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Chemical engineering is an engineering branch that deals with the chemical production and manufacture of products that undergo chemical processes. This includes equipment design, creating systems and processes to refine raw material, as well as mixing, compounding, and processing chemicals to create products.

Chemistry and Chemical Engineering

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Abstract

We developed and validated a liquid chromatography–mass spectrometry (LC–MS/MS) method for detecting conivaptan, an arginine vasopressin receptor blocker, in human plasma to facilitate future pharmacokinetic studies. After acetonitrile protein precipitation, analytes were separated on a Grace Alltima HP C18 reverse-phase column (5 μm, 2.1 × 50 mm), and gradient elution was performed using 0.1% formic acid and 5 mM ammonium formate in acetonitrile–water (1:9) and acetonitrile–water (9:1) over a 4-min run time. Positive-mode electrospray ionization and multiple reaction monitoring were applied. The assay was linear over the concentration range of 1–500 ng mL−1, with confirmed accuracy (intra-batch, 0.5–1.1%) and precision (intra-batch relative standard deviation [RSD], ≤5.7%; inter-batch RSD, ≤6.8%). Extraction recovery varied between 94.2–100.5%, and the matrix effect was 94.9–97.0%. To establish the stability, we examined plasma for 17 h at room temperature, 21 h at 2–8 °C, 57 days at −70 °C for three freeze-thaw cycles, and after processing for 52 h in the autosampler. We detected acceptable stability under all examined conditions. Hemolysis, hyperlipidemia, and dilution integrity satisfied the validation criteria. The method developed in this current study will help accurately quantify conivaptan in human plasma and define its clinical pharmacokinetics in the future.

Open access

Abstract

This work developed and validated a new UV-HPLC method for the separation and quantification of vonoprazan fumarate (VNP), amoxicillin (AMX), and clarithromycin (CLM), together in a ternary mixture and in laboratory-prepared tablets. A C18 column and a delightful 70:30 blend of 0.05 M KH2PO4 buffer pH 6 and acetonitrile were used as mobile phase. The flow rate was 1.5 mL min−1, while the wavelength of detection was 254 nm. Linear concentration ranges of (1.0–10.0 μg mL−1) vonoprazan fumarate, (1.0–125.0 μg mL−1) amoxicillin, and (25.0–1,200 μg mL−1) clarithromycin resulted in 0.061, 0.6213, and 7.302 μg mL−1 detection levels and 0.1849, 0.845, and 22.127 μg mL−1 quantification values for VNP, AMX, and CLM, respectively. The greenness of this method was evaluated using the National Environmental Methods Index assessment (NEMI), analytical Eco-scale Assessment (ESA) tool, Green Analytical Procedure Index assessment (GAPI), and Analytical Greenness metric assessment (AGREE), which authenticated the method to be eco-friendly. This method, which was systematically validated and used also to calculate the concentration of the three drugs in their dosage forms, showed high accuracy and precision. Additionally, it produced peaks that were clearly separated and resolved, demonstrating its robustness and specificity.

Open access
Agrokémia és Talajtan
Authors:
Digambar Aggayya Jakkan
,
Pradnya Ghare
,
Nirmal Kumar
, and
Chandrashekhar Sakode

Soil organic carbon (SOC) levels directly affect the production and health of crops. Making use of a database of the usefulness of using the 350–2,500 nm Near Infra Red (NIR) spectroscopy data range on 200 soil samples from the Indian state of Uttar Pradesh was evaluated in this study. The more sophisticated Artificial Neural Network, to choose the spectral components that were used to forecast SOC, Random Forest (RF) and Ensemble Lasso-Ridge Regression (ELRR) were utilized. In the preprocessing, the inversion derivative, logarithmic(log) derivative, and logarithmic base to 10(log10x) derivatives were employed to duplicate the spectrum wavelength. The main characteristic of spectrum wavelength for SOC were found to be within the range of 350 and 450 nm, per the results. The best accurate estimation of SOC content was obtained by combining the suggested DSANN or Dropout Sequential ANN technique with the Log10x pre-processed data. The R-squared (R2), RMSE, and RPIQ (Ratio of Performance in Inter Quartile Distance) values for the testing dataset were 0.83, 0.08, and 4.32, respectively.

