Analytical Letters

Guo, Yawen; Liu, Shuyu; Tang, Yayun; Zhu, Yali; Xie, Kaizhou; Xie, Xing

doi: 10.1080/00032719.2023.2248308pmid: N/A

Abstract This paper presents a novel and reliable approach for the determination of tilmicosin residues in poultry muscle and pork via gas chromatography–tandem mass spectrometry after precolumn derivatization. The samples were subjected to a quick, easy, cheap, effective, rugged, and safe preparation method, solid-phase extraction, hydrogenation, gel chromatography separation, acid hydrolysis, and derivatization with pyridine and acetic anhydride. For the blank spiked samples at the limit of quantification, 0.5 times the maximum residue limit (MRL), the MRL, and 2.0 times the MRL, the recoveries were from 76.91 to 87.99% with a precision of 2.04–5.47%. The limits of detection and quantification were 2.3–4.4 and 6.2–9.8 µg kg−1, respectively. The protocol was validated and real samples analyzed to demonstrate its practical application.

Wang, Rui; Qi, Shiyong; Zhang, Jingdong; Ren, Haotian; Xie, Linguo; Liu, Chunyu

doi: 10.1080/00032719.2023.2248530pmid: N/A

Abstract The incidence of calcium oxalate (CaOx) urolithiasis between men and women is considerably different. However, the full-scale metabolic changes between genders with CaOx urolithiasis have not been reported. The metabolic profiles in 112 urine samples obtained from 61 males and 51 females diagnosed with CaOx stones were characterized using electrospray ionization-mass spectrometry (ESI-MS). Univariate, multivariate, and bioinformatic analyses were employed to reveal the differential metabolites and perturbed metabolic pathways between genders. In total, 30 dysregulated metabolites were identified as differential metabolites between males and females with CaOx urolithiasis. The primary metabolic pathways were caffeine metabolism, metabolic pathways, and biosynthesis of amino acids. Furthermore, 10 potential metabolites which were mostly contributed to separating the males and female were selected using feature weight calculation. These compounds included creatinine, 3-methylhistidine, n-acetylneuraminic acid, decanoyl-l-carnitine, cortisone, nicotine, 1-methyluric acid, androsterone sulfate, citramalic acid, and 1,7-dimethylxanthine. Finally, a subset of the differential metabolites was identified by receiver operating characteristic (ROC) curve analysis, including creatinine, 3-methylhistidine, n-acetylneuraminic acid, decanoyl-l-carnitine, and 1-methyluric acid (area under the curve = 0.924, 0.844, 0.846, 0.814, 0.814). These metabolites had higher risks in the CaOx stone formation of males than females. The study showed that there were a group of differential metabolites between the males and females with CaOx stones. A subset of these compounds was more closely and positively related to renal stone formation in males than females. Moreover, these metabolites may be the cause of the differences in the incidence of CaOx urolithiasis between genders.

Zhang, Yuding; Xie, Mengyao; Ma, Gongcheng; Chen, Huajie; Li, Dai; Guan, Lijiao; Zhang, Xianfen; Wu, Jiyong; Huang, Saipeng

doi: 10.1080/00032719.2023.2250032pmid: N/A

Abstract Ferric ion (Fe3+) serves as an essential and indispensable inorganic element in various biological process. Excess Fe3+ is harmful for biological systems and human health. Herein, highly sensitive carbon quantum dots (Fe-CQDs) for ferric ions were synthesized by a high-efficiency, one-step hydrothermal route utilizing L-arginine and citric acid. The prepared Fe-CQDs exhibited good water solubility, high photostability, and bright blue florescence with relatively high quantum yields (QYs) over 21.33% and a Stokes shift exceeding 100 nm. The functionalized Fe-CQDs offer rapid, sensitive, and selective recognition of Fe3+ with a linear relationship from 0.6 to 80 μM and a low detection limit of 0.2 μM. Moreover, the synthesized Fe-CQDs illustrated strong anti-interference properties in samples and buffer solutions. The developed sensor demonstrated high biocompatibility and was successfully applied for intracellular Fe3+ determination in SHSY5Y and HT22 cells, illustrating excellent imaging application. The present work provides a promising platform for the early clinical diagnosis of Fe3+-associated diseases.

