Limit Of Quantification Values Research Articles

Hydroxymethylfurfural Content and Sugar Profile of Honey Available in Bangladesh Using Validated HPLC-PDA and HPLC-RID

Background: Honey has a lot of reputation because of its supposed medicinal properties. In this study, Hydroxymethylfurfural (HMF), sugars, and Fructose/Glucose ratio of honey in Bangladesh were assessed for adulteration and authenticity evaluation.
 Methods: Seventy honey samples collected from different districts of Bangladesh were analyzed by High Performance Liquid Chromatography (HPLC) for HMF content and sugar profile. The samples were prepared by using Carrez I and Carrez II prior to injecting into HPLC. The samples were then filtered through syringe filter and taken in 1.5 ml vial for injecting into the HPLC system.
 Results: HMF values were ranging from 1.41 mg/kg to 2,063.90 mg/kg. The Limit of Detection (LOD) and Limit of Quantification (LOQ) was found 0.10 mg/kg and 0.33 mg/kg with R2=0.9994. The average values of fructose, glucose, and sucrose were in the range of 14.75-52.44%, 8.19-42.63%, and 0.10-21.12%, respectively. From validation parameters, LOD values for fructose, glucose, and sucrose were 0.003, 0.008, and 0.004%, respectively; and LOQ values were 0.01, 0.028, and 0.015%, respectively with an excellent linearity with R2 for fructose=1.0, glucose=0.9999, and sucrose=1.0.
 Conclusion: Some samples had higher HMF content which may be due to the storage time was increased and improper processing with high temperature or adulteration by High Fructose Corn Syrup (HFCS), sugar cane syrup, rice syrups or rice molasses. The sugar profiles showed that the most of honey samples were nectar honeys.

Development and validation of an LC-MS/MS method for D- and L-2-hydroxyglutaric acid measurement in cerebrospinal fluid, urineand plasma: application to glioma.

Aim: IDH mutations have been identified as frequent molecular lesions in several tumor types, particularly in gliomas. As a putative marker of IDH mutations, elevated D-2-HG has been reported in glioma, acute myeloid leukemia and intrahepatic cholangiocarcinoma. Excessive production of L-2-HG has also been described in renal cell carcinoma and 2-hydroxyaciduria. Materials & methods: The authors present a fully optimized stable isotope dilution multiple reaction monitoring method for quantification of D-/L-2-HG using LC-MS/MS. This is the first method validation study performed on cerebrospinal fluid, plasmaand urine demonstrating clinical applicability with samples from glioma patients. Results & conclusion: This method validation study showed high accuracy and precision with low limit of detection and limit of quantification values. The authors believe that the presented approach is highly applicable for basic and clinical research on related pathologies.

Analysis of two intestinal bacterial metabolites (trimethylamine N-oxide and phenylacetylglutamine) in human serum samples of patients with T2DM and AMI using a liquid chromatography tandem mass spectrometry method

BackgroundTrimethylamine N-oxide (TMAO) and phenylacetylglutamine (PAGln) are associated with acute myocardial infarction (AMI) and type 2 diabetes mellitus (T2DM). This study developed and validated a simple method firstly for simultaneously quantifying serum TMAO and PAGln using liquid chromatography-tandem mass spectrometry (LC–MS/MS). MethodsSerum samples from patients with T2DM, AMI, and healthy subjects were analyzed using a new LC–MS/MS method to evaluate TMAO and PAGln levels. Statistical analyses were performed to evaluate TMAO and PAGln distributions among different groups. ResultsRetention and separation of the two metabolites were achieved within 5 min. For both analytes, the assay was linear in a 0.02–10 µg/mL range, with >0.99 average linear correlation coefficients, and quantification limit values of approximately 0.010 µg/mL. The average recoveries of TMAO and PAGln were 96.3 % and 96.4 %, respectively. The intra-run and total coefficient variations were 3.5–4.8 % and 3.9–5.7 % respectively for TMAO; and 4.0–5.1 % and 4.6–6.3 % respectively for PAGln. TMAO and PAGln showed a moderate correlation (P < 0.001) and their levels in patients with T2DM were significantly higher than those in healthy individuals (P < 0.001). TMAO levels were higher in patients with T2DM than in patients with AMI (P < 0.01). Patients with AMI had higher PAGln levels than healthy individuals (P < 0.05). After adjusting for sex and age, the top tertile of PAGln was positively correlated with T2DM and AMI while that of TMAO was positively correlated with T2DM. ConclusionsOverall, a robust isotope dilution LC–MS/MS method was established, which may be beneficial for assessing the association between two metabolites with AMI and T2DM.

