2023-05

International Journal of Environmental Science and Technology

This study aimed to investigate the potential of potato peel waste powder as a biomass feedstock for hydrothermal carbonization to produce hydrochar, which could be used as an adsorbent for water treatment. An autoclave was used at 200 °C for 25 h to prepare potato peel hydrochar from potato peel waste powder and compare their physicochemical properties using various characterization techniques. The results showed that potato peel hydrochar had a higher specific surface area and adsorption capacity for Congo red than potato peel waste powder, making it a viable adsorbent for water treatment. The experimental data were well-fitted with the Freundlich isotherm and pseudo-second-order kinetic models, suggesting that the adsorption process at the solid/solution interface is spontaneous, endothermic, and more disordered. The study highlights the potential of waste biomass, such as potato peel, to produce hydrochar as an effective and sustainable adsorbent for water treatment.

2023-03

New Journal of Chemistry (Issue : 16) (Volume : 47)

Nanozymes, as an alternative to natural enzymes, have the advantages of good catalytic efficiency, high stability, easy storage, low-cost, and the ability to be used under extreme conditions compared with natural enzymes. Improving the sensitivity of nanozyme-based assays is highly required and depends on the nanozyme size, chemical structure and morphology. In the present work, an oxidase-mimicking nanozyme of MnO2 sub-microspheres was synthesized from KMnO4 and MnCl2·4H2O via a one-step hydrothermal method followed by calcination for 2 h at 300 °C. The oxidase-like activity of the sub-microspheres was evaluated through the conversion of 3,3′,5,5′-tetramethylbenzidine (TMB; colorless) to (ox-TMB (blue color). The kinetic results showed that the catalytic behavior of the MnO2 sub-microspheres follows Michaelis–Menten kinetics with a low constant (Km = 0.1 mM) compared with the natural enzyme HRP (Km = 0.434 mM). The catalytic mechanism was deduced, whereby the oxidase-mimicking behavior is dependent on the formation of O2˙− radicals and partially dependent on OH˙ radicals. An efficient colorimetric platform capable of sensitive determination of ascorbic acid was developed based on fading of the blue color of ox-TMB by ascorbic acid. The linear detection range was from 1.0 to 100 μM, and the limit of detection was 0.33 μM. The proposed method showed high selectivity and sensitivity for the detection of ascorbic acid. Further applications in real samples were also successfully demonstrated.

2022-11

AIP publishing (Issue : 1) (Volume : 2660)

Safe quality of drinking water is a critical concern for human health. Bardarash is one of the districts of Duhok city located in the Kurdistan Region in the north part of Iraq and considered a rich area of oil resources. Groundwater wells are the main sources of drinking water in this area. To date, no study has focused on examining the quality of drinking water in Bardarash district. The aim of this study is to assess the physic-chemical quality of drinking water in this area. Water samples were collected from local wells (103) from four subjoined districts and analyzed for 10 heavy metals and physico-chemical parameters using atomic spectroscopy and standard methods. The results showed that most of the heavy metals and physico- chemical analysis values were below the permissible limits set by WHO, while few values were higher for Al, Fe, Cr, NO31- and TAL. The data also show significant variation (P<0.05) of the physico-chemical parameters and some heavy metals among four subjoined districts. It can be concluded that the water samples were not highly contaminated although water treatment with regular monitoring and periodic cleaning of domestic tanks is required to obtain sustainable clean drinking water in this area.

2022-09

International Journal of Environmental Analytical Chemistry (Issue : 15) (Volume : 102)

In this study, monometallic (Ni) and bimetallic (Ni-Ag) nanoparticles were synthesised by a bio reduction approach using Cicer Arietinum leaf extract which is known to contain high amount of phenolic and flavonoid compounds that can serve as nano-bio sources for synthesis metallic NPs. Biosynthesised nanoparticles were characterised using various techniques viz UV-Vis, FE-SEM, EDX, and XRD. The average crystallite diameter was found to be 30 nm and 24 nm for NiNPs and Ni-AgNPs, respectively, with almost spherical shapes, regular morphology and homogenously formed. The synthesised NPs were successfully applied for adsorption of toluidine blue dye (TBO) in aqueous solution using batch experiments with different process parameters namely initial dye concentration, contact time, pH, adsorbent dosage, and temperature. The adsorption isotherms and kinetics were investigated in detailed; the results followed Freundlich model (R2 = 0.990, 0.976) and pseudosecond- order kinetic (R2 = 0.998, 0.999) for both mono and bimetallic NPs, respectively. Finally, adsorption process showed that bimetallic Ag-NiNPs (qe = 94 mg g−1) could be considered mor