Sun, Qianran; Li, Yongli; Su, Youzhi; Liu, Jun

doi: 10.1080/00032719.2023.2250026pmid: N/A

Abstract A simple method for the determination of 19 types of phthalate acid ester plasticizers in raw textile solid waste has been developed by employing ultrasonic extraction coupled with gas chromatography – tandem mass spectrometry (GC-MS/MS). The evaluation of the plasticizers in several textile solid wastes showed that the levels were high, especially dimethylglycol phthalate. The extraction solvent, ultrasonic time, and ultrasonic temperature were optimized. Hexane was adopted as the extraction solvent, and ultrasonic extraction was performed at 20 °C for 30 min. A linear relationship from 0.02 to 1000 ng/mL was obtained with correlation coefficients(r) greater than 0.996. The limits of quantitation were from 0.08 to 30.70 µg/L based upon a signal-to-noise ratio (S/N) of 10. The recoveries were from 90.1% to 108.9% and the relative standard deviation between 0.78% and 9.43%. The method can be used for rapid screening and quantitative analysis of textile solid waste due to the simple, sensitive, and accurate assay.

Khoshbin, Zahra; Taghdisi, Seyed Mohammad; Danesh, Noor Mohammad; Lavaee, Parirokh; Khakshour Abdolabadi, Ali; Abnous, Khalil

doi: 10.1080/00032719.2023.2250027pmid: N/A

Abstract Here, a simple colorimetric strategy was developed to monitor lead ion (Pb2+) based upon the catalytic function of gold nanoparticles (AuNPs) regulated by the aptamer strands. The peroxidase-like activity of AuNPs was prevented by the aptamers through masking their surface. Thus, the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) did not proceed. By adding Pb2+, the aptamer-Pb2+ complex was formed that released the aptamer from the surface of AuNPs. Hence, free AuNPs initiated the oxidation of TMB that changed the solution color from colorless to blue. A linear concentration range was achieved from 0.2 to 200 nM with a detection limit (LOD) of 0.056 nM for Pb2+ detection. The aptasensor successfully monitored Pb2+ in drinking water, milk, and human serum. With the properties of sensitivity, simplicity, and naked-eye target monitoring, the developed aptamer-included biosensor (aptasensor) is suitable for food safety, health care application, and environmental monitoring.

Cargnin, Rejane S.; Lorenzoni, William C.; do Nascimento, Paulo C.; de Carvalho, Leandro M.; Somavilla, Ezequiel A.; Cravo, Margareth C. C.; do Nascimento, Luis A. H.

doi: 10.1080/00032719.2023.2250028pmid: N/A

Abstract Polycyclic aromatic hydrocarbons (PAHs), as well as their sulfur (S-PAHs), oxygen (O-PAHs), and nitrogen (N-PAHs) analogs were evaluated in the fumes of asphalt samples produced in Brazilian refineries. The fumes were generated using a laboratory-constructed device for extraction and collection (DEC). Two previously published methodologies for PAHs and S-PAHs evaluation by high-performance liquid chromatography with diode array detection (HPLC-DAD) were employed, together with a new methodology for O and N-PAHs. A total of 54 compounds were assessed. The samples included 31 compounds within the scope of this study, and the emissions were highly dependent upon the heating temperature and asphalt source.

Cheng, Wenhan; Lee, JianHong; Miller, Emily; Jackson, Bryan

doi: 10.1080/00032719.2023.2251160pmid: N/A

Abstract The pheomelanin precursor 5-S-cysteinyldopa (5SCD) exhibits promising potential as a urinary and serum biomarker for melanoma. Nonetheless, it is important to note that 68.8% of early-stage melanoma cases remained undetected when employing 5SCD as a biomarker, underscoring the inadequacy of its efficacy, especially in identifying stage I/II melanoma. In lieu of detecting free 5SCD, the hydrolysis products of pheomelanin, namely, 4-amino-3-hydroxyphenylalanine (4-AHP) and 3-amino-4-hydroxyphenylalanine (3-AHP) offer the prospect of achieving heightened sensitivity and broader scope in early-stage melanoma diagnosis through direct chemical processes. This study introduces an innovative gas chromatography-mass spectrometry (GC-MS) methodology to identify early-stage melanoma by comparing the concentrations of AHPs across 80 stage I/II melanoma patients against 32 healthy controls. The approach demonstrated linear response within the 0.5–20 μg/mL range for reference AHPs detection. The urine levels of AHPs were 1.3 ± 0.5 μg/mL in the control/volunteer group (n = 32), 8.1 ± 1.6 μg/mL in stage I and II melanoma patients (n = 28), and 6.3 ± 1.9 μg/mL in stage II melanoma patients (n = 52). The findings unequivocally underscore the diagnostic promise of AHPs as a robust tool for early-stage melanoma assessment in laboratory medicine.