Appraisal and validation of a method used for detecting heavy metals in poultry feed in Bangladesh.

Low concentrations of heavy metals are toxic and pose a serious threat to human health and the environment. Therefore, regular assessments of the toxic metal content in poultry feed are crucial for evaluating feed quality and customer safety. It is difficult to determine the heavy metals in the poultry feed at the trace amount. Therefore, this study aimed to validate this method through the detection of three heavy metals, chromium (Cr), cadmium (Cd), and lead (Pb), in poultry feed samples. Graphite furnace atomic absorption spectrometry (GF-AAS) method was used to analyze the heavy metals in poultry feed according to the guidelines given by the Council Directive 333/2007/EC, Commission Decision 657/2002/EC. In this study, various parameters such as linearity check, limit of detection (LOD), limit of quantification (LOQ), recovery percentage, precision checks, repeatability, reproducibility, and uncertainty measurement were considered to validate and assess the method following international guidelines. Heavy metals, such as Pb, Cr, and Cd, were analyzed from the feed samples in the laboratory using the GF-AAS method (Model: AA-7000 Shimadzu, Japan) with high purity argon as the inert gas, and the absorbance was read at wavelengths of 283.0, 357.9, and 228.8 nm, respectively. The coefficient of variation (CV%) for system suitability and precision data was <10% for all the metals (Pb, Cr, and Cd) detected in this study. The overall CV% of repeatability and reproducibility ranged from 8.70% to 8.76% and 8.65% to 9.96%, respectively. The linearity of the calibration curves was excellent (r2 > 0.999) at various concentration levels for the three different metals. The recovery (%) was found to be 94.53, 93.97, and 101.63% for Pb, Cr, and Cd, respectively. The LOD values in feed were 0.065, 0.01, and 0.11 mg/kg, and the LOQ values were 0.22, 0.03, and 0.38 mg/kg for Cr, Cd, and Pb, respectively. The values recorded for the measurement uncertainty (%) were 11.48, 4.43, and 12.42% for Cr, Cd, and Pb, respectively. The results show that these study criteria or parameters have met the validated or acceptable range. Therefore, it is a reliable technique that can be used undoubtedly for the routine analysis of heavy metals in poultry feed samples across the globe.

Novel 5-(2-phenylbenzo[b]thiophen-3-yl)furan-2-carbaldehyde based ovarian cancer carbohydrate antigen 125 electrochemical sensor

Herein, an electrochemical sensor based 5-(2-phenylbenzo[b]thiophen-3-yl)furan-2-carbaldehyde (PTFC) was developed for the detection of cancer antigen 125 (CA125). Measurements were obtained via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV), and square wave voltammetry (SWV) techniques to investigate features of the electrochemical sensor such as concentration effect of CA125, incubation time, scan rate, limit of quantification (LOQ), limit of detection (LOD), and interference effect of structures found in serum. The sensor was found to have a fairly wide linear range as 0.01–100 ng mL−1 and 100–1000 ng mL−1. LOQ and LOD values were determined as 0.024015 ng mL−1 and 0.008005 ng mL−1 (S/N = 3), respectively. These results showed that the PTFC-based electrode could be a promising electrode for the detection of CA125.

