Penetapan Kadar Tanin pada Teh Hitam Kering Produksi Pekalongan dengan Metode Spektrofotometri UV-Vis

2021 ◽  
Vol 1 ◽  
pp. 905-914
Author(s):  
Nur Wijayanti ◽  
W Wirasti ◽  
Urmatul Waznah ◽  
Achmad Vandian Nur
Keyword(s):  
Black Tea ◽  
The Body ◽  
Good Effect ◽  
Tannin Content ◽  
Standard Curve ◽  
Qualitative Test ◽  
Curve Method ◽  
Standard Curve Method ◽  
The Difference ◽  
Tea Leaf

AbstractTea plants have benefits as antioxidants and help protect body cells from the bad effects of free radicals. The content in dried black tea leaves has tannin compounds that have a good effect on the body. The purpose of this study was to determine the difference in tannin levels in dry tea produced by Pekalongan with UV-Vis Spectrophotometry and to find out that all samples of tea brands met the requirements for consumption limits in tea. The data obtained were the average tannin content of black tea leaf extract from various samples with concentrations used of 8, 16, 24, 32, and 40 g/ml. Data analysis to determine the tannin content using the standard curve method, linear regression y = a + bx. The results obtained from the TLC qualitative test contained sample and comparison spots at UV 254 nm, namely Rf T1 of 0.84 cm, T2, T4, T5, T8, T9 of 0.85 cm, on samples T3, T7, T10, T11 obtained an Rf value of 0.86 cm which has the same Rf value as the comparison of catechins. and the sample T6 obtained an Rf value of 0.81 cm. As for the quantitative test, the highest levels were obtained in samples T1, T3, T6, T8, T10 as much as 0.004 ± 0 g/g while the lowest levels were obtained in samples T2, T4, T5, T7, T9, T11 as much as 0.003 ± 0 g/g It can be concluded that the circulating tannins produced by Pekalongan meet the consumption limit requirements.Keywords: Content; Tea; Tannins; UV-Vis Spectrophotometry AbstrakTanaman teh memiliki manfaat sebagai antioksidan dan membantu melindungi sel-sel tubuh dari efek buruk radikal bebas. Kandungan pada daun teh hitam kering mempunyai senyawa tanin yang memberikan efek baik bagi tubuh. Tujuan penelitian ini mengetahui adanya perbedaan kadar tanin pada teh kering produksi Pekalongan dengan metode Spektrofotometri UV-Vis dan mengetahui semua sampel merk teh memenuhi persyaratan batas konsumsi dalam teh. Data yang didapatkan adalah data rata-rata kadar tanin dari ekstrak daun teh hitam dari berbagai sampel dengan konsentrasi yang digunakan 8, 16,24, 32,dan40µg/ml. Analisis data untuk mengetahui kadar tanin dengan menggunakan metode kurva standar, regresi linier y = a + bx. Hasil yang diperoleh dari uji kualitatif KLT terdapat bercak noda sampel dan pembanding pada UV 254 nm, yaitu Rf T1 sebesar 0,84 cm , T2,T4,T5,T8, T9 sebesar 0,85 cm, pada sampel T3,T7,T10,T11 diperoleh nilai Rf sebesar 0,86 cm yang nilai Rf nya sama dengan pembanding katekin. dan pada sampel T6 diperoleh nilai Rf sebesar 0,81 cm. Adapun untuk uji kuantitatif nya diperoleh kadar tertinggi pada sampel T1, T3, T6, T8, T10 sebanyak 0,004 ± 0 g/g sedangkan kadar terendah diperoleh sampel T2, T4, T5, T7, T9, T11 sebanyak 0,003 ± 0 g/g, Hal ini dapat disimpulkan bahwa tanin yang beredar produksi Pekalongan memenuhi syarat batas konsumsi.Kata kunci: Kadar; Teh; Tanin; Spektrofometri UV-Vis

