (UGF) scintillator solution into it. The vial was shaken so that the mixture became homogeneous and then counted using the Elmer Perkin 2900TR LSC (Liquid Scintillation Counter) for 20 minutes for 30 cycles. The results of the counting are displayed in the form of tSIE (transformed external standard spectrum) and cpm (counts per minute). The results of the analysis show that the value of cpm increases with the increase in the percentage of BF in MOF. The lowest and highest cpm values for gasoline, avtur, and diesel samples were 14.2363 and 62.0343, 10.664 and 44.535, and 9.410 and 61.789, respectively. There is a strong correlation between tSIE and cpm values for gasoline and diesel but not for avtur. The results of the analysis of the test sample indicate that the sample is outside the sample series graph. This direct counting method is expected to be a reference in the BBMC quality test.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haibin Lu ◽  
Xueyang Zhang ◽  
Shakeel Ahmad Khan ◽  
Wenqiang Li ◽  
Lei Wan

In this study, we propose to synthesize NPs using plant extract containing active biomedical components, with the goal of obtaining NPs that inherit the biomedical activities of the plant. Herein, we report the synthesis of manganese dioxide nanoparticles (VBLE-MnO2 NPs) using the leaves extract of Viola betonicifolia, in which the biological active plant’s secondary metabolites function as both reducing and capping agents. The synthesized NPs were successfully characterized with different spectroscopic techniques. The antibacterial, antifungal, and biofilm inhibition properties of the synthesized VBLE-MnO2 NPs were further explored against a variety of bacteria (Gram-positive and Gram-negative) and mycological species. Additionally, their antioxidant ability against linoleic acid peroxidation inhibition, cytobiocompatibility with hMSC cells, and cytotoxicity against MCF-7 cells were investigated compared to leaves extract and chemically synthesized manganese dioxide NPs (CH-MnO2 NPs). The results were demonstrated that the synthesized VBLE-MnO2 NPs presented excellent antibacterial, antifungal, and biofilm inhibition performance against all the tested microbial species compared to plant leaves extract and CH-MnO2 NPs. Moreover, they also exhibited significant antioxidant potential, which was comparable to the external standard (ascorbic acid); however, it was higher than plant leaves extract and CH-MnO2 NPs. Furthermore, the synthesized CH-MnO2 NPs displayed good cytobiocompatibility with hMSC cells compared to CH-MnO2 NPs. The enhanced antioxidant, antibacterial, antifungal, and biofilm inhibition efficacy as compared to CH-MnO2 NPs might be attributed to the synergistic effect of the VBLE-MnO2 NPs’ physical properties and the adsorbed biologically active phytomolecules from the leaves extract of V. betonicifolia on their surface. Thus, our study establishes a novel ecologically acceptable route for nanomaterials’ fabrication with increased and/or extra medicinal functions derived from their herbal origins.


2021 ◽  
pp. 13-18
Author(s):  
Сергей Вячеславович Черепица ◽  
Светлана Николаевна Сытова ◽  
Антон Николаевич Коваленко ◽  
Лидия Николаевна Соболенко ◽  
Евгений Дмитриевич Шевченко ◽  
...  