2022-07

Analytical Biochemistry (Issue : 114818) (Volume : 654)

In nanozyme-based assays, increasing enzymatic activity is very desirable for enhancing sensitivity and lowering the detection limit. In this study, novel Mn doped cobalt oxide nanosheets (Mn@Co3O4 NSs) were synthesized by hydrothermal process. The obtained Mn@Co3O4 possessed enhanced dual-enzyme mimetic, oxidase and peroxidase, and can catalytically oxidize of 3, 3′ , 5, 5′ -tetramethylbenzidine (TMB), to a blue product of oxidized TMB. The enzyme kinetics were well-described mathematically using a common Michaelis-Menten and Lineweaver Burk model. The enzyme kinetics constant (Km) was found to be 0.15 mM, which is relatively low comparing with pure Co3O4 nanosheets (0.35 mM) and natural enzyme HRP (0.434 mM). Therefore, the efficient colorimetric method was achieved for determination of H2O2 and ascorbic acid. The limit of detection (LOD) of H2O2 was 8.0 μM and the linear range was 20–200 μM based on direct turn on of the peroxidase-like activity of Mn@Co3O4. While, for ascorbic acid detection based on turn-off approach, the linearity range for the ascorbic acid was 1–8 μM with LOD of 0.4 μM. Moreover, the colorimetric system exhibited good stability and selectivity toward the detection of ascorbic acid effectively in real samples (vitamin C tablets) with satisfactorily accuracy and precision.

2021-03

Science journal of university of Zakho (Issue : 1) (Volume : 9)

ABSTRACT: A nanodrop spectrophotometric method was developed and validated for determination of amlodipine besylate (AB) in bulk and tablet dosage form. The maximum absorption of amlodipine was shown at 357 nm using acetonitrile as a solvent. The developed method was found to be linear (R2 = 0.9990) within the concentration range of 2-10 μg/mL. The precision study showed acceptable values of RSD% (less than 1%). LOD and LOQ values were found to be 0.34 and 1.14 μg/mL, respectively. Accuracy study showed good recovery 99% Awalodipine and 98.88% Amloneer, in locally commercial tablets. The present method was applied successfully for stability indicating study of AB inA walodipine and Amloneer products manufacturedi n (Erbil and sulaymaniyah, respectively)/ Kurdistan of Iraq. The stability -indicating study was investigated under acidic, basic, o xidative, photolytic, and thermal conditions. The results of both products showed that AB is unstable in acidic, alkaline, and oxidative conditions under heating at 60℃ up to 5 hr.s While under photolytic and thermal conditions, the degradation percentagwe as less than 15% indicating to the stability of AB in both Awalodipine and Amloneer tablets according to International Conference on Harmonization (ICH) guideline of drugs. It can be concluded that the main factor that affects the degradation of AB is the passage of time.

2020-07

Asian Journal of Applied Chemistry Research (Issue : 2) (Volume : 6)

This study involves a development method for spectrophotometric analysis of sulfamethoxazole (SMZ) with vanillin reagent in acidic medium. The reaction mechanism was proposed by Schiff's base reaction of the amine group in SMZ with the carbonyl group in vanillin. The spectrum of SMZ complex showed high absorbance at 399.09 nm following the Beer–Lambert law in the concentration levels ranging from 5 to 80 μg.mL-1 with good sensitivity. The stability constant of the product was determined. The values of relative standard deviation (≤ 6.63) and recovery (> 98.73%) indicated a reasonably precise and accurate method with a good limit of detection and quantification. The present method was compared with other spectrophotometric methods in the literature. The procedure of the method showed to be simple since no need for temperature control and solvent extraction. The suggested method was used to determine of SMZ in commercial pharmaceutical drops and compared with the certified method

2019-06

International Journal of Pharmaceutical Sciences and Research (Issue : 1) (Volume : 10)