VALIDASI METODE ANALISIS SENYAWA ETIL p-METOKSISINAMAT DALAM PLASMA DARAH TIKUS PUTIH JANTAN GALUR WISTAR MENGGUNAKAN KROMATOGRAFI CAIR KINERJA TINGGI

Ethyl p-methoxycinnamate (EPMC) isolated from the rhizome of kencur (Kaempferia galanga L) is being developed at STFI. Validation of EPMC analysis in blood plasma using High-Performance Liquid Chromatography (HPLC) needs to be conducted to perform in vivo EPMC analysis. This study aims to validate the EPMC analysis method in blood plasma using HPLC. The HPLC column used is column C18, with methanol : phosphoric acid 70:30 and 80:20 mobile phases, a flow rate of 1.0 mL/min, and a maximum wavelength of 310 nm. The blood plasma used was the blood plasma of white male rats of the Wistar strain. EPMC was added to blood plasma and analyzed using HPLC. Parameter validation used is system suitability test, linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). The results showed that the optimum mobile phase for analyzing EPMS in plasma was methanol : phosphoric acid with a ratio of 70:30. Based on the validation, the linear regression was 0.998. In the accuracy test, the average value range for the percent recovery is 98% - 102%. In the precision test, the average value of the RSD percentage was 4.10% - 68.83%. The LOD value is 2.747 g/mL, and the LOQ value is 9.158 g/mL. Based on this research, it can be concluded that EPMC in blood plasma can be analyzed using KKKT with column C18 and mobile phase methanol : phosphoric acid 70:30.

Quantitative Analysis of Fat-Soluble Vitamins in Feed Additives Using an In-House Developed and Validated HPLC Method

Quantification of vitamins in complex matrices such as feed additives is a time-consuming analytical procedure. In this study, a simple and precise in-house High Performance Liquid Chromatography (HPLC) method was developed and validated for the simultaneous detection and quantification of four fat-soluble vitamins such as vitamin A, D3 , E, and K3 in feed additives. The HPLC method was developed and validated using reversed-phase column chromatography. The chromatographic separation of the vitamins was carried out at 25° C temperature on a reverse-phase C18 column using a binary gradient pump mode. Mobile phase constituents were solvent (a): deionized water and (b) methanol. Detection was performed with HPLC ultraviolet/visible detection set at 325, 265, 230, and 254 nm wavelength for vitamin A, D3 , E, and K3 respectively. The flow rate was 1.0mL/min and the total run time was 20min. The method was validated according to the guidelines of the International Conference on Harmonization (ICH) and Food and Drug Administration (FDA), USA, and acceptance criteria for system suitability, specificity, linearity, accuracy, and precision were met in all the cases. The Relative Standard Deviation (RSD) for system suitability and precision was &lt;2% for all the studied vitamins. The linearity of the calibration curves was excellent (R2 &gt;0.999) at concentrations of 2.5, 5.0, 7.5, 10.0, 15.0, and 20.0 µg/mL for all vitamins, and the range of linearity of this method was 0.0-50.0 μg/mL with R2 value greater than 0.999. The limits of detection values were 0.0022, 0.0012, 0.0022, and 0.0020 µg/ mL for vitamin A, D3 , E, and K3 , respectively, and the limits of quantification values were 0.0066, 0.0038, 0.0066, and 0.0061 µg/mL for vitamin- A, D3 , E, and K3 respectively. The recovery percentages ranged from 85% to 103%, and the robustness of the method is also high with excellent reproducibility. The overall parameters of the proposed method met the validation criteria and this method could be a precise and highly desirable analytical procedure for accurate quantification of four fat-soluble vitamins such as A, D3 , E, and K3 in feed additives using a single chromatographic run.

