Gas chromatography-mass spectrometric (GC-MS) methods for drug analysis routinely employ derivatising reagents. The aim of this paper was to develop a method for the analysis of two recreational drugs, delta-9-tetrahydrocannabinol (Δ(9)-THC) and cocaine in hair samples using GC-MS, without prior derivatisation, thus allowing the sample to be reanalysed in its original form. An enzymatic digesti...

Analysis of chemical or biomolecular contents in a tiny amount of specimen presents a significant challenge in many biochemical studies and diagnostic applications. In this work, we present a single-layer, optofluidic device for real-time, high-throughput, quantitative analysis of droplet contents. Our device integrates an optical fiber-based, on-chip detection unit with a droplet-based microfl...

Surfaced enhanced Raman scattering (SERS) can discriminate between metal complexes due to the characteristic "spectral fingerprints" obtained. As a result, SERS has the potential to develop relatively simple and sensitive methods of detecting and quantifying a range of metal ions in solution. This could be beneficial for the environmental monitoring of potentially toxic metals (PTMs). Here, sal...

A novel nanosilver-deposited silica-coated Fe3O4 magnetic particle (Fe3O4@SiO2@Ag) with uniform size, good SERS activity and magnetic responsiveness was synthesized using amination polymer. The Fe3O4@SiO2@Ag magnetic particles have been successfully applied for ultrasensitive SERS detection of malachite green (MG) in water samples. The mechanism is that MG can be adsorbed on the silver surface ...

trans-Cyclopentane-modified PNA has been successfully utilized as a target capture strand to improve the detection limit of a known DNA detection assay, and provide high levels of mismatch discrimination.

A novel prepared mercuric ion PVC membrane sensor based on a Rhodamine B derivative (RND) as a selective sensing material was described. The sensor exhibited a specific fluorescent off-on response to Hg(2+), and showed a linear response over the Hg(2+) concentration range from 1.0 × 10(-9) to 2.0 × 10(-3)M with a very low detection limit of 8.1 × 10(-10)M in bulk method. The sensor has also bee...

An analytical method for simple and rapid determination of methylmercury in sediment and organism samples is described. The proposed method employs the oxygen combustion-gold amalgamation using Direct Mercury Analyser (DMA-80) after complete removal of MeHg by organic extraction and back extraction to an aqueous medium. DMA-80 instrument is equally suitable for the analysis of solid and liquid ...

Previous work using a large data set (no. 1, n = 5355) of carcass sponge samples from three large-volume beef abattoirs highlighted the potential use of binary (present or absent) Enterobacteriaceae results for predicting the absence of Salmonella on carcasses. Specifically, the absence of Enterobacteriaceae was associated with the absence of Salmonella. We tested the accuracy of this predictiv...

In this work we present an optical technique for characterizing sub-micrometric areas based on reflectivity of the light as a function of angle of incidence for the two pure polarizations s and p, covering a range of angles of incidence from -71.80° to 71.80° with a resolution of 0.1°. Circular areas with a diameter in the order of 600 nm can be characterized, and the spectra for the two polari...

We report a fast and simple high-speed liquid-chromatographic assay for serum retinol. Only 100 mul of serum is required. The lower detection limit is 50 mug/liter; linearity was demonstrated up to 1.50 mg/liter. On analyzing a serum pool eight times, a CV of 2.5% was obtained. Values by this method are compared with results obtained by a flurometric method [Clin. Chem. 16, 766(1970)].