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A simple and ultrasensitive method for detecting Pb2+ using resin-enrichment combined with laser-induced breakdown spectroscopy assisted by laser-induced fluorescence.

We proposed a modified corner-cutting method for continuum background removal in laser-induced breakdown spectroscopy.

We proposed an improved algorithm based on the optimization of a combined atomic and ionic line algorithm for LIBS analysis.

Using an aspheric lens for laser focusing solves the energy dispersion caused by spherical aberration, reducing the plasma fluctuations.

A convenient LIBS approach was proposed to reduce the self-absorption effect of alkali and alkaline earth metal elements in soil.

Quantitative trace element analysis is crucial to a range of industries, including food, natural and man-made materials, and biomedicine. For this purpose, we here developed laser-induced breakdown spectroscopy (LIBS) with dried droplet sample pretreatment. This novel method is quantitative and especially suited to analyzing small solid samples with trace concentrations of low atomic number elements. The dried droplet pretreatment involves acid digesting the sample and allowing a droplet to dry on filter paper free of the analytes. LIBS was then performed on the dried droplet using pulsed laser ablation and spectroscopic detection from 200–1000 nm with 0.1 nm resolution. A standard addition approach was employed to quantify LIBS signals by adding known amounts of analytes into the droplets. The method was demonstrated by measuring sodium, potassium and calcium in four selected samples. All the standard addition calibration curves showed good linearity, with all regression coefficients >0.981 and relative standard deviation

Lineariifolianoids A–D (1–4), a rare class of unsymmetrical sesquiterpenoid dimers with xanthane and guaiane frameworks have been isolated for the first time from Inula lineariifolia. Notably, lineariifolianoid D (4) features the first exo-adduct of such dimers through a plausible Diels–Alderase catalyzed biogenetic pathway. Moreover, the absolute configuration of japonicone A (5) has been revised by the Flack method. The inhibitory effects of the new isolates on TNF-α-mediated L929 cytotoxicity have also been evaluated and only the exo-adduct lineariifolianoid D (4) displays the inhibitory property.