Fixed-dose combinations have several advantages comparing with a single drug and separate agents. For simple dosing regimens and their synergistic antihypertensive action, a combination of hydrochlorothiazide and losartan potassium is widely prescribed. In this study, an HPLC-UV method was developed and validated for the simultaneous determination of hydrochlorothiazide and losartan in bulk and pharmaceutical formulation. The method was optimized selecting chromatographic conditions of 60: 40 acetonitrile: water, ACE3-C18 column (250 mm × 4.6 mm 5 µm), 20 µl injection volume, the flow rate of 1 ml/min at ambient temperature (25 °C), and 226 nm. The method was validated giving good precision (RSD% < 1), acceptable linearity (R2 ≥ 0.997), and low LOD and LOQ (0.5 and 1.5 µg/ml, respectively). Successful application on pharmaceutical dosage tablet form gave recovery percent within acceptance criteria (92% and above) indicating that the proposed method is simple and reliable for the determination of LOP and HCTZ and hence can be applied for routine analysis in quality control laboratories.

2019-06

sjuoz (Issue : 2) (Volume : 7)

The present study was designed to optimize the adsorption of arsenic onto potato peel derived activated carbon (MPP-AC) by employing response surface method and central composite design. Adsorbent of cheap and locally available potato residue was produced based on chemical activation with H3PO4 subsequently carbonization to produce the porous activated carbon. The individual and interactive effects of five variables including initial arsenic concentration, temperature, time, dosage amount and pH of the medium were investigated. Based on the statistical analysis (ANOVA), the quadratic model was developed associating the adsorption capacity (qe). The optimum conditions were obtained of 9.98 mg L-1 of initial As (V) concentration, 28 °C of temperature, 39.7 min of time, 0.97 g of adsorbent dose and 7.3 of pH. The maximum adsorption capacity was 0.27 mg g-1 and 76.5% removal efficiency. The equilibrium isotherms and kinetic studies for estimating the mechanism of process demonstrated a good fit to Langmuir model and the pseudo-second order, respectively. The results of this study showed that the feasibility of central composite design (CCD) to control adsorption process and indicated the use of activated carbon of potato residue have important implications for As (V) removal.

2019-01

International Journal of Pharmaceutical Sciences and Research, (Issue : 1) (Volume : 10)

Fixed-dose combinations have several advantages comparing with a single drug and separate agents. For simple dosing regimens and their synergistic antihypertensive action, a combination of hydrochlorothiazide and losartan potassium is widely prescribed. In this study, an HPLC-UV method was developed and validated for the simultaneous determination of hydrochlorothiazide and losartan in bulk and pharmaceutical formulation. The method was optimized selecting chromatographic conditions of 60: 40 acetonitrile: water, ACE3-C18 column (250 mm × 4.6 mm 5 μm), 20 μl injection volume, the flow rate of 1 ml/min at ambient temperature (25 °C), and 226 nm. The method was validated giving good precision (RSD% < 1), acceptable linearity (R2 ≥ 0.997), and low LOD and LOQ (0.5 and 1.5 μg/ml, respectively). Successful application on pharmaceutical dosage tablet form gave recovery percent within acceptance criteria (92% and above) indicating that the proposed method is simple and reliable for the determination of LOP and HCTZ and hence can be applied for routine analysis in quality control laboratories.

2017-09

Science journal of university of Zakho (Issue : 3) (Volume : 5)

Pollution of wastewater with heavy metal has always been a serious problem to the environment. Chromium is considered one of the most noxious heavy metals. Adsorption is now reorganized as an alternative technology of defence for chromium removal due to local availability, technical efficiency and cost effectiveness. Potato peel powder can be used as a low cost biosorbent to remove hexavalent chromium from aqueous solutions under various experimental conditions. Different parameters including equilibrium contact time, initial metal ion concentration, potato peel dose, pH and temperature were studied through a number of batch sorption experiments. Both the Langmuir and Freundlich were found to fit the adsorption isotherm of Cr (VI) ion onto potato peel. The Langmuir adsorption capacity was found to be 1.97 mg/g while Freundlich constants including Kf and n were 1.57 and 2.5, respectively. The adsorption kinetic was found to be more fit with the pseudo-first order model. This study showed a high efficiency of potato peel for the biosorption of Cr (VI) ion from aqueous solutions.