APPLICATION OF TWO ADVANCED DERIVATIVE SPECTROPHOTOMETRIC METHODS FOR SIMULTANEOUS ESTIMATION OF SALBUTAMOL SULPHATE, AMBROXOL HYDROCHLORIDE AND THEOPHYLLINE IN PURE AND COMMERCIAL FORMULATIONS

Objective: Two advanced spectrophotometric methods have been proposed for the simultaneous determination of Salbutamol sulphate, Ambroxol hydrochloride and Theophylline in pure and pharmaceutical formulations. The proposed methods exclude the hectic steps of time-consuming sample preparations or purification or separation steps. There is no any spectrophotometric method has been avail for simultaneous estimation of the ternary mixture containing Salbutamol sulphate, Ambroxol hydrochloride and Theophylline.&#x0D; Methods: The methods are derivative ratio spectra zero-crossing method and double divisor ratio spectra derivative method respectively. Both the methods are found to be rapid, accurate, precise, reliable and economical as well. The developed methods show best results in terms of linearity, accuracy, precision, limit of detection and limit of quantification for standard laboratory mixtures of pure drugs and marketed formulations.&#x0D; Results: The range for Salbutamol sulphate, Ambroxol hydrochloride and Theophyllineare found to be 1-35 µg ml-1, 5-35 µg ml-1and 6-60 µg ml-1 respectively. For the derivative ratio spectra zero-crossing method, the values of the limit of detection are found to be 0.3161 µg ml-1, 0.2212 µg ml-1 and 0.2910 µg ml-1 and the values limit of quantification are found to be 0.9571 µg ml-1, 0.7412 µg ml-1 and 0.9671 µg ml-1 for Salbutamol sulphate, Ambroxol hydrochloride and Theophylline respectively. For double divisor ratio spectra derivative method, limit of detection values is found to be 0.3251 µg ml-1, 0.2591 µg ml-1 and 0.2640 µg ml-1 and the limit of quantification values are found to be 0.9870 µg ml-1, 0.8650 µg ml-1 and 0.8812 µg ml-1 for Salbutamol sulphate, Ambroxol hydrochloride and Theophylline respectively.&#x0D; Conclusion: The common excipients and additives did not interfere in the determinations of any of the drugs while being analysed for commercial formulations. These two spectrophotometric methods, which determine SS, AH, and THE simultaneously, are simple, specific, accurate, precise, rapidly, and economically, indicating that they can be used routinely in pharmaceutical analysis. As a result, derivative spectrophotometry may be used effectively for the simultaneous determination of SS, AH and THE in the combined dosage forms without any prior separation of individual drugs.

Separate Analysis of Loquat Fruit Pulp, Peel, and Pits to Calculate Pesticide Residue Levels in the Whole Commodity

To evaluate the effects of handling "not detectable" residues (ND: <0.01 mg/kg) in the pulp and detectable residues in the pits on the calculation of pesticide residue in the whole fruit, residue levels in the pulp, peel, and pits of loquat fruits were separately analyzed. Following conventional Japanese agricultural practices, 16 pesticides were sprayed at the maximum application rates in three test fields. All target pesticides were detected at quantifiable levels in the peel (n=144). In contrast, the percentages of detected pesticides in the pulp and pits were 42% (n=61) and 36% (n=52), respectively. Most pesticide residues were present in the peel. For comparison, the pesticide residue levels in the whole fruits were determined based on three indices: the highest estimate (H), calculated using the measured residue levels in the pits and by replacing the ND residues in the pulp as the limit of quantification (LOQ) values; conventional estimate (C), calculated by neglecting all residues in the pits (0 mg/kg) and replacing the ND residues in the pulp as LOQ values; and the lowest estimate (L), calculated by neglecting all residues in the pits and the ND residues in the pulp (0 mg/kg). The L/C and H/C ratios ranged from 74% (L/C) to 106% (H/C). In seven of eighty-three cases with less than 90% difference, residue levels in the whole loquat fruits were low (≤0.06 mg/kg), with the actual range being equal to or below the minimum unit of 0.01. In comparison of three field datasets, the range of residue levels was estimated to be 2.77 mg/kg. Based on the results of separate analysis, handling of ND residues in the pulp and detectable residues in the pits did not significantly affect the calculated pesticide residue levels in the whole loquat fruits.