Tao, Wenyan; Ye, Mingguo; Liu, Ying; Lin, Zhenjia; Wang, Chenchen; Huang, Yujun; Pan, Dawei

doi: 10.1080/00032719.2023.2251620pmid: N/A

Abstract An electrochemical sensor based upon a poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT-PSS) co-polymer film with gold nanoparticles (AuNPs) modified microelectrode is reported for the determination of Fe(III). Scanning electron microscopy images showed that the AuNPs were immobilized on gold (Au) microelectrode by formation of a nanofilm with PEDOT-PSS. The individual particles and their cluster-like aggregates provide a larger active electrochemical area and higher conductivity, which facilitates the determination of Fe(III). Electrochemical impedance spectroscopy (EIS) shows the AuNPs/PEDOT-PSS/Au microelectrode possesses high conductivity. A low detection limit of 0.01 µM Fe(III) was obtained using the modified microelectrode by differential pulse voltammetry (DPV) due to its large specific surface area, high conductivity, and the presence of more active sites. The optimized pH of the supporting acetate buffer was 2.0. The AuNPs/PEDOT-PSS/Au provided a linear range from 0.0119 μM to 7.14 μM. The modified electrode was successfully employed for the the determination of total dissolved iron in river water from Three Gorges with satisfactory results.

Dash, Manaswini; Singh, Subhashree; Sahoo, Suprava; Kar, Basudeba

doi: 10.1080/00032719.2023.2253341pmid: N/A

Abstract Piper longum L., known as long pepper, is an important species of the family Piperaceae due to its commercial and medicinal properties. However, its volatiles have only been analyzed by gas chromatography–mass spectrometry (GC–MS). The present study focused upon the precise characterization of Piper longum L. leaf volatiles for the first time by two-dimensional gas chromatography–time-of-flight mass spectrometry (GC × GC–TOF-MS). A total of 104 constituents accounting for 91.79% of the essential oil were identified due to the enhanced chromatographic separation and mass spectral deconvolution of GC × GC–TOF-MS, of which 20 constituents were reported first time. The identified constituents were categorized into alkanes (4.07%), alkenes (0.12%), aldehydes (0.52%), alcohols (6.87%), esters (2.40%), ether (0.26%), ketones (3.78%), monoterpene hydrocarbons (15.48%), oxygenated monoterpenes (4.21%), sesquiterpene hydrocarbons (22.68%), oxygenated sesquiterpenes (30.4%), diterpenes (0.75%), phenylpropanoids (0.14%), and fatty acids (0.15%). Among the classes, oxygenated sesquiterpenes were found to be the major group with E-nerolidol as the dominant compound (18.92 ± 0.02%), followed by β-pinene (5.41 ± 0.02%), α-pinene (4.44 ± 0.02%), and Z-caryophyllene (3.14 ± 0.03%). Additionally, GC × GC–TOF-MS separated 24 coeluting constituents which were unresolved using the one-dimensional GC column, hence justifying to be a noteworthy approach for analysing volatiles by two-dimensional GC system. The in-depth terpenic characterization may influence the overall quality of the oil as well as allow the future improvement of the species.

Liu, Ge Lin; Hou, Hao Zhe; Su, Yan; Peng, Yao Jia; Wu, Yin Liang; Wang, Jian Ping

doi: 10.1080/00032719.2023.2253938pmid: N/A

Abstract The residues of xylazine and its metabolite in foods of animal origin are dangerous to consumers, but there has been no enzyme-linked immunosorbent assay (ELISA) or ELISA-like method reported to determine them so far. In this study, molecularly imprinted microspheres with xylazine as the template were synthesized, and 2,6-dimethylaniline (the metabolite of xylazine) was used as a hapten to prepare a streptavidinated horseradish peroxidase-labeled conjugate. A direct competitive pseudo-ELISA was developed on a microplate for xylazine and 2,6-dimethylaniline in milk. Because biotinylated horseradish peroxidase was employed to enhance the signal, the limits of detection for xylazine (0.003 ng/mL) and 2,6-dimethylaniline (0.005 ng/mL) were increased by 16.7- and 14-fold, respectively, compared to a horseradish peroxidase-labeled conjugate. Moreover, this material may be reused three times. The analysis of milk samples was consistent with values obtained by liquid chromatography tandem mass spectrometry. This is the first paper reporting a molecularly imprinted polymer-based method for the determination of xylazine and its metabolites in food.