2017-06

International Journal of Pharmaceutical Sciences and Research (Issue : 6) (Volume : 8)

A reverse phase high performance liquid chromatography (RP-HPLC) method was developed and validated for the determination of Atenolol (ATN) in bulk and pharmaceutical formulation. The method was optimized selecting chromatographic conditions of 60: 40 acetonitrile: water, Inertsil_ column(ODS-3 250 mm × 4.6 mm 5 𝜇m), 20 𝜇L injection volume, flow rate of 1 mL/min at ambient temperature (30 °C), and 276 nm. Using two HPLC systems of first HPLC system coupled with PDA detector and the second HPLC system coupled with UV detector showed no big difference in the method results. The method was validated giving good precision (RSD% < 1), acceptable linearity (R2 > 0.998), and low LOD and LOQ (0.5 and 1.5 𝜇g/mL, respectively) on both systems. Successful application on pharmaceutical dosage tablet form gave high recovery of 97.7%. The proposed method is economic, simple, and rapid and hence can be employed for routine analysis in quality control laboratories.

2016-08

Chromatography Research International (Issue : 2016) (Volume : 2016)

An HPLC-PDA method was developed and validated for the determination of hydrochlorothiazide in bulk and pharmaceutical formulation.Themethod was optimized selecting chromatographic conditions of 50 : 50 acetonitrile :water, Inertsil column(ODS- 3 250mm × 4.6mm 5 𝜇m), 20 𝜇L injection volume, flow rate of 1 mL/min at ambient temperature (30∘C), and 272 nm. Another column of C18Zorbax (Eclipse Plus, 4.6 × 250 mm, 5 𝜇m) was tested showing no big difference in the method results.The method was validated giving good precision (RSD% < 1), acceptable linearity (𝑅 2 ≥ 0.9978), and low LOD and LOQ (0.5 and 1.7 𝜇g/mL, resp.) on both columns. Successful application on pharmaceutical dosage tablet form gave high recovery of 99.93%. The method was compared with official BP and other reported methods.The proposed method is economic, simple, and rapid and hence can be employed for routine analysis in quality control laboratories.

2016-07

Indian Journal of Materials Science (Issue : 2016) (Volume : 2016)

Theadsorption behaviour of aromatic amine 3-chloroaniline (3-CA) fromaqueous solution on fresh potato skin was investigated. A series of batch experimentswere conducted under different experimental conditions of contact time, 3-chloroaniline concentration, weight of potato skin, pH, temperature, and ionic strength using RP-HPLC analysis. Adsorption equilibrium of 3-chloroaniline at concentration of 10 𝜇g/mL on 1 g weight of chopped potato skin was achieved in 24 hours. Using different varieties of potato skin showed that the adsorption of 3-CA on Nicola variety is higher compared to Sante and Maris Peer varieties. Adsorption on potato skin was found to be generally higher compared to cortex and pith tissues. Analysis of adsorption isothermshows that equilibrium data was fitted to Freundlich model (𝑅 2 = 0.977). Maximum adsorption capacities of 3-chloroaniline were found in the pH range from3 to 9,whereas lowadsorption quantitieswere found in high acidic and high basic solutions (pH 2 and pH13, resp.).Adsorption capacity increased with an increase in temperature from 4∘C to 30∘C but decreased with further increase of temperature to 40∘C. Testing the ionic strength showed that increasing the concentration of electrolyte reduces the adsorption efficiency. This study indicated that the fresh potato skin (without any treatment) is possible to use as a new adsorbent for removal of 3-chloroaniline from industrial waste water.

2015-06

Eur. Chem. Bull. (Issue : 8) (Volume : 4)

Simple, sensitive and reproducible spectrophotometric method was developed for estimation of oxymetazoline hydrochloride via charge transfer complex formation reaction. The method is based on the reaction of oxymetazoline as n-donor with DDQ reagent as π-acceptor in basic aqueous medium of pH 9.79. The maximum absorption is 421 nm. Beer's law was obeyed in the range 0.4-4.0 µg mL-1 with molar absorptivity 2.5 x 104 L mol-1 cm-1. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.0093 and 0.028 µg mL-1 respectively. The stability constant has been determined and the mechanism of the reactions was proposed. The proposed method was applied to determine the oxymetazoline hydrochloride in dosage form as drop, and the results were statistically compared with official BP method.