A Comparative Analysis of Methods for Titering Reovirus

2020 ◽  
Vol 8 (5) ◽  
pp. 409-417
Author(s):  
Yi-Chen Yang ◽  
Xian-Yao Wang ◽  
Yuan-Yuan An ◽  
Chun-Xiang Liao ◽  
Nian-Xue Wang ◽  
...  
Keyword(s):  
Traditional Method ◽  
Virus Titer ◽  
Cell Analysis ◽  
Half Cell ◽  
L929 Cells ◽  
Cell Index ◽  
Standard Curve ◽  
Analysis Technique ◽  
Curve Method ◽  
Standard Curve Method

Background: A key challenge in the process of virus amplification is the need for a simple and convenient method for measuring virus titers. Objective: Real-time unlabeled cell analysis (RTCA) was used to establish a standard curve of correlation between half-cell index time (CIT50) and virus titer. At the same time, the virus titer from tunable resistance pulse detection (TRPS) technology was compared with the traditional median tissue culture infectious dose (TCID50) method to evaluate the feasibility and application value of the RTCA technique and TRPS technology. Methods: : Cell index (CI) values for L929 cells under different culture conditions were detected, and the appropriate initial cell inoculation density was screened. The half-cell index (CI50) values of reovirus infected L929 cells with TCID50 titers were analyzed by RTCA, the CI50-TCID50 standard curve was created, and a regression equation was developed. RTCA, TCID50, and TRPS methods were used to detect the reovirus titer obtained by the amplification, and the sensitivity and feasibility of the CIT50-TCID50 standard curve method were analyzed. The virus titer was detected by TRPS technology and the TCID50 method. Results: L929 cells were best propagated at an initial density of 6 × 103 cells/well. After infecting L929 cells with different titers of reference reovirus, the linear correlation of CIT50 and TCID50 was y = -2.1806x + 71.023 (R2 = 0.9742). The titer resulting from the RTCA assay was 7×109.6821 pfu/mL, from the TRPS assay was 4.52×1010 pfu/mL, and from the TCID50 assay was 7×109.467 pfu/mL. Conclusion: The CIT50-TCID50 standard curve method established by the RTCA technique can be used to quantitatively detect reovirus titer with L929 cells. Compared with the TCID50 method, it takes a relatively short time and has high sensitivity and accuracy. The TRPS technology requires even less time to quantify the virus, but its precision is lower than that of the TCID50 method and RTCA technology. This study provides new technical methods for assessing the virulence of infectious live reovirus particles. Lay Summary: After amplification of the virus, we need to detect the virus titers (the virulence of the virus). The traditional method is to use the virus to infect cells, and then the virus titers can be calculated by 50% of the cells infected. However, this traditional method is time consuming. The ways of RTCA (a real-time cell analysis technique) and TRPS (a nano-bioparticle analysis technique) help us to detect viral titers. The consistency of these three methods determines their feasibility and accuracy. If they are feasible, then these two simple technologies will provide new ideas for detecting viral titers.

scholarly journals Ultra violet spectrophotometric analysis of Paracetamol, Diclofenac and Tramadol drugs in mixture

2019 ◽  
Vol 24 (3) ◽  
pp. 52
Author(s):  
Eesa M. Thalij1 ◽  
Sarhan A. Salman2 ◽  
, Hasan. M. Hasan1
Keyword(s):  
Limit Of Detection ◽  
Ultra Violet ◽  
Standard Addition ◽  
Spectrophotometric Analysis ◽  
Standard Curve ◽  
Limit Of Quantitation ◽  
Naoh Solution ◽  
Curve Method ◽  
Standard Curve Method ◽  
Tablet Dosage

