The Journal of Automatic Chemistry最新文献

Projects that require analytical support can evolve from a number of different situations, for example new molecular entities from drug discovery; process changes; packaging changes; site changes; line extensions; and inlicensed projects and compounds. Laboratory automation has been shown to provide a viable and practical solution to assisting in analytical development. However, it is not always the most logical answer. A truly flexible and responsive analytical unit will make a decision on a case-by-case basis, when faced with a new project, whether it is best to: automate some or all aspects/testing involved; contract out to a reputable and approved contract research organization (CRO); hire temporary help; use available in-house resources; use a combination of the options shown above (for example to evaluate the complexity of the new project versus what the in-house resources are currently working on). The paper discusses the advantages and disadvantages of the various options with respect to providing analytical support and suggests optionsfor the most effective use of resources. The role of automation as one of the important tools in the arsenal of these options is highlighted.

An automated Cobas Fara method was developed determining the activity of recombinant M. thermophila laccase (rMtL). The chromogenic substrate used was syringaldazine. Under aerobic conditions, rMtL catalyses the oxidation of syringaldazine forming tetrametoxy-azo bis methylene quinone. The developed violet colour was measured kinetically at 530 nm as an expression of the enzyme activity, rMtL is a very sensitive oxidoreductase, therefore many factors had to be carefully controlled in order to get a robust analytical assay. In order to stabilize rMtL, PEG 6000 was added to the enzyme dilution medium. Furthermore, Triton X-I00 was included in the enzyme incubation solution.The analytical as well as technical conditions have been optimized, resulting in a method with good precision, sensitivity and speed of analysis. The Michaelis-Menten constant, K(m), was determined to be 22muM syringaldazine. LOQ was determined to be 0.010 Uml(-1), LOD to be 0.0002 Uml(-1) The analytical range of the enzyme dilution curve was from 0.01 to 0.044 Uml(-1) The repeatability was 1.9%, the reproducibility 3.1%. Testing the robustness of the method showed that the most sensible factors in the rMtL analysis in decreasing range were: incubation temperature, concentration of Triton X-I00, molarity and pH of the incubation buffer, and finally the concentration of syringaldazine.

C-reactive protein (CRP) levels were measured using a new particle-mediated immunoassay. Tests for precision and linearity of this method gave satisfactory results. The minimum sensitivity of the assay was 1 ng/ml. Interference by bilirubin (<220mg/l) and haemoglobin (<20g/l) was not observed. Using this method, CRP was assayed as a means of monitoring for infection in newborns up to 72 h after delivery. The pattern of time course elevation curves was similar for both groups (10 healthy subjects and 26 patients), but the serum CRP (ng/ml) of infected newborns rose significantly higher than in healthy subjects at 24 h after birth. The rate of increase of CRP (CRP; ng/ml/h) may be a more useful parameter to detect infection, since a significant change in CRP was apparent only 12 h after birth. The reported method was reliable and the parameters obtained were considered clinically useful for early detection of infection.

Ion mobility spectrometers (IMS) are small, lightweight, extremely robust devices with low power requirements, no moving parts, no absolute requirement for gases or vacuums, that can be operated at ambient temperatures and pressures, and yet are capable of measuring vapour phase concentrations of organic chemicals at very low levels (sub-mug/l). IMS are capable of analysing complex mixtures and producing a simple spectral output. Volatile components produce measurable negative and positive product ions in the spectrometer through chemical ionization. The spectra produced are essentially the vapour phase fingerprints of the target molecules/mixture. Quantitative data can be obtained provided instrument response is within the linear dynamic range of these instruments, but most practical applications of IMS have used the technology in a qualitative manner in situations which require just an above/below threshold or positive/ negative response.In the manufacturing industry there are many examples where the aroma/odour of raw materials has safety or product quality implications. IMS was not developed to replace traditional methods of analysis, e.g. GC/MS or sensory panels, but rather to provide a rapid, qualitative response complementary to more established methods. This paper reports on the use of a hand-held ion mobility spectrometer to characterize the vapours produced by volatile organic compounds,fresh herbs and retail spice mixtures at ambient temperature and pressure. The results show that by monitoring in both ion acquisition modes, ion mobility spectrometers are capable of discriminating between a wide range of products.