Для обеспечения надлежащего качества и безопасности алкогольной продукции перед поставкой ее потребителям выполняется определение количественного содержания летучих компонентов. Данный контроль выполняют на газовых хроматографах. Количественный расчет значений концентраций выполняют по методу внешнего стандарта и по методу внутреннего стандарта. Метод внешнего стандарта используется в межгосударственных стандартах: ГОСТ 30536-2013, ГОСТ 31684-2012, ГОСТ 33833-2016, ГОСТ 33834-2016, ГОСТ 33408-2015, ГОСТ 31684-2012 и в государственных стандартах ГОСТ Р 52363-2005 и СТБ ГОСТ Р 51698-2001. С целью достижения высокой достоверности получаемых данных при контроле качества и безопасности алкогольной продукции, уменьшения материальных, финансовых и трудовых затрат предложен инновационный метод, заключающийся в использовании этилового спирта, содержащегося в испытуемом образце, в качестве внутреннего стандарта. Эффективность метода продемонстрирована на примере сравнительного анализа результатов определения количественного содержания летучих компонентов в широком спектре алкогольной продукции, выполненного по используемому в настоящее время методу внешнего стандарта и по предложенному методу. Показано, что для валидации метода и последующего его внедрения в практику испытательных лабораторий не требуется каких-либо дополнительных материальных, финансовых или трудовых затрат. To ensure the proper quality and safety of alcoholic beverages, the quantitative content of volatile compounds is determined before delivery to consumers. This control is performed on gas chromatographs. The quantitative calculation of the concentration values is carried by external and internal standard methods. The external standard method is used in standards: GOST 30536-2013, GOST 31684-2012, GOST 33833-2016, GOST 33834-2016, GOST 33408-2015, GOST 31684-2012 and in state standards GOST R 52363-2005 and STB GOST R 51698-2001. In order to achieve high reliability of the data obtained when controlling the quality and safety of alcoholic beverages, and to reduce material, financial and labor costs, an innovative method is proposed. This method is based on using ethyl alcohol, contained in the test sample, as an internal standard. The effectiveness of the method is demonstrated by the example of a comparative analysis of the results of determining the quantitative content of volatile compounds in a wide range of alcoholic beverages, performed according to the currently used external standard method and according to the proposed method. It is shown that for validation the method and its subsequent implementation into the practice of testing laboratories does not require any additional material, financial or labor costs.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Feng Xuehua ◽  
Zhou Guangjiao ◽  
Tao Ali

Methods. The influences of methanol proportion, flow rate, column temperature, and injection volume in the mobile phase on the chromatographic resolution of chromatographic peak of euphorbia factor L1 were experimentally studied via Plackett–Burman design, and the key analysis parameters were screened out; the key analysis parameters were optimized through the central composite design, and the chromatographic analysis conditions were established. Euphorbia factor L1 was taken as the internal reference to construct the relative correction factors for L3 and L4 relative to L1, and their contents were calculated, thus realizing the QAMS. Meanwhile, the euphorbia factor L3 and euphorbia factor L4 were determined using the external standard method, and the differences of values measured by the external standard method from the values predicted by the QAMS method were compared, in an effort to verify the accuracy and feasibility of the QAMS method. Results. The methanol proportion and column temperature in the mobile phase were the key analysis parameters P < 0.05 , and the chromatographic conditions were determined as follows. The methanol/water ratio, column temperature, detection wavelength, flow rate, and injection volume were 60 : 40, 30°C, 275 nm, 1.0 mL/min, and 10 μL, respectively. A total of 20 batches of samples were determined by the QAMS method and external standard method; the relative standard deviations (RSDs) of L3 and L4 determination results were less than 2.0%, without any significant difference. Conclusion. The QbD-based QAMS method can be used to determine the contents of euphorbia factor L3 and euphorbia factor L4 in Euphorbia lathyris L., and it is accurate and feasible.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Li Yong ◽  
An-Qin Leng ◽  
Zhi-Xiang Yang ◽  
Ying Xue

Nucleosides can be used as quality evaluation indicators of Tricholoma matsutake. In this work, a new ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS) strategy for quantitative analysis of multiple components using a single marker (QAMS) was proposed to determine nine nucleosides (adenosine, cytidine, guanosine, inosine, uridine, 2′-deoxyadenosine, 2′-deoxycytidine, 2′-deoxyguanosine, and 2′-deoxyuridine) in T. matsutake. Guanosine was set as the internal reference substance, whose content in T. matsutake was determined using the conventional external standard method. Relative correction factors (RCFs) between guanosine and eight other nucleosides were measured. The concentrations of the eight components were calculated with the obtained RCFs by QAMS. An ultrasonic extraction method is used for sample preparation. This method was validated to be sensitive, precise, and accurate with the LODs of 0.31–1.9 ng, the overall intraday and interday variations less than 4.08%, and the overall recovery over 89.0%. The correlation coefficients (r2) of the calibration curves were higher than 0.9918. The values of vector angle analysis were above 0.99845, which indicates no significant differences between the conventional external standard method and the present QAMS method. As far as we know, this is also the first report of UPLC/MS analysis of nucleoside compounds by QAMS, providing an efficient and feasible quality assessment method for other natural products containing nucleosides.


Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5374
Author(s):  
Ruru Ren ◽  
Yanting Li ◽  
Huan Chen ◽  
Yingli Wang ◽  
Lingling Yang ◽  
...  

Given the standard substances of zeaxanthin and its homologues obtained from Lycium barbarum L. (LB) are extremely scarce and unstable, a novel quantitative analysis of carotenoids by single marker method, named QAMS, was established. Four carotenoids including lutein, zeaxanthin, β-carotene, and zeaxanthin dipalmitate were determined simultaneously by employing trans-β-apo-8′-carotenal, a carotenoid component which did not exist in LB, as standard reference. Meanwhile, β-carotene, another carotenoid constituent which existed in LB, was determined as contrast. The QAMS methods were fully verified and exhibited low standard method difference with the external standard method (ESM), evidenced by the contents of four carotenoids in 34 batches of LB samples determined using ESM and QAMS methods, respectively. HCA, PCA, and OPLS-DA analysis disclosed that LB samples could be clearly differentiated into two groups: one contained LB samples collected from Ningxia and Gansu; the other was from Qinghai, which was directly related to the different geographical location. Once exposed under high humidity (RH 75 ± 5%) at a high temperature (45 ± 5 °C) as compared with ambient temperature (25 ± 5 °C), from day 0 to day 28, zeaxanthin dipalmitate content was significantly decreased, and ultimately, all the decrease rates reached about 80%, regardless of the storage condition. Our results provide a good basis for improving the quality control of LB.


F1000Research ◽  
2021 ◽  
Vol 9 ◽  
pp. 1030
Author(s):  
Luigi Marongiu ◽  
Eric B. Shain ◽  
Marianna Martinelli ◽  
Matteo Pagliari ◽  
Heike Allgayer

Background: Accurate viral load (VL) determination is paramount to determine the efficacy of anti-HIV-1 therapy. The conventional method used, fit-point (FP), assumes an equal efficiency in the polymerase chain reaction (PCR) among samples that might not hold for low-input templates. An alternative approach, maxRatio, was introduced to compensate for inhibition in PCR. Methods: Herein, we assessed whether maxRatio could improve VL quantification using 2,544 QIAgen artus HI virus-1 RT-PCR reactions. The assay’s standard dilutions were used to build external standard curves with either FP or maxRatio that re-calculated the VLs. Results: FP and maxRatio were highly comparable (Pearson’s ρ=0.994, Cohen’s  κ=0.885), and the combination of the two methods identified samples (n=41) with aberrant amplification profiles. Conclusions: The combination of maxRatio and FP could improve the predictive value of the assay.


2021 ◽  
Vol 3 (1) ◽  
pp. 107-113
Author(s):  
ZH Shar ◽  
OP Pirhot ◽  
HH Shar ◽  
MK Channa

Milk is an essential component of human food, and natural source of many important elements. Besides essential elements it is also became a source of toxic metals due to heavy environmental pollution. In order to assess the essential metals (calcium) and toxic metals (cadmium and lead) in milk, sixty different fresh milk samples were analyzed by using atomic absorption spectroscopy (AAS). Accuracy and precession were checked by external standard addition method. Calcium was found in all samples with highest concentration (24µg/L) in camel milk. Lead was found in all milk samples with mean level 3.14µg/L and highest concentration found in packed milk sample 6.7µg/L. Cadmium was detected in 33% of total samples analyzed with range of (1.1-3.1µg/L). Results of this study will be helpful in setting the standards in one of the most consumed commodities in Pakistan.


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