companion document, entitled Guidance on Safety Performance Indicators (2003), will be published immediately
following the 2nd edition of the Guiding Principles. The Guidance on SPI is designed to assist relevant
stakeholders to establish programmes for assessing their own performance related to the prevention of,
preparedness for, and response to chemical accidents.
Amines are extremely important intermediates and end products of the chemical industry and are often obtained by hydrogenation of the
corresponding nitro compounds or imines. A search of the literature reveals, that hydrogenation of nitro compounds catalyzed by well-defined molecular complexes in aqueous solutions is rare.
Chemical composition of essential oil of Machilus Japonica Siebold & Zucc. (Lauraceae) from Vietnam were studied. The essential oil were obtained from the leaves of young plants (3-4 years) by hydrodistillation. The identification of the components was performed using GC, GC/MS. The main components in this species identified were α-phellandrene (60.2%), βphellandrene (10.5%), p-cymene (20.3%),
Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of one or more of these components. The separation of components is often performed prior to analysis
Anserinase (Xaa-methyl-His dipeptidase, EC 18.104.22.168) is a dipeptidase that
mainly catalyzes the hydrolysis ofNa-acetylhistidine in the brain, retina
and vitreous body of all poikilothermic vertebrates. The gene encoding
anserinase has not been previously identified. We report the molecular
identification of anserinase, purified from brain of Nile tilapia Oreochromis
The high specificity ofa-conotoxins for different neuronal
nicotinic acetylcholine receptors makes them important
probes for dissecting receptor subtype selectivity. New
sequences continue to expand the diversity and utility of
the pool of available a-conotoxins. Their identification
with increasing emphasis on mass spectrometry and micro-scale chromatography, which have benefited from recent
advances in resolution and capability.
Nowadays, Chromatography is the most versatile and widespread technique employed in modern chemical analysis and plays a vital role in the advancement of chemistry, biology, medicine and related fields of research. Because of the inherent simplicity and ease of operation, it can be used together with a wide range of detection systems, including electrochemical, photometric and mass spectrometry, being an invaluable laboratory tool for the separation and identification of compounds.
Now an established handbook of principles and techniques, this text develops an understanding of the relevance of four fundamental properties of the analyte: shape, polarity, charge and size, to the three key types of analysis: separation, identification and quantification. The third edition of Analytical Biochemistry has now been fully updated in content and format, making it even more accessible to students learning how to select analytical techniques and recognise their scope and limitations.
Jonathan Demme’s film is one of the most important films of the 1990s winning Oscars for best film,
director, actor, actress and adapted screenplay. This was groundbreaking because a film with such
lurid subject matter (it is the tale of two serial killers) had never achieved this status before. The film
could be described as a hybrid genre film mixing the police procedural/detective thriller genre with
the horror movie.
VOCs from process vents are, where possible, re-used within processes but this is dependent on
such factors as VOC composition, any restrictions on re-use and VOC value. The next
alternative is to recover the VOC calorific content as fuel and, if not, there may be a
requirement for abatement. A combination of techniques may be needed, for example: pre-
treatment (to remove moisture and particulates); concentration of a dilute gas stream; primary
removal to reduce high concentrations, and finally polishing to achieve the desired release
Many drugs have unknown, controversial or multiple mechanisms of action. Four recent ‘chemical genomic’ studies, using genome-scale collections of yeast gene deletions that were either arrayed or barcoded, have presented complementary approaches to identifying gene-drug and pathwaydrug interactions.
The fact that much of modern drug research is target-oriented obscures the long history during which the effects of drugs were discovered prior to identification of their targets. There remain many...
Paper consumption can represent significant costs associated with the communications and marketing
activities of a planned event. It is often considered a necessary cost of doing business. Yet, when looking at
a standard piece of paper, many of us do not consider the true cost of producing it. Conventional paper uses
chemicals that produce, along with the paper itself, harsh toxic substances and the living trees used to make
the paper provide priceless ecological services.
Scientists have long relied on the power of imaging techniques to help them
see things invisible to the naked eye and thus advance scientific knowledge. In
medicine, X-ray imaging and magnetic resonance imaging (MRI) have added a
level of insight beyond traditional lab tests into the workings of the human body
and identification of disease at its earliest stages. Microscopy, which has been in use
since the sixteenth century, is now powerful enough to detect, identify, track, and
manipulate single molecules on surfaces, in solutions, and even inside living cells....
Addition of Surrogates and Matrix Spiking Compounds in the Field: It is best to
add analytical surrogate and matrix spiking compounds into soils prior to sample
extraction, using water or a solvent. Method 5035A does not incorporate the addition
of these compounds prior to extraction in the field. Because this is an important
control check on the analytical process, it may be appropriate to incorporate a
procedure which adds surrogate and/or matrix spiking compounds prior to extraction
for some project/program DQOs.
the beginning, medicinal therapy consisteodf concoctions coadministered
with incantations. Little thought was given to dissecting out the
contributions of the pharmacology of the concoction from the spiritual
consequences of the incantations. Eventually, potions and extracts were
recognized to have predictable activity that could be observed and described
objectively. Then came the capacity to estimate potency,t o l eading
concentration and purification.
Hopke and co-workers (6), Heidam (7), Henry (8), and
Barrie and Barrie (9) applied principal component analysis
(PCA) to source identification, but Paatero and Tapper (10,
11) showed that PCA cannot provide a trueminimal variance
solution since they are based on an incorrect weighting. In
view of the limitations of PCA, a new technique, positive
matrix factorization (PMF), was developed for sources
identification and apportionment (12).
The complexity of the volatile organic compound (VOC)
mixture in the Houston area makes studies of the air quality
in that area very challenging. In this paper, a novel
factor analysis model, where the normal chemical mass
balance model was augmented by a parallel equation that
accounted for wind speed and direction, temperature,
and weekend/weekday effects, was fitted with a multilinear
engine (ME) to provide identification and apportionment
of the VOC sources at the La Porte Municipal Airport site
in Houston during the Texas Air Quality Study (TexAQS)
Some organic pest management strategies include
using crop rotations that disrupt the pest life cycle,
improving soil quality, practicing good sanitation,
using optimum planting densities, timing planting
and transplanting operations to avoid high pest
populations, employing biological control, and
growing resistant varieties. Approved pesticides
that have been listed in the grower’s OSP can be
used in organic production, but should be used as
judiciously and as specific to the pest organism
Prefractionation procedures facilitate the identification of lower-abundance
proteins in proteome analysis. Here we have optimized the conditions for
immobilized metal affinity chromatography (IMAC) to enrich for phos-phoproteins. The metal ions, Ga(III), Fe(III), Zn(II), and Al(III), were
compared for their abilities to trap phosphoproteins; Ga(III) was the best.
The isovaleric acid-emanating silkworm mutantskunk (sku) was first stud-ied over 30 years ago because of its unusual odour and prepupal lethality.
Here, we report the identification and characterization of the gene responsi-ble for theskumutant.