Validated Method for the Determination of Five Membered Heterocyclic Polar Compound Imidazole in Drug Substances Using Capillary Electrophoresis and UV Detection

A simple and sensitive method based on capillary electrophoresis with UV detection was developed, optimized, and validated for the determination of five membered heterocyclic polar compound, imidazole in pharmaceutical drug substances. Separation was achieved on bare fused silica capillary using a simple running buffer, potassium dihydrogen phosphate at pH 4.0. Capillary temperature set at 25°C. The applied voltage was 25 kV across the capillary and the samples were injected by hydrodynamically at a pressure of 50 mbar for 5 s. Analyte was monitored at 210 nm. The achieved limit of detection value was 0.005%w/w, limit of quantification value was 0.014%w/w, and the average accuracy value was 98.4% for imidazole. The aim of present study is to develop a specific and sensitive method for the determination of imidazole to overcome the void volume and sample matrix interferences.

Lab-In-Syringe automation of deep eutectic solvent-based direct immersion single drop microextraction coupled online to high-performance liquid chromatography for the determination of fluoroquinolones

Lab-In-Syringe direct immersion single drop microextraction is proposed as an automated sample pretreatment methodology and coupled online to HPLC with fluorescence detection for the determination of fluoroquinolones in environmental waters. For the first time, a drop of a natural deep eutectic solvent (NADES), synthesized from hexanoic acid and thymol, has been used as an extractant in automated single-drop microextraction. The extraction procedure was carried out within the 5 mL void of an automatic syringe pump. A 9-position head valve served the aspiration of all required solutions, air, waste disposal, and hyphenation with the HPLC instrument. Sample mixing during extraction was done by a magnetic stirring bar placed inside the syringe. Only 60 μL of NADES were required omitting toxic classical solvents and improving the greenness of the proposed methodology. By direct injection, linear working ranges between 0.1 and 5 μg L−1 were achieved for all fluoroquinolones. The limit of quantification values and enrichment factors ranged from 20 ng L−1 to 30 ng L−1 and 35 to 45, respectively. Accuracies obtained from the analysis of spiked surface water and wastewater treatment plant effluent analysis at two concentration levels (0.5 and 4 μg L−1) ranged from 84.6% to 119.7%, with RSD values typically <3%.

Rapid and simultaneous determination of glyphosate, glufosinate, and their metabolites in soil by high performance liquid chromatography-tandem mass spectrometry

建立了快速同时测定土壤中草甘膦(GLY)、草铵膦(GLUF)及其代谢物的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。分别对前处理和色谱-质谱条件进行优化,样品采用0.5 mol/L氨水作为溶剂振荡提取,离心,上清液过滤膜后,直接采用HPLC-MS/MS测定,电喷雾离子源(ESI-),多反应监测(MRM)模式下检测,外标法定量。结果表明,采用Dikma Polyamino HILIC色谱柱(150 mm×2.0 mm, 5 μm)进行分离,目标化合物峰形良好,响应值高。GLY及其代谢物氨甲基膦酸(AMPA)在5.0~500 μg/L范围内线性关系良好;GLUF及其代谢物N-乙酰基-草铵膦(NAG)、3-(甲基膦基)丙酸(MPP)在2.0~500 μg/L范围内线性关系良好;5种化合物的相关系数(r2)均大于0.998,可以满足定量分析的要求。GLY、GLUF及其代谢物的方法检出限(LOD)在2.0~4.0 μg/kg之间,方法定量限(LOQ)在6.7~13.3 μg/kg之间。在空白土壤样品中添加0.02、0.05、0.2 mg/kg 3个水平的5种化合物混合标准溶液考察回收率,结果表明,低有机质含量土壤中5种化合物的平均加标回收率在74.2%~101%之间,相对标准偏差(RSD)在0.93%~6.8%之间;高有机质含量土壤中5种化合物的平均加标回收率在90.8%~116%之间,RSD在0.40%~7.1%之间。采用建立的方法对实际土壤样品进行测定,AMPA、GLY、MPP、GLUF、NAG的检出率分别为45%、25%、10%、5%和5%,最大残留量分别为147、35.2、154、21.6和11.0 μg/kg,说明土壤中GLY、GLUF及其代谢物残留需要引起一定的关注。该方法简化了前处理步骤,具有简单、快速、绿色环保、成本低、准确度和灵敏度高、重现性好等优点,适用于大批量不同有机质含量土壤样品的检测,为研究其在土壤中的残留状况和环境行为提供了可靠的技术支持。

