scholarly journals DERIVATIVE SPECTROPHOTOMETRY FOR NO3- DETERMINATION IN SANITARY SEWAGES

2020 ◽  
Vol 28 ◽  
pp. 579-583
Author(s):  
Tayane Cristiele Rodrigues Mesquita ◽  
Pamela Lais Cabral Silva ◽  
Lucas Rafael Lommez Vaz ◽  
Alisson Carraro Borges

The objective of this study was to observe the feasibility of using the UV spectrophotometric method of the second derivative in the determination of nitrogen in the form of nitrate in sanitary sewers, since this method is indicated for water with low content of organic matter. Therefore, the results obtained in that method were compared with the salicylate methodology. The Mann-Whitney test showed a significant difference (? = 5%) between the results obtained in both methods. However, when compared, the difference between them was less than 0.25 mg L-1 in half of the observations. Despite this significant difference, the use of the second derivative method for sanitary sewage samples showed satisfactory performance.

2017 ◽  
Vol 100 (5) ◽  
pp. 1392-1399 ◽  
Author(s):  
Nada S Abdelwahab ◽  
Nehal F Fared ◽  
Mohamed Elagawany ◽  
Esraa H Abdelmomen

Abstract Stability-indicating spectrophotometric, TLC-densitometric, and ultra-performance LC (UPLC) methods were developed for the determination of mepivacaine HCl (MEP) in the presence of its toxic impurity, 2,6-dimethylanaline (DMA). Different spectrophotometric methods were developed for the determination of MEP and DMA. In a dual-wavelength method combined with direct spectrophotometric measurement, the absorbancedifference between 221.4 and 240 nm was used for MEPmeasurements, whereas the absorbance at 283 nm was used for measuring DMA in the binary mixture. In the second-derivative method, amplitudes at 272.2 and 232.6 nm were recorded and used for the determination of MEP and DMA, respectively. The developed TLC-densitometric method depended on chromatographic separation using silica gel 60 F254 TLC plates as a stationary phase and methanol–water–acetic acid (9 + 1 + 0.1, v/v/v) as a developing system, with UV scanning at 230 nm. The developed UPLC method depended on separation using a C18 column (250 × 4.6 mm id, 5 μm particle size) as a stationary phase and acetonitrile–water (40 + 60, v/v; pH 4 with phosphoric acid) as a mobilephase at a flow rate of 0.4 mL/min, with UV detection at 215 nm. The chromatographic run time was approximately 1 min. The proposed methods were validated with respect to International Conference on Harmonization guidelines regarding precision, accuracy, ruggedness, robustness, and specificity.


Author(s):  
AHMED M AL-GHANI ◽  
ANES AM THABET

Objectives: The aim of this work was to develop and validate new, simple, accurate, and selective spectrophotometric methods (derivative and derivative ratio spectrophotometric methods) for the determination of these drugs. These methods can be used as analytical tools in routine examination in quality control laboratories. Methods: The first method was derivative method in which the first derivative method (1D) for determination of PCM and the second derivative method (2D) for determination of CIN. The second method was the first derivative ratio spectrophotometric method (1DD) for determination of CIN and PCM. Results: In first method, the first derivative spectrum (1D) of PCM where PCM was determined by measuring the amplitude of the valley at 235 nm while CIN showed zero crossing spectrum, and the second derivative spectrum (2D) of CIN where CIN was determined by measuring the amplitude of the peak at 287.5 nm while PCM showed a zero value. In the second method, the first derivative ratio spectrophotometry (1DD) for CIN and PCM determination, where the amplitude at 290 and 291 nm, was selected for the determination of CIN and PCM, respectively. Conclusions: The developed methods were applied for the determination of the cited drugs in tablets containing binary drug mixture. The methods are simple and precise and can be used for routine analysis of the labeled drugs in combined dosage forms in quality control laboratories.


