Analyst最新文献

A simple and sensitive microextraction protocol based on the use of unmodified cellulose was developed for the simultaneous extraction of 107 prohibited compounds and their metabolites from 20 µL of serum and plasma. Sample preparation consisted of spotting 20 µL of serum/plasma onto a cellulose card, followed by extraction of the analytes with 500 µL of a methanol/acetonitrile (1 : 1, v/v) mixture for 20 min. The extracts were analyzed by liquid chromatography coupled to high-resolution mass spectrometry. The entire workflow was validated in terms of selectivity (no interferences were detected at the retention times of the target analytes), sensitivity (limits of detection in the range of 0.08–7.50 ng mL⁻¹) carry-over (no signals in the negative sample injected after the positive sample at high concentration), matrix effect (10–28%), extraction yield (42–89%), and extract stability (the analytes were stable for at least 72 h in the autosampler at 10 °C). The method was successfully applied to the analysis of samples containing the compounds at low nanogram per milliliter range, demonstrating its effectiveness for doping control purposes. Stability studies showed that the compounds were stable for at least 3 months at −20 and 4 °C in serum and plasma samples. In contrast, at 22 °C several thiazide-based compounds were completely degraded after 4 weeks; FG2216 was no longer detectable after 7 weeks; S6 and RAD140 were no longer detectable after 9 weeks, whereas trenbolone was completely degraded after 14 weeks. The other compounds were still visible for the entire study period, with variations in the range of 37–56%.

Intraocular lenses (IOLs) are implanted into the eyes during cataract surgery to improve vision. A rare complication following IOL implantation is the formation of crystallized deposits on the lenses, which significantly impair vision, necessitating subsequent surgical IOL exchange. Preventing these deposits from forming is critical, but this requires definitive molecular assignments of the crystals and knowledge of their mechanism of formation. Determining this information presents a significant analytical challenge due to the low numbers of crystals and curvature of the IOLs that limit use of conventional methods. Here, we report the development of multiple complementary analytical methods to characterize IOLs explanted from human patients and attain insight into the chemical identity and mechanism of the deposits. Initial elemental analyses using energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) revealed that IOL crystals contained calcium, phosphorus, and sodium and provided quantitative ratios between elements. Subsequent Raman spectroscopy identified carbonate in the crystals as well. An innovative single-crystal X-ray diffraction (XRD) method with integrated Rietveld analysis was then developed, which conclusively determined that IOL crystals were composed of substituted hydroxyapatite. Collectively, the data obtained from EDS, XPS, XRD, and Raman indicate that IOL deposits are composed of crystalline Ca₉Na(PO₄)₅(CO₃)(OH)₂ layered with amorphous calcium phosphate. This structure is similar to bone, suggesting that a similar ossification mechanism is followed. The robust analytical methods developed herein provide the most comprehensive characterization of IOL crystals to date and signify that the microenvironment of the eye is conducive to bone mineralization pathways that induce crystal formation on IOLs.

Correction for ‘Light-activated nanocomposite thin sheet for high throughput contactless biomolecular delivery into hard-to-transfect cells’ by Hima Harshan Padma et al., Analyst, 2025, 150, 860–876, https://doi.org/10.1039/D4AN01331J.