Synthesis and characterization of 4-(2-(4-methoxyphenyl)benzo[b]thiophen-3-yl)benzaldehyde for carbohydrate antigen 125 electrochemical detection and molecular docking modeling

4-(2-(4-methoxyphenyl)benzo[b]thiophen-3-yl)benzaldehyde (MPBB)-based chemical antibody is developed to detect CA125 (MUC-16) level more effectively via electrochemical methods. Novel MPBB is synthesized by using Pd-catalyst coupling reactions and electrophilic cyclization reactions. New benzothiophene structure is dispersed in Nafion solution and CA125 antigen was incubated on this electrode. Optimum conditions are found as 3 μL MPBB loading, 30 ng/mL CA125 antigen concentration, and 90 min incubation time. Two distinct linear ranges of the electrode prepared at optimum conditions are determined by DPV as 5–50 ng/ml and 100–500 ng/ml. Limit of detection and limit of quantification values have been obtained as 0.03385 ng/mL and 0.10155 ng/mL, respectively. Interference and artificial serum results reveal that this electrode is a promising electrode for CA125 antigen determination for ovarian cancer. Binding energy is investigated by employing a molecular docking modeling study between CA125 antigen and MPBB. Electrochemical results and molecular docking results revealed that the MPBB is a promising alternative to marketed CA125 immunoassays.

Ion-Imprinted Polymer-on-a-Sensor for Copper Detection.

The accumulation of metal ions in the body is caused by human activities and industrial uses. Among these metal ions, copper is the third most abundant ion found in the human body and is indispensable for health because it works as a catalyst in the iron absorption processes. However, high doses of copper ions have been reported to generate various diseases. Different types of sensors are used to detect metal ions for several applications. To design selective and specific recognition sites on the sensor surfaces, molecular imprinting is one of the most used alteration methods to detect targets by mimicking natural recognition molecules. In this study, an ion-imprinted polymer-integrated plasmonic sensor was prepared to selectively detect copper (Cu(II)) ions in real-time. Following different characterization experiments, the Cu(II)-imprinted plasmonic sensor was employed for kinetic, selectivity, and reusability studies. According to the results, it was observed that this sensor can measure with 96% accuracy in the Cu(II) concentration range of 0.04–5 μM in buffer solution. The limit of detection and limit of quantification values were computed as 0.027 µM and 0.089 µM. The results also showed that this plasmonic sensor works successfully not only in a buffer solution but also in complex media such as plasma and urine.

Development of an Automated Chemiluminescent Enzyme Immunoassay for Measuring Thrombopoietin in Human Plasma.

Plasma thrombopoietin (TPO) measurements help distinguish between different types of thrombocytopenia but are not feasible in routine clinical practice. We developed a fully automated quantitative chemiluminescent enzyme immunoassay (CLEIA) for measuring TPO (TPO-CLEIA), which is a one-step sandwich-type assay. This assay utilizes a mouse monoclonal capture antibody, which has the neutralizing epitope of the interaction between TPO and the TPO receptor, and a newly generated rabbit monoclonal detector antibody. In analytical performance studies, this assay showed good linearity over the measuring range and high sensitivity. The limit of quantification (LoQ) of this assay was 3.4 pg/mL; low TPO concentration values of almost all healthy individuals exceeded the LoQ value. In clinical validation studies, TPO levels obtained from patients with aplastic anemia (AA) significantly increased, whereas those of patients with immune thrombocytopenia (ITP) were normal or slightly increased. The cutoff value for TPO-CLEIA corresponding to the previously reported values was useful for distinguishing between ITP and AA. These results suggest that TPO-CLEIA can quantify human plasma TPO levels with high accuracy and sensitivity and has the potential to facilitate routine clinical measurement of TPO in patients with various types of thrombocytopenia.