2019 ◽  
Vol 10 (1) ◽  
pp. 12-18
Author(s):  
Nessreen Salah Abdelhamid ◽  
Eglal Abdelhamid Abd El Aleem El Aleem ◽  
Aml Mohamed Khorshed ◽  
Mahmoud Mohsen Amin

An accurate, sensitive and time saving spectrophotometric method has been developed and validated for the determination of two antihypertensive drug mixtures. Mixture 1 contains spironolactone (SPIR), furosemide (FUR) and anthranilic acid (ANTH) (impurity of furosemide) and mixture 2 contains triamterene (TRI), hydrochlorothiazide (HCZ) and chlorothiazide (CZ) (impurity of hydrochlorothiazide). In mixture 1, the determination of drugs depends on dividing the spectrum of ternary mixture by the spectrum of 10 µg/mL of standard furosemide and then spironolactone and anthranilic acid were determined using the difference in amplitude between 242.3 and 254.6 nm, and between 250.8 and 242.4 nm in the ratio spectrum, respectively. On the other hand, furosemide could be determined by dividing the spectrum of ternary mixture by the spectrum of 10 µg/mL of standard spironolactone and then it was determined using the difference in amplitude between 244.8 and 229.7 nm in the ratio spectrum. In mixture 2, the determination of drugs depends on dividing the spectrum of ternary mixture by spectrum of 10 µg/mL of standard triamterene and then hydrochlorothiazide and chlorothiazide were determined using the difference in amplitude between 268.9 and 232.8 nm, and between 292.9 and 250.7 nm in the ratio spectrum, respectively. On the other hand, triamterene could be determined by dividing spectrum of ternary mixture by spectrum of 10 µg/mL of standard hydrochlorothiazide and then triamterene was determined using the difference in amplitude between 230.1 and 244 nm in the ratio spectrum. The developed analytical methods were validated regarding good accuracy and precision according to The International Conference on Harmonisation guidelines, and they were applied to pharmaceutical preparations in addition to laboratory prepared mixtures successfully. Statistically the results were compared with those obtained by reported method and no significant difference was found.


Author(s):  
Mouhammed Khateeb ◽  
Basheer Elias ◽  
Fatema Al Rahal

A simple and sensitive kinetic spectrophotometric method has been developed for the determination of folic acid (FA) in bulk and pharmaceutical Formulations. The method is based on the oxidation of FA by Fe (III) in sulfuric acid medium. Fe (III) subsequently reduces to Fe (II) which is coupled with potassium ferricyanide to form Prussian blue. The reaction is followed spectrophotometrically by measuring the increase in absorbance at λmax 725 nm. The rate data and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1–20 μg mL-1 for each method. The correlation coefficient was 0.9978 and 0.9993, and LOD was found to be 0.91 and 0.09 μg mL-1 for rate data and fixed time methods, respectively. The proposed method has been successfully applied to the determination of FA in formulations with no interference from the excipients. Statical comparison of the results shows that there is no significant difference between the proposed and pharmacopoeial methods


2002 ◽  
Vol 30 (4) ◽  
pp. 1379-1384 ◽  
Author(s):  
Maryam Kazemipour ◽  
Ebrahim Noroozian ◽  
Mohammad Saber Tehrani ◽  
Massoud Mahmoudian

