Ultrasound-assisted dispersive micro-solid-phase extraction based on N-doped mesoporous carbon and high-performance liquid chromatographic determination of 1-hydroxypyrene in urine samples

Rapid determination of hippuric acid as an exposure biomarker of toluene using a colorimetric assay and comparison with high-performance liquid chromatography

Occupational exposure to toluene is associated with health risks that require reliable monitoring methods. Hippuric acid (HA), a urinary metabolite of toluene, serves as a valuable biomarker for such exposure. Colorimetric methods for the quantitative determination of HA have gained prominence due to their simplicity, cost-effectiveness, and suitability for field application. In the present study, a simple colorimetric technique was optimized for the determination of HA in the urine sample, and compared with a usual HPLC technique. The central composite design (CCD) was applied to examine the effective parameters on the colorimetric determination of HA. The calibration curve for HA was established within the concentration range of 6 to 100 mg L-1 with R2 = 0.97. The detection limit (LOD) and quantification limit (LOQ) were determined to be 1.8 mg L-1 and 6 mg L-1 respectively. The relative standard deviation (RSD%) was less than 5%, and the recovery% (R%) was 90.5-100.1. The overall results showed good agreement between the colorimetric and HPLC results. There was a significant relationship between the results obtained from HPLC and colorimetric methods especially for higher concentration levels of HA (≥ 500 mg/g creatinine). In conclusion, our optimized colorimetric method is a simple, cost-effective, and rapid method for determination of HA in occupational exposure, which is comparable with the HPLC technique.

A novel and easy-to-construct polymeric l-glutamic acid-modified sensor for urinary 1-hydroxypyrene detection: Human biomonitoring of polycyclic aromatic hydrocarbons exposure

1-Hydroxypyrene (1-OHP), a metabolite of polycyclic aromatic hydrocarbons (PAHs), is a frequently used biomarker for assessing human exposure to PAHs. Therefore, the technology that provides a quick, simple, cost-effective, portable, accurate, precise, and reliable test is still in great demand. To the best of our knowledge, the creation of an electrochemical device based on poly(l-glutamic acid)-modified a screen-printed graphene electrode (poly(L-GA)/SPGE) for 1-OHP detection was described for the first time. The developed sensor was simply and rapidly manufactured via only a single step of electropolymerization. All the concerned parameters and electroanalytical conditions were studied to obtain the best performance of the methodology. Under optimal conditions, the 1-OHP sensing provided a linear range of 1-1000 nM with the limits of detection and quantification of 0.95 and 3.16 nM, respectively. Moreover, this developed sensor was successfully utilized by determining 1-OHP in human urine samples. In comparison with conventional methods, this newly proposed electrochemical methodology might be tremendously valuable for 1-OHP evaluation in environmental and occupational applications, leading to the early detection of illness risk linked to PAHs in the human body.

Recent Advances in Solid-Phase Extraction as a Platform for Sample Preparation in Biomarker Assay

Low levels of biomarkers and the complexity of bio sample make the analytical assay of several biomarkers a challenging issue. Suitable sample preparation run remain a vital part of the puzzle of diagnostic level. Enhancing the detection limit of bioanalytical methods start during the sample preparation procedure. A robust sample preparation method is needed to evaluate the number of biomarkers. As worldwide environmental issues attract expanding consideration, all the more harmless to the ecosystem investigations are liked. Solid-phase extraction (SPE) is an appealing strategy among the sample treatment methods due to the versatility of sorbent materials, less solvent consumption, and compatibility with analytical devices. Miniaturization of the SPE gives the chance to integrate the other analytical steps in a single run, known as an easy-to-use and effective method. SPE utilizes various SPE sorbent beds such as packed beads, porous polymer monoliths, molecularly imprinted polymers, membranes, or other magnetic form microstructures to achieve high surface-to-volume ratio and appropriate chemical properties effective extraction. Also, SPE is the methodology of interest to fulfill high recovery and efficiency demands. In this review, we intend to explain more recent methods for the rational design of SPE and miniaturized SPE to determine biomarkers from biological media. The headlines are subdivided into (1) packing materials in SPE, (2) setups for sample preparation by magnetic SPE, and (3) and future perspective for the application of SPE in sample preparation for analysis of biomarkers.

Solidified floating organic droplet microextraction coupled with HPLC for rapid determination of trans, trans muconic acid in benzene biomonitoring

Benzene is one of the carcinogenic compounds in the work environments. Exposure assessment of benzene through biological monitoring is an acceptable way to accurately measure the real exposure in order to conducting the health risk assessment, but it is always complicated, laborious, time consuming and costly process. A new sensitive, simple, fast and environmental friendly method was developed for the determination of urinary metabolite of benzene, trans trans muconic acid (t,t-MA) by dispersive liquid-liquid micro extraction based on solidification of floating organic droplet coupled with high-performance liquid chromatography with ultra violet detector. Central composite design methodology was utilized to evaluate the effective factors on the extraction output of the target metabolite. The calibration curve was plotted in the concentration ranges of 0.02-5 µg mL^-1. The precision and accuracy of the method were assayed via the relative standard deviation (RSD%) and relative recovery (RR%) using spiked samples with three replications. The RR% and RSD% of the optimized method were 86.9-91.3% and 4.3-6.3% respectively. The limit of detection (LOD) of the method was 0.006 µg mL^-1. The level of t,t-MA in real samples was ranged from 0.54 to 1.64 mg/g creatinine. We demonstrated that t,t-MA can be extracted and determined by an inexpensive, simple and fast method.