2015-04

IOSR Journal of Environmental Science, Toxicology and Food Technology (Issue : 4) (Volume : 9)

A simple extraction method based on methanol-soaking coupled with HPLC-UV detection was developed for the simultaneous determination of the potato sprout inhibitor chlorpropham (isopropyl 3-chlorophenyl carbamate) (CIPC) and its degradation product 3-chloroaniline (3-CA) in potato samples using propham (IPC) as an internal standard. The chromatographic conditions selected were 62% methanol at 15 minutes run time and retention times at 11 and 4 minutes for CIPC and 3-CA respectively. The HPLC method was validated reporting good precision and acceptable linearity. The estimated values of LOQ in the organic potato extract based on fresh potato tuber weight were 0.01 and 0.02 mg/kg of CIPC and 3-CA respectively. The initial extraction using overnight methanol-soaking gave recovery values of up to 90% for CIPC following spiking organic potato peel for 1 hour at spiking levels of 0.8 and 8.0 μg/g. However, 3-CA recovery was found to be very low (< 10%) particularly at the lower level of 0.8 μg/g when no 3-CA was detected. To improve the extractability of 3-CA, the extracting solution of methanol was acidified by adding sulphuric acid. Optimising the extraction process showed that using 1 M sulphuric acid prepared in 50% methanol as an extracting solution for 24 hours at 50 ºC improved the extraction recovery of 3-CA up to 85% at a spiking level of 8.0 μg/g and contact time 1 hour. This final extraction method was applied for the determination of the residues of both CIPC and 3-CA in commercial potato samples which had received several applications of CIPC reporting high residue values of 3-CA whereas CIPC residues were lower than maximum residue level (MRL) of 10 mg/kg. Keywords: Potato, Chlorpropham; 3-Chloroaniline; Sprout inhibitor; HPLC

2014-12

Chromatography Research International (Issue : 2014) (Volume : 2014)

Chlorpropham (CIPC) is the main sprout inhibitor used by potato industry.There is concern about the residues of CIPC and its degradation product 3-chloroaniline, 3-CA; hence, analytical methods are required to analyse their residues in potato samples. An HPLC-UVmethod was developed and validated for the separation and quantification of these compounds using propham(IPC) as an internal standard.The chromatographic conditions required to achieve good separation were 60%mobile phase of methanol, 15- minute run time at a flow rate of 1.5 mL/min, and a detection wavelength of 210nm using Phenomenex (ODS-2 250mm× 4.60mm 5 𝜇m Sphereclone) column at an ambient temperature. The method was validated for precision, linearity, the limit of detection (LOD) and the limit of quantification (LOQ), producing high precision through RSD ≤ 0.03%, and acceptable criteria of the coefficient of determination (𝑅 2) of the calibration curves (0.990). LOD values of CIPC and 3-CA were approximately 0.01 𝜇g/mL whereas the LOQ values were approximately 0.04 𝜇g/mL using repeated injection approach. The proposed HPLC method was compared with the standard GC method of the CIPC residues extracted showing good agreement (𝑅 2 = 0.99). Despite using the same extract, the recovery results for the proposed HPLC method were 13% higher than GC analysis.

2014-09

Chromatography Research International (Issue : 2014) (Volume : 2014)

1,4-Dimethylnaphthalene (1,4-DMN) is effective sprout suppressant used in potato stores in many countries in the world. High residue levels of this compound on the potatoes and in other environmental samples are considered for human health and environmental risks. Determination of the residue requires specific analytical methods to be developed and validated. In this study, HPLC-UV was selected for validating a separation method based on reversed phase for the analysis of 1,4-DMN using 2-methylnaphthalene (2-MeN) as internal standard testing three HPLC systems. Under the same chromatographic conditions, all three systems achieved good separation on a Jones column (Hypersil ODS 5 𝜇m, 250mm× 4.6 mm) at ambient temperature isocratically using 70% acetonitrile as mobile phase at a flow rate of 1.5mLmin−1, 20𝜇L injection volume, a run time of 10 min, and a detection wavelength of 228 nm. All three systems showed high precision, good linearity, and low limit of detection (LOD) and quantification (LOQ); particularly, the SpectraSERIES UV100-autosampler system offered lower values of LOD (0.001– 0.004 𝜇gmL−1) and LOQ (0.002–0.013 𝜇gmL−1) for both compounds. This system can be used for the quantitative determination of 1,4-DMN residue in potato and environmental samples.