The aim of this research was  develop and validate an analytical method by Uv spectrophotometric technique for quantitative determination of paracetamol (PAR), diclofenac or voltarine (DIC) and tramadol or tramal (TRA) in tablet dosage form, paracetamol analysis is based on the absorbance maxima were found to be at 243 nm when dissolved in 0.1N H2SO4 as a sample and in 0.1N NaOH solution as a blank,. Quantitative of PAR in sample is achieved by standard addition methods and three ways calculations were used to estimate the amount in the tablet, the expected content per tablet were equal to  (365.60, 361.984, 358.415 mg) and the results were acceptable when compared with original quantity in tablet(350 mg). The method was compared with standard curved method, showed that it is obeyed Beer – lambert law in the concentration range of 0.1–1 µg/ml for standard addition and standard curve methods, with a correlation coefficient of 0.9980 and o.9944. The limit of detection (LOD) for PAR was 0.036 µg/ml while limit of quantitation (LOQ) 0.119 µg/ml, the recovery of three procedure A, B, C of standard addition and standard curve were (104.40, 103.42, 102.40  and 92.995 %) for PAR ,it was found that the results obtained from the standard addition method were better than the result obtained from the standard curve method. The amount of (DIC) and (TRA) drug in tablet sample calculated depending on the  absorbance (A) at 273 nm to give the value 47.44 mg and 47.6 mg per tablet are acceptable when compared with the value of the original quantity in tablet (50mg) and the recovery of the method was found to be (95.2 and 96.0 % ) respectively, the principle of  the method based on the  (A) of mixture at this λ is a total A of the two drugs, which owns different intensity at this λ at different percentages and that apply to the sample and standard for this drugs. Finally this can applied successfully for routine analysis.    http://dx.doi.org/10.25130/tjps.24.2019.047

scholarly journals Impact of Amplification Efficiency Approaches on Telomere Length Measurement via Quantitative-Polymerase Chain Reaction

2021 ◽  
Vol 12 ◽  
Author(s):  
Waylon J. Hastings ◽  
Dan T. A. Eisenberg ◽  
Idan Shalev
Keyword(s):  
Telomere Length ◽  
External Validity ◽  
Single Copy ◽  
Amplification Efficiency ◽  
Logarithmic Scale ◽  
Single Copy Gene ◽  
Standard Curve ◽  
Copy Gene ◽  
Curve Method ◽  
Standard Curve Method

Background: Precise determination of amplification efficiency is critical for reliable conversion of within-sample changes in fluorescence occurring on a logarithmic scale to between-sample differences in DNA content occurring on a linear scale. This endeavor is especially challenging for the telomere length (TL) quantitative-PCR (qPCR) assay, where amplification efficiency can vary between reactions targeting telomeric repeats (T) and those targeting a single-copy gene (S) to calculate TL as the T/S ratio.Methods: We compared seven different approaches toward estimating amplification efficiency, including the standard-curve method utilized by the qPCR instrument software, and alternative approaches which estimate efficiency on a reaction-by-reaction basis using the stand-alone program LinRegPCR. After calculating T/S ratios using efficiency estimates from each approach (N = 363), we tested their relative performance on metrics of assay precision and correlates of external validity including chronological age (age range = 1–72 years), across tissues within-person (leukocyte-buccal), and between parents and offspring.Results: Estimated amplification efficiency for telomere reactions was significantly lower than estimates for single-copy gene reactions. Efficiency estimates for both reaction sets were significantly higher when estimated with the standard-curve method utilized by the qPCR instrument relative to estimates reconstructed during the log-linear phase with LinRegPCR. While estimates of single-copy gene efficiency reconstructed using LinRegPCR measured within 90% of perfect exponential doubling (E = 1.92), estimates generated using the standard-curve method were inflated beyond 100% (E = 2.10–2.12), indicating poor fidelity. Despite differences in raw value, TL measurements calculated with LinRegPCR efficiency estimates exhibited similar relationships with external validity correlates to measurements generated using the qPCR instrument software.Conclusion: Since methods to estimate amplification efficiency can vary across qPCR instruments, we suggest that future analyses empirically consider external methods of efficiency calculations such as LinRegPCR, and that already generated data be re-analyzed to glean possible improvements.

