Chemical decontamination of methamphetamine and ephedrine using an activated peroxide-containing cleaning solution.

Manufacture and recreational use of methamphetamine can result in widespread chemical contamination throughout a property. Hydrogen peroxide (HO)-based cleaning products have shown success against a number of chemical contaminants including agents of chemical warfare, and biological contaminants such as anthrax. They are considered to be environmentally friendly and economically viable and, as such, are used