Combination of Si@UiO-66-NH2 paper-based thin film microextraction with direct solid-state spectrofluorimetry for extraction and determination of estradiol in urine.

BACKGROUND

Determination of the estradiol hormone in urine is crucial for evaluating congenital adrenal hyperplasia, certain hormone-producing ovarian tumors, polycystic ovary syndrome, liver disease, pregnancy, and infertility. On the other hand, steroid hormones can have destructive effects on the environment, animals, and the endocrine system of humans. Consequently, accurately measuring this hormone's concentration in trace amounts is essential for environmental safety and human health. In this study, a UiO-66-NH2 paper-based thin film was fabricated as a novel sorbent and optimized for the extraction and determination of estradiol, followed by direct analysis with solid-state spectrofluorimetry.

RESULT: The UiO-66-NH2 paper-based thin film was fabricated by the sol-gel method, and the fabrication conditions were optimized. After confirming the chemical structure and morphology of the thin film, the intra- and inter-batch reproducibilities of thin film fabrication were obtained as 4.6 % and 7.5 %, respectively. The extraction method was optimized, and the optimal values for sample pH, rotation speed, time, and temperature were obtained as 6, 400 rpm, 30 min, and 40 °C, respectively. This analytical method effectively measures the amount of estradiol in diluted urine. The method's intraday and interday recovery values were between 95.2 % and 103.3 %, and the intraday and interday relative standard deviations were less than 4.4 % and 7.3 %, respectively. The limit of detection and the limit of quantification values were obtained as 10 and 18 ng mL-1, respectively.

SIGNIFICANCE: By directly coupling the new sorbent with the solid-state spectrofluorimetry (SSF) method in this study, the requirement for thermal or solvent desorption has been eliminated. The proposed method was cost-effective, simple, and fast, and its application has also been evaluated in a real sample. In addition, this method was green, and its greenness has been confirmed using three different tools.