Analytical Letters

Bolundut, Liviu; Pop, Lidia; Bosca, Maria; Pascuta, Petru; Stefan, Razvan; Culea, Eugen; Popa, Adriana

doi: 10.1080/00032719.2024.2326173pmid: N/A

Abstract This work reports the effect of adding Sm2O3 and silver nanoparticles, in small quantities up to 1 mol%, on the optical and structural properties of the B2O3-Li2O glass-ceramic system. The X-ray diffraction patterns of the samples show the presence of small quantities of the B2O3 crystalline phase, in addition to a major amorphous phase. Various structural units like BO3, BO4, and LiO4, present in the samples network, are responsible for the absorption bands from the FT-IR spectra. The optical spectra provided valuable information such as the identification of the observed electronic transitions, the energy gap, the refractive index, and metallization values. The luminescence data show the fact that with the addition of metallic NPs the quenching phenomenon can be observed after 0.5 mol% samarium ions. The studied systems are interesting for optical and semiconducting devices.

Li, Yan; Li, Yaru; Wu, Fubin; Zhou, Jie; Wang, Yaoyao; Li, Guoliang; Lan, Jing; Zhao, Zongshan; Shi, Rongguang

doi: 10.1080/00032719.2024.2333329pmid: N/A

Abstract Hydrogen peroxide (H2O2) is widely used in the food industry as a bactericide due to its strong oxidizing ability. However, excess H2O2 in food can lead to chronic diseases, making it necessary to develop a rapid monitoring method. An electrochemical electrode based upon a glassy carbon electrode (GCE) modified with combined covalent organic framework (COF) and amino-modified multi-walled carbon nanotubes (MWNT-NH2) has been developed. The modifier was prepared by assembling the COF onto the surface of MWNT-NH2. Under optimal conditions, the performance of the modified electrode was evaluated by differential pulse voltammetry (DPV) with a linear range from 20 to 140 μM and a detection limit of 0.14 μM. In addition, the modified electrode had good stability and reproducibility. Good selectivity in presence of potential interferences and the successful application for the determination H2O2 in environmental water and chicken feet suggest its potential for practical analysis.

Khrushchev, A.Yu.; Gulyaeva, A.Yu.; Bondarenko, V.O.

doi: 10.1080/00032719.2024.2334635pmid: N/A

Abstract A simple, rapid and sensitive surface enhanced Raman spectroscopy (SERS) method is described for the determination of fenbendazole (FBZ) residues in milk and fermented dairy products using yogurt and curd as examples. An extraction method was used to purify the samples from interfering components of the matrix. 5-Nitrothiabendazole, which has similar physicochemical properties, was used as an internal standard. The detection limits for milk were 1.8 nM, 8.8 nM for yogurt, and 13.5 nM for curd. Using partial least squares (PLS), a calibration model was built for the determination of fenbendazole from 100 to 1000 nM. The root-mean square error of calibration (RMSEC) and the root-mean square error of prediction (RMSEP) were 39.4 and 46.5 nM, respectively. The recovery rate was from 97% to 120% and the relative standard deviation was less than 5.0%. The difference between this technique from the widely used liquid chromatography–mass spectrometry (LC–MS) method is in the reduction in time for preliminary sample preparation and significantly lower costs for reagents and consumables. The article examines the influence of order when mixing reagents in a SERS experiment, which is an important tool for optimizing the sensitivity and reproducibility of the method. It was shown for the first time that when various alkaline earth metal chlorides were used for agglomeration of silver nanoparticles (AgNPs), a change in the ratio of peak intensities of the two analytes in the solution was observed. This phenomenon may be used to increase the selectivity of SERS analysis of multicomponent samples.

Thawornpan, Pongsakorn; Weeraphan, Churat; Thanapongpichat, Supinya; Saechan, Charinrat; Wanichsuwan, Worrawit; Srinoun, Kanitta; Tansila, Natta; Verathamjamras, Chris; Champattanachai, Voraratt; Chokchaichamnankit, Daranee; Srisomsap, Chantragan; Svasti, Jisnuson; Buncherd, Hansuk

Wang, Jinmei; Fei, Guoxing; Zheng, Peichao; Yan, Nantian; Chen, Guanghui; Li, Wei; Dong, Daming; Guo, Lianbo

doi: 10.1080/00032719.2024.2333341pmid: N/A

Abstract Solution cathode glow discharge atomic emission spectrometry (SCGD-AES) using wide-bandpass (10-nm) interference filters (IF) as a spectral discrimination device was used for the determination of thallium (Tl) in surface water. The use of wide-bandpass interference filters greatly reduces the cost of traditional detection instruments. The influence of solution flow rate, discharge current and pH on the detection limit was characterized. Moreover, matrix effect experiments were performed to study the effect of different concentrations of Na+, K+, Ca2+, and Mg2+ on the Tl signal intensity. Using a solution flow rate of 2.8 mL/min, a discharge current of 50 mA, and pH of 1.0 with HNO3 as the supporting electrolyte, SCGD coupled with an interference filter provided a detection limit of 7.76 μg/L for Tl in water samples, comparable to traditional SCGD-AES. Furthermore, the spiked recovery rate of Tl is quantitative in real water samples and comparable to the performance of inductive coupled plasma – optical emission spectrometry (ICP-OES).