Exploring the formaldehyde reactivity of tannins with different molecular weight distributions: bayberry tannins and larch tannins

Holzforschung ◽  
2020 ◽  
Vol 74 (7) ◽  
pp. 673-682 ◽  
Author(s):  
Tao Yang ◽  
Mengqi Dong ◽  
Juqing Cui ◽  
Lu Gan ◽  
Shuguang Han
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Average Molecular Weight ◽  
Degree Of Polymerization ◽  
Standard Curve ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Curve Method ◽  
Standard Curve Method ◽  
Tannin Degradation

AbstractIn recent years, tannin degradation has been used to obtain tannin materials with an optimal molecular weight distribution (MWD) for synthesizing tannin-formaldehyde (TF) resin with high performance, but the optimal MWD of tannins is still unknown. The excellent formaldehyde reactivity of tannins is the basis for the synthesis of high-performance TF resin. Based on the formaldehyde reactivity of tannins, bayberry tannins and larch tannins were used to explore the optimal MWD of tannins for TF resin synthesis. Progressive solvent precipitation (PSP) was used to obtain tannin fractions with different MWDs. The formaldehyde reactivity of tannins was determined using the modified Stiansy method combined with the standard curve method (GB/T 17657-2013). The bayberry tannin fraction [weight-average molecular weight (Mw) of acetylated tannin: 4115, mean degree of polymerization (mDP): 6.64] and the larch tannin fraction (Mw of acetylated tannin: 3906, mDP: 5.84) had the best formaldehyde reactivity. Furthermore, significant differences in the formaldehyde reactivity of condensed tannins (CTs) with different MWDs were observed. The obtained results can be used to purposefully degrade tannins to achieve an optimal MWD, which is beneficial for the production of TF adhesives with high performance.

Atomic Absorption Determination of Nickel in Heavy Crudes via Carbon Rod Atomizer

1977 ◽  
Vol 31 (3) ◽  
pp. 207-210 ◽  
Author(s):  
J. J. Labrecque ◽  
J. Galobardes ◽  
M. E. Cohen
Keyword(s):  
Atomic Absorption ◽  
Standard Curve ◽  
Determination Of Nickel ◽  
Absorption Determination ◽  
Relative Standard ◽  
Curve Method ◽  
Standard Additions ◽  
Standard Curve Method ◽  
Carbon Rod Atomizer

A method is described for the determination of nickel in heavy crude oil by carbon rod atomic absorption spectroscopy in the parts per million range. A 5-g sample is completely dissolved to 25 ml of tetrahydrofuran (THF) stabilized with 0.1% hydroquinone and further diluted with THF. Nickel can be measured at a concentration of 0.1 ppm with a relative standard deviation of about 10% after a 100-fold dilution of the crude. The analysis by standard curve method as well as standard additions methods gave reproducible results. These results also agreed well with values obtained by conventional activation analysis. The method is relatively rapid after sample dilution.

Molecular mechanisms underlying the synergistic interaction of the novel anticancer drug celandine with gemcitabine in preclinical models of pancreatic cancer.

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 233-233
Author(s):  
N. Funel ◽  
E. Giovannetti ◽  
M. Del Chiaro ◽  
L. Pollina ◽  
F. Mosca ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cultures ◽  
Untreated Control ◽  
Molecular Mechanisms ◽  
Rna Extraction ◽  
Standard Curve ◽  
Gene Transcripts ◽  
Curve Method ◽  
Standard Curve Method