2019 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Aisyah Aisyah

This research is experimental research on students class XI of MIPA in SMA Negeri 3 Purwokerto. This research takes the title of "The Influence of the Application of the Cooperative Learning Model Type Course Review Horay (CRH) Against the Liveliness of learning and the Results of the Economic Study (study on the Grade XI MIPA in SMA Negeri 3 Purwokerto)". The purpose of this research is to know the difference in learning outcomes and learning activity between the learning model Course Review Horay (CRH) with conventional learning model, to know the influence of learning model Course Review Horay (CRH) against the learning outcomes and learning activity, as well as to know the influence of the liveliness of the learning results of learning. The population of this research is the grade XI MIPA in SMA Negeri 3 Purwokerto. The number of samples taken in this study is 72 i.e. 2 Class XI of MIPA which each class amounted to 36 students. Purposive Sampling Method used in the determination of the sample. Based on the results of the research and the anallisis data indicate that (1) there is a significant difference between the model of learning learning activeness cooperative Course Review Horay (CRH) and conventional learning model on economics. (2) there are significant differences between the learning outcomes learning model cooperative Course Review Horay (CRH) and conventional learning model on economi. (3) there is a positive influence learning model cooperative Course Review Horay (CRH) against the liveliness of the study on economic. (4) there is a positive influence learning model cooperative Course Review Horay (CRH) against the results of the study on economic. (5) there is no positive influence between the liveliness of student learning against the results of the study on economic. Penelitian ini adalah penelitian eksperimen pada siswa kelas XI MIPA di SMA Negeri 3 Purwokerto. Penelitian ini mengambil judul “Pengaruh Penerapan Model Pembelajaran Kooperatif Tipe Course Review Horay (CRH) terhadap Keaktifan Belajar dan Hasil Belajar Ekonomi (Studi pada Siswa Kelas XI MIPA di SMA Negeri 3 Purwokerto)”.        Tujuan dari penelitian ini adalah untuk mengetahui perbedaan keaktifan belajar dan hasil belajar antara model pembelajaran Course Review Horay (CRH) dengan model pembelajaran konvensional, untuk mengetahui pengaruh model pembelajaran Course Review Horay (CRH) terhadap keaktifan belajar dan hasil belajar, serta untuk mengetahui pengaruh keaktifan belajar terhadap hasil belajar. Populasi penelitian ini adalah siswa kelas XI MIPA di SMA Negeri 3 Purwokerto. Jumlah sample yang diambil dalam penelitian ini adalah 72 yaitu 2 kelas XI MIPA yang masing-masing kelas berjumlah 36 siswa. Purposive Sampling Method digunakan dalam penentuan sample. Berdasarkan hasil penelitian dan anallisis data menunjukkan bahwa (1) Terdapat perbedaan signifikan keaktifan belajar antara model pembelajaran kooperatif Course Review Horay (CRH) dengan model pembelajaran konvensional pada mata pelajaran ekonomi. (2) Terdapat perbedaan signifikan hasil belajar antara model pembelajaran kooperatif Course Review Horay (CRH)  dengan model pembelajaran konvensional pada mata pelajaran ekonomi. (3) Terdapat pengaruh positif model pembelajaran kooperatif Course Review Horay (CRH)  terhadap keaktifan belajar pada mata pelajaran ekonomi. (4) Terdapat pengaruh positif model pembelajaran kooperatif Course Review Horay (CRH)  terhadap hasil belajar pada mata pelajaran ekonomi. (5) Tidak terdapat pengaruh positif antara keaktifan belajar siswa terhadap hasil belajar pada mata pelajaran ekonomi.  


2021 ◽  
Author(s):  
Fang Bao ◽  
Ming Cui ◽  
Xiuying Shi ◽  
Shaoqing Ju ◽  
Hui Cong

Abstract Background: Homocysteine (Hcy) is considered to be an independent risk factor for cardiovascular and cerebrovascular diseases. No study has evaluated the distribution of Hcy on a large-scale health examination. Accordingly, this study aimed to investigate the level and distribution of Hcy in the healthy physical examination population and the correlation with other biomarkers, and analyzed for cardiovascular and other diseases. The prevention provides an important scientific basis.Methods: From February 2017 to April 2020, 8063 medical examination populations were selected for analysis. Determination of serum Hcy, TC, TG, LDL-c, HDL-c, ALT, ALP, γ-GT, TBIL, GLU, urea, Cr, UA and related metabolic risk factors. According to the multivariate regression model of age, gender, smoking, drinking, body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure (DBP), the relationship between Hcy and other biochemical indicators was evaluated. Results: Among 8063 cases, the age, BMI, SBP and DBP of the high-Hcy group were higher than those of the low-Hcy group, the difference was statistically significant (P<0.05), and the proportion of males, smoking and drinking were higher than the low In the Hcy group, the difference was statistically significant (P<0.05); the ALT, ALP, γ-GT, TBIL, Urea, Cr, UA, and TG in the high Hcy group were higher than those in the low Hcy group, and the difference was statistically significant (P<0.05 ); HDL-c in the high-Hcy group was lower than that in the low-Hcy group, and the difference was statistically significant (P<0.05). There was no statistically significant difference in TC, LDL-c, and GLU between the high- and low-Hcy groups (P>0.05). In multivariate analysis, lnHDL-C was negatively correlated with lnHcy (β=-0.038, SE=0.016, P<0.05), lnCr was positively correlated with lnHcy (β=0.055, SE=0.016, P<0.05), lnUA and lnHcy were positive correlation (β=0.043, SE=0.019, P<0.05). Conclusion: Hcy is closely related to HDL-c, Cr and UA, which indicates that Hcy may affect the metabolism of HDL-c and UA, and can also be used as an auxiliary diagnostic index for kidney injury.


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