Validation of a Quantification Method for Curcumin Derivatives and Their Hepatoprotective Effects on Nonalcoholic Fatty Liver Disease.

Curcumin (CM), demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) are major curcumin derivatives found in the rhizome of turmeric (Curcuma longa L.), and have yielded impressive properties to halt various diseases. In the present study, we carried out a method validation for curcumin derivatives and analyzed the contents simultaneously using HPLC with UV detection. For validation, HPLC was used to estimate linearity, range, specificity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Results showed a high linearity of the calibration curve, with a coefficient of correlation (R2) for CM, DMC, and BDMC of 0.9999, 0.9999, and 0.9997, respectively. The LOD values for CM, DMC, and BDMC were 1.16, 1.03, and 2.53 ng/μL and LOQ values were 3.50, 3.11, and 7.67 ng/μL, respectively. Moreover, to evaluate the ability of curcumin derivatives to reduce liver lipogenesis and compare curcumin derivatives’ therapeutic effects, a HepG2 cell model was established to analyze their hepatoprotective properties. Regarding the in vivo study, we investigated the effect of DMC, CM, and BDMC on nonalcoholic fatty liver disease (NAFLD) caused by a methionine choline deficient (MCD)-diet in the C57BL/6J mice model. From the in vitro and in vivo results, curcumin derivatives alleviated MCD-diet-induced lipid accumulation as well as high triglyceride (TG) and total cholesterol (TC) levels, and the protein and gene expression of the transcription factors related to liver adipogenesis were suppressed. Furthermore, in MCD-diet mice, curcumin derivatives suppressed the upregulation of toll-like receptors (TLRs) and the production of pro-inflammatory cytokines. In conclusion, our findings indicated that all of the three curcuminoids exerted a hepatoprotective effect in the HepG2 cell model and the MCD-diet-induced NAFLD model, suggesting a potential for curcuminoids derived from turmeric as novel therapeutic agents for NAFLD.

Validation of LC-MS/MS method for simultaneous determination of chlorpyrifos, deltamethrin, imidacloprid and some of their metabolites in maize silage

In this study, a validation of a multi-residue analysis method was performed for the simultaneous analysis of chlorpyrifos (CHL), deltamethrin (DEL) and Imidacloprid (IMI) residues and some of their metabolites in maize silage, by LC MS/MS. Extraction was conducted with acetonitrile acidified with 1% acetic acid. To avoid the matrix effect, a matrix matched calibration was used. The method was validated according to the SANTE/12682/2019 Guidelines. Selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), trueness (recovery %) and precision (intra-day and inter-day) parameters were evaluated in line with the SANTE document. The linearities of all compounds were quite confident (R2≥ 0.98) and no interference was observed. The LOD and LOQ values were between 2.76 µg kg−1 to 53.61 µg kg−1 and 9.19 µg kg−1 to 178.71 µg kg−1, respectively. The recovery, repeatability RDSr and reproducibility RDSR values of compounds were calculated between 93.7–109.2%, 1–15%, and 1–13%, respectively. Consequently, results obtained with the evaluation of all parameters were found to be compatible with the SANTE validation criteria, so the method was reliable, effective and easy to use for the detection of insecticides and metabolites in maize silage with LC MS/MS.