233 Background: Celandine (Ukrain) increased median survival in combination with gemcitabine compared to gemcitabine alone (10.4 vs. 5.2 months; p<0.001) in unresectable PDAC (Gansauge et al.; Langenbecks Arch Surg 2002). There is compelling evidence that gene transcripts of determinants of gemcitabine activity could be used to tailor PDAC chemotherapy (Giovannetti et al., Cancer Res 2006). Methods: In vitro studies were performed in two ATCC cell lines (PL45 and Mia PaCa-2) and two primary cell cultures obtained from PDAC patients who underwent surgical resections (PPTCC78 and PPTCC109). Cells were treated with celandine at IC50concentration levelsfor 48 h. The total RNA extraction was performed with TRIzol protocol. All the amplifications were carried out with normalization of gene expression against the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) housekeeping control gene, and the quantitation of gene expression was performed using the direct ratio, the standard curve method and the ΔΔCT calculation, in which the amount of target, normalized to the endogenous control and relative to the calibrator (untreated control cells) was calculated as 2(-ΔΔCt). Results: Celandine positively modulates the expression of hENT1 mRNA in all PDAC cell cultures treated with IC50 (p<0.001). The 2(-ΔΔCt) analysis revealed a mean increase of 2.8-fold (p=0.001) with respect to untreated control cells. In PL45 and Mia PaCa-2 cells celandine positively affects mRNA expression of dCK gene as well. Conclusions: To date a few options based on gemcitabine are available for treatment of PDAC. Most gemcitabine-based chemotherapy regimens resulted in a very limited disease control, and studies attempting to widen the therapeutic armamentarium against this disease are warranted. Based on the previous clinical data the celandine-gemcitabine combination appears a promising regimen and the results of the present study provide the experimental basis for the further clinical testing of the celandine-gemcitabine schedule in PDAC patients. No significant financial relationships to disclose.

scholarly journals Determination of the Correction Factor for Dinalmefene Hydrochloride in Nalmefene Hydrochloride Injection

2019 ◽  
Vol 267 ◽  
pp. 03001
Author(s):  
Tianyi Zhao ◽  
Ziqing Liu ◽  
Furao Guo ◽  
Peiyu He ◽  
Hongyu Zhang ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Correction Factor ◽  
High Performance ◽  
Limit Of Quantification ◽  
Sample Concentration ◽  
Standard Curve ◽  
Curve Method ◽  
Standard Curve Method ◽  
Impurity Detection

Objective: To calculate the detection correction factor for the impurity, that is, the dinalmefene hydrochloride in nalmefene hydrochloride injection. Methods: High performance liquid chromatography (HPLC) is used to analyze the impurities of nalmefene hydrochloride easily produced during storage, and the impurity is determined and correction factor is calculated for the known the dinalmefene hydrochloride. According to the standard curve method, the sample concentration is selected between the detection limit and the limit of quantification, and the standard curve is prepared. The correction factor is then calculated according to the slope of the standard curve. Results: finally, the correction factor for dinalmefene hydrochloride is 0.22. Conclusions: the correction factor calculated by the standard curve method is accurate and reliable, and can be used for impurity detection of nalmefene hydrochloride injection.

Discrimination and Simultaneous Determination of 6-BA and KT by Polarized Synchronous Light Scattering and Synchronous Light Scattering Spectrum

2013 ◽  
Vol 634-638 ◽  
pp. 81-86
Author(s):  
Xiao Hui Zhao ◽  
Qian Hua Zhu ◽  
Qiong Yang ◽  
Wei He ◽  
Shang Zhou ◽  
...  
Keyword(s):  
Light Scattering ◽  
Simultaneous Determination ◽  
Buffer Solution ◽  
Standard Curve ◽  
Scattering Spectrum ◽  
Curve Method ◽  
Standard Curve Method ◽  
Novel Method ◽  
Light Scattering Spectrum

In pH=5.70 B-R buffer solution, Na2WO4 and rhodamine 6G（R6G） could react with natural cytokinins of 6-benzylaminourine (6-BA) and kinetin (KT) and resulted in a great enhacement of synchronous light scattering (SLS) signals. This article first established the degree of polarized synchronous light scattering (P) based on the measurements of the polarized synchronous light scattering signals to distinguish two natural cytokinins of 6-BA and KT. Simultaneously based on the synchronous scattering spectrum and the double standard curve method, a novel method for simultaneous determination of 6-BA and KT was developed by SLS spectralmethod. The method was applied to simultaneous determination of 6-BA and KT in balsam pear skin and tomato skin with satisfactory results.

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