Restricted access

Abstract

The preservation of water resources is seriously threatened by the rise of pharmaceutical contamination. Ribavirin, a widely used antiviral drug, is among the pharmaceutical residues in wastewater. In this study, the adsorption capacity of activated carbon produced from tobacco stems, a by-product of the cigarette industry, was investigated. The produced activated carbon was characterised by BET, SEM-EDX and FTIR analyses. In the next step, removal of ribavirin from aqueous solutions using activated carbon was investigated. In the next step, the removal of ribavirin from aqueous solutions was tested with this activated carbon. Various factors such as initial ribavirin concentration (10–50 μg mL−1), solution pH (4–10), adsorbent amount (5–30 mg per 50 mL solution), contact time (0–150 min) and temperature (300–328 K) were investigated to determine the optimum adsorption conditions. Adsorption kinetics were investigated with first and second order pseudo models, and the equilibrium state was analyzed with Langmuir and Freundlich isotherm models. Thermodynamic parameters were calculated at different temperatures (300, 308, 318 and 328 K). The results show that a maximum removal efficiency of 91.83% was achieved at an initial concentration of 30 μg mL−1, adsorbent dose of 20 mg, contact time of 90 min and pH 7.00. The adsorption process was best described by the pseudo-second order kinetic model (R 2: 0.9987) and Langmuir isotherm model (R 2: 0.9971). Thermodynamic analysis shows that the process is spontaneous (ΔG < 0), exothermic (ΔH < 0) and causes a decrease in disorder in the system (ΔS < 0). This study reveals that tobacco stems can offer an environmentally friendly and economic treatment alternative.

Open access
Acta Chromatographica
Authors:
Nguyen Thi Thanh Ngoc
,
Nguyen Thi Khanh Huyen
,
Nguyen Mai Anh
,
Sadao Matsuzawa
,
Nguyen Thanh Duy
,
Dang Phan Anh
,
Ngo Bang Chau
,
Nguyen Tien Dat
,
Hoang Le Tuan Anh
,
Nguyen Quang Trung
, and
Truong Ngoc Minh

Abstract

Aflatoxins (AFs) and deoxynivalenol (DON), common mycotoxins in cereals, pose contamination risks in beer production, often persisting from raw barley into final products. This study investigates the transfer and decomposition of AFs and DON during the barley steeping stage of malting. Barley spiked with AFs and DON was steeped, and mycotoxin concentrations were analyzed in both the barley residue and the resulting wastewater. Results indicated that AF and DON transfer into wastewater was influenced by water solubility, though concentrations remained below solubility limits. AFs and DON residues were also detected in the steeped barley. Decomposition studies showed that while AFs were partially degraded by UV light, DON required photocatalysis for effective degradation. However, matrix components in wastewater decreased the efficiency of DON decomposition, suggesting that preliminary removal of organic components from wastewater could enhance photocatalytic detoxification. These findings provide insight into mycotoxin management strategies for brewing wastewater, emphasizing the need for targeted pretreatment to improve degradation efficiency.

Open access

Abstract

The aim of the current investigation to estimate the amount of theobromine (THEOB), theophylline (THEOP) and caffeine (CAF) concurrently using ultra performance liquid chromatography with photo diode array detector (UPLC-PDA) in ultrasound assisted extract of commercially available food products. The commercially available products are categorized in three different groups including teas, coffees and chocolates. The UPLC approach is rapid, precise, highly sensitive and cost effective for the concurrent assessment of THEOB, THEOP and CAF in ultrasound assisted extract of commercially available food products. The mobile phase comprises a mixture of water and ACN (90:10, v/v) for the concurrent assessment of THEOB, THEOP and CAF in ultrasound assisted extract of commercially available food products. The current approach operated on a linear scale range of 6.66–33.3 ng mL−1, 3.33–33.3 ng mL−1 and 3.33 – 33.3 ng mL−1, respectively, for THEOB, THEOP and CAF at 272.5 nm wavelength. The LOD for THEOB, THEOP and CAF were assessed to be 1.10 ± 0.001, 0.75 ± 0.000 and 0.48 ± 0.002 ng mL−1, respectively by applying the present approach. The LOQ for THEOB, THEOP and CAF were assessed to be 3.35 ± 0.009, 2.29 ± 0.001 and 1.47 ± 0.001 ng mL−1, respectively by applying the present approach. These findings confirmed that the current UPLC approach is highly sensitive, accurate, precise and robust for the concurrent assessment of THEOB, THEOP and CAF in ultrasound assisted extract of commercially available food products. Antioxidant activity of different teas, coffees, chocolates as well as standard THEOB, THEO and CAF were determined by DPPH method.

Open access

Abstract

Osimertinib (Tagrisso, AstraZeneca Pharmaceuticals) is the inaugural third-generation irreversible EGFR-TKI that specifically targets both the EGFR T790M resistant mutation and EGFR-TKI-sensitizing mutations. On September 25, 2024, the Food and Drug Administration authorized osimertinib (OSM) for adult patients with locally advanced, unresectable (stage III) non-small cell lung cancer (NSCLC). The target of this work was to establish a fast, accurate, environmentally friendly, and highly sensitive UPLC-MS/MS methodology for detecting OSM levels in human liver microsomes (HLMs). The separation of OSM and zanubrutinib (ZNB) was accomplished utilizing a C8 column and an isocratic mobile phase. The linearity of the OSM calibration curve spanned from 1 to 3,000 ng mL−1. The AGREE score of 0.76 validates the efficacy of the current approach. The brief in vitro half-life (23.72 min) and moderate intrinsic clearance (34.18 mL min−1 kg−1) of OSM indicate that it resembles drugs with a moderate extraction ratio. The present LC-MS/MS technique is regarded as the primary analytical methodology for quantifying OSM in HLM matrices. The characterization of OSM metabolic stability and in silico ADME features are crucial for progressing the discovery of novel drugs with improved metabolic stability.

Open access

Abstract

Apples are among the most common fruits, produced on the territory of North Macedonia. Before they reach the market, it is essential to be tested for pesticide residues, which are used for protection against pests for this culture, and in order to ensure the customer safety. For this reason, a novel and simple method for simultaneous determination of captan, folpet, difenoconazole and chlorpyrifos in apple samples has been developed and validated. Acetone is used for extraction of the pesticide residues, followed by liquid-liquid (LLE) and solid–phase extraction (SPE). Separation and quantification of analytes is achieved on reversed-phase high performance liquid chromatography (RP-HPLC) with UV diode array detector (UV-DAD). The best results are obtained using analytical column LiChrospher 60 RP-select B (250 mm × 4 mm, 5 µm), with isocratic elution and acetonitrile/0.1 % acetic acid in water (70:30, V/V) as a mobile phase. The flow rate is 1 mL min−1, and UV detection is performed at 220 and 230 nm. The linearity of the method is tested in the range of 1.50–3.60 mg kg−1 for captan and folpet, and 0.35 – 0.60 mg kg−1 for difenoconazole and chlorpyrifos. The obtained values for recovery and RSD ranged from 94.94 to 114.63 %, and 0.09–9.25 %, respectively. The validated method is successfully applied to apple samples for the determination of the investigated pesticide residues.

Open access
Acta Chromatographica
Authors:
Thanh Duy Nguyen
,
Thuy Ngan Ha Nguyen
,
Tuan Kiet Ly
,
Thanh Tho Le
,
Ngoc Minh Truong
,
Tien Dat Nguyen
, and
Quoc Hung Nguyen

Abstract

Aflatoxins, potent carcinogenic mycotoxins produced by Aspergillus species, persist in various foods, posing significant health risks upon consumption. This study assesses dietary aflatoxin B1 (AFB1) exposure in Vietnam using Margin of Exposure (MOE) and Hazard Index (HI) to evaluate risk levels in peanuts, chili powder, corn, and raisins. AFB1 levels were quantified by UPLC-FLD. AFB1 was detected in 71.5% of chili powder, 29.3% of peanuts, and 26.0% of corn samples, with no detectable levels in raisins. Peanuts and corn kernels were classified as high-risk, with MOE values below 10,000 (peanuts: 25.8–56.6; corn: 42.3–92.6) and HI values exceeding 1, potentially contributing to 20.4–44.7 and 12.5–27.3 liver cancer cases per 100,000 adults, respectively. In contrast, chili powder had MOE values between 3,208 and 7,021 and HI below 1, indicating a low public health risk. Raisins were deemed safe with MOE over 200,000 and HI at 0.01. Results also indicated higher cancer risk for women and lean individuals consuming the same AFB1 levels. These findings underscore the need for focused risk management strategies to mitigate AFB1 exposure and protect public health in Vietnam.

Open access
Acta Chromatographica
Authors:
Muhammad Sajid Nawaz
,
Muhammad Hasnat
,
Muhammad Zaman
,
Majid Alhomrani
,
Abdulhakeem S. Alamri
,
Waqar Siddique
,
Muhammad Amer
,
Qurat-ul-ain shoaib
, and
Kanwal Shahzadi

Abstract

In the field of pharmaceutical analysis, high-performance liquid chromatography (HPLC) is considered to be the key technique, which is one of the most efficient, quick, and easy methods for the simultaneous determination of two are more drugs. The purpose of the current study is to develop and validate the reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of Paracetamol and Fexofenadine HCl. This approach was validated by the standards and The International Conference on Harmonization (ICH), and United States Pharmacopeia (USP) were followed in the development and validation of the method. The chromatographic conditions including a mobile phase comprised of a 35:65 buffer mix and acetonitrile with a 1.0 mL min−1 flow rate were used. A thorough investigation was performed, including linearity and range, specificity, robustness, accuracy, precision, solution stability, and system suitability. The outcomes of the studies have shown that, both Active Pharmaceutical ingredients i.e., Paracetamol and Fexofenadine HCl were separated in about 7.5 min. The variation coefficient for Paracetamol and fexofenadine HCl varied between 0.9992 R 2 and 0.9983 R 2, respectively. The devised method was proved accurate, as API recoveries in both cases of Paracetamol and Fexofenadine ranged from (99.79%, 100.72%, and 98.64%) to (99.96%, 100.64%, and 99.00%). The method's accuracy was further demonstrated by the solution stability which was 99.84% for Paracetamol, and 100.53% for Fexofenadine HCl. The suggested method for simultaneously measuring Paracetamol and Fexofenadine HCl was established, validated, and there was no evidence of any excipient interaction was observed.

Open access