Wu, Yelu; Tang, Weiyang; Zhou, Jian-Liang; Xie, Tian

doi: 10.1080/00032719.2024.2333330pmid: N/A

Abstract 3,4-Dihydroxybenzaldehyde (DHB) is a highly effective water-soluble compound in the traditional Chinese medicine Salvia miltiorrhiza Bge. Which demonstrates clear therapeutic effects against a variety of diseases. Therefore, the development of a selective approach for the separation of 3,4-dihydroxybenzaldehyde is of great significance. In this study, electro-driven extraction combined with multi-stage extraction technology was employed for the first time to separate 3,4-dihydroxybenzaldehyde from S. miltiorrhiza Bge. Decoction (Recovery ≥ 46.09%). Five long-chain fatty alcohols were selected as the supported liquid membrane (SLM) in the electro-driven extraction. Factors influencing extraction efficiency, including pH, voltage, and extraction time, were optimized using a design of experiments. Under the optimal conditions, the linearity of 3,4-dihydroxybenzaldehyde ranged from 0.01 to 100 μg·mL−1), with limits of detection (LOD) and quantification (LOQ) of 5 and 17 ng·mL−1, respectively. The precision of electro-driven liquid membrane extraction for 3,4-dihydroxybenzaldehyde was below 8.42%. This paper reports novel electro-driven liquid membrane extraction for selectively isolating 3,4-dihydroxybenzaldehyde from S. miltiorrhiza Bge.

Jiang, Chao; Li, Yang; Zhang, Xinguang; Shan, Yuting; Ma, Cuiping; Shi, Chao

doi: 10.1080/00032719.2024.2326984pmid: N/A

Abstract Exponential amplification reaction (EXPAR) enables extremely rapid nucleic acid measurements. However, the nonspecific amplification in EXPAR limits its application, especially for low abundance target nucleic acids. Herein, polyethylene glycol 200 (PEG200), a widely available small-molecular cosolute, is described to suppress this nonspecific amplification. This cosolute generates molecular crowding and reduces the solution water activity, thereby weakening the template-template interactions and catalysis of enzymes, the major causes of nonspecific amplification. The additional of PEG200 greatly reduces the background and thereby improves the sensitivity of EXPAR by 4 orders of magnitude without extending the analysis time. Hence, the determination of target miRNAs at 1 aM was obtained within 20 min, outperforming most conventional strategies. This work provides an efficient and affordable strategy of applying water soluble cosolutes to eliminate the nonspecific amplification in EXPAR, which is expected to be widely employed to eliminate the background in nicking enzyme assisted amplification (NEAA).

Liu, Tongtong; Han, Weina; Wang, Lulu; Hou, Xiaoyu; Cao, Jin

doi: 10.1080/00032719.2024.2327626pmid: N/A

Abstract The aim of this study was to optimize the extraction conditions of 15 preservative allergens from skincare products using response surface methodology (RSM) and determination by gas chromatography – tandem mass spectrometry (GC-MS/MS). The optimal parameters were: 50% acetonitrile (ACN) (% v/v), a solvent/sample ratio of 80, and an extraction time of 10 min. The method provided good linearity (R 2 ≥ 0.990) from 0.01 to 2 µg/mL with low limits of detection (0.02–0.2 mg/kg) and quantification (0.04–1 mg/kg). Recoveries ranged from 70.1 to 125.6% and the relative standard deviations (RSDs) varied from 2.0 to 14.9%. The method was successfully applied to eighty skincare products to accurately quantify these preservatives allergens.

Ajayi, David Taiwo; Teepoo, Siriwan

doi: 10.1080/00032719.2024.2327638pmid: N/A

Abstract Milk is a major dietary source of calcium; thus, accurate and precise quantification of calcium in milk and other dairy products is necessary for quality control. Conventional instrumental methods are sensitive and accurate but require expensive instrumentation, sample pretreatment, skilled personnel, and a long detection time. Herein, a microfluidic paper-based analytical device (µPAD) was developed to quantify calcium ions (Ca2+) in milk using a smartphone as a detector. The method utilized a complexometric reaction between Ca2+ and ethylene diamine tetraacetic acid with murexide as an indicator. The response was the average color intensity at the detection zones measured using the Color Picker application. The proposed µPAD exhibited a good linear detection range (1 to 10 mM), a low detection limit of 0.42 mM, and a short analysis time of 2 min. The determination of Ca2+ in milk samples using the proposed µPAD was consistent with a potentiometric method. The proposed µPAD demonstrates many advantages, including rapid detection, acceptable accuracy, low cost, low sample volume, and suitability for on-site quantification of Ca2+ in real samples.

un-Nisa, Mehr-; Talpur, Farah Naz; Chandio, Zaheer Ahmed; Waghani, Amrat; Razzaque, Noshad; Kunbhar, Sobia

doi: 10.1080/00032719.2024.2328364pmid: N/A

Abstract The biodegradation of pymetrozine pesticide was investigated with Pleurotus eryngii white rot fungus (WRF). The biomass was characterized by Fourier-transform infrared spectroscopy (FTIR) and scanning electrode microscopy (SEM) to verify surface functionality and morphology. FTIR results revealed fungal biomass is rich with multiple functional groups while SEM analysis showed that the surface of fungal biomass is irregular, porous, rough and heterogeneous. Bioremediation of pymetrozine with Pleurotus eryngii was monitored using ultraviolet-visible spectroscopy. The Box Bhenken Design optimization showed that Pleurotus eryngii degrades 93.3% of 0.20 mM pymetrozine at pH 5. Gas chromatography–mass spectrometry (GC-MS) was carried out to identify major metabolites formed during biodegradation of pymetrozine. Based on these results, pymetrozine was transformed to nicotinaldehyde and 4-amino-6-methyl-4,5-dihydro-2H- [1,2,4] triazine-3-one (AMDT).