An Ultra-Sensitive Molecularly Imprinted Poly(Aniline) Based Electrochemical Sensor for the Determination of Bisphenol A in Synthetic Human Serum Specimen and Plastic Bottled Water Samples

We explain the development of an ultra-sensitive molecularly imprinted polymer-based electrochemical sensor for rapid and selective determination of bisphenol A (BPA) in human serum and water samples. Electropolymerization of functional monomer aniline was performed in the presence of BPA by cyclic voltammetry (CV) to prepare a molecularly imprinted poly(aniline) based GCE sensor (MIP(ANI)/GCE). The developed MIP surface was characterized using Fourier-transform infrared spectroscopy, Raman spectrometry, scanning electron microscopy, contact angle measurements, CV, and electrochemical impedance spectroscopy. The MIP(ANI)/GCE sensor showed a highly sensitive performance with a linear range of 1.0 and 8.0 × 10−15 M. The limit of detection (LOD) and limit of quantification (LOQ) values were 0.193 and 0.643 fM, respectively. The applicability of the MIP(ANI)/GCE was assessed by applying it to human serum and plastic bottled water samples. The LOD and LOQ values were calculated as 0.257 and 0.856 fM for the serum sample. Imprinting factor and interference studies were also carried out using similarly structured compounds and the most common interfering agents showing the selectivity of the MIP(ANI)/GCE sensor. Finally, the non-imprinted polymer (NIP)-based sensor was prepared to control the MIP(ANI)/GCE performance.

Development and Validation of a Rapid and Reliable HPLC-FLD Method for the Quantification of Ciprofloxacin and Enrofloxacin Residues in Zea mays

The accumulation of antibiotics by plants is a currently concern associated to yield reduction and transference of antibiotic residues along the food web. Maize is a staple food in many parts of the world; it is also considered an important ingredient in animal nutrition. Considering the lack of validated analytical methods for the analysis of ciprofloxacin (CIPRO) and enrofloxacin (ENRO) in the shoot of Zea mays maize, we developed a reliable reversed-phase high-performance liquid chromatography method with fluorescence detection (HPLC-FLD). This method was validated for linearity, matrix effects, precision, accuracy, limits of quantification (LOQ) and detection (LOD), and robustness. The analytical curves were linear with coefficient of determination (R2 ) of 0.9907 for CIPRO and 0.9962 for ENRO. The LOD values were 16.65 and 6.57 μg kg−1 for CIPRO and ENRO, respectively, whereas LOQ values were 50.44 μg kg−1 (CIPRO)and 19.92 μg kg−1 (ENRO). HPLC-FLD also displayed good precision and accuracy. Therefore, the proposed method can be considered a reliable and useful tool for the analysis of ciprofloxacin and enrofloxacin in the shoot of maize.

A novel electrochemical sensor for monitoring ovarian cancer tumor protein CA 125 on benzothiophene derivative based electrodes

COVID-19 crisis affects ovarium cancer patients seriously. Thus, it is vital to diagnose ovarium cancer, one of the most common types of cancer diagnosed and the causes of death of women around the world, at early stages. Herein, 5-(2-phenylbenzo[b]thiophen-3-yl) thiophene-2-carbaldehyde (PTTC)-based sensor is designed to detect CA-125 more precisely and rapidly via electrochemical methods. PTTC, novel benzothiophene derivative, is synthesized by electrophilic cyclization reactions and Pd-catalyst coupling reactions. Then, PTTC is dispersed homogeneously in Nafion solution, and an ink is obtained. This ink is transferred onto the glassy carbon electrode and CA-125 is incubated on this electrode. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy measurements are employed to determine sensitivity and reliability of CA-125 on PTTC based GCE electrode. The effect of CA 125 concentration, incubation time, scan rate studies are performed by CV to determine the optimum conditions. Optimum conditions are found as 3 μL PTTC loading, 5000 ng/mL CA125 antigen concentration and 30 min incubation time. Linear range of the PTTC based GCE electrode prepared at optimum conditions are obtained by DPV as 1–100 ng/ml.Limit of detection and limit of quantification values were obtained as 0.0096 ng/mL and 0.0288 ng/mL, respectively. Interference and artificial serum results reveal that this electrode is a promising electrode for CA125 antigen determination for the ovarium cancer. PTTC is a novel and unique material for the detection of ovarium cancer antigen CA-125 and promising for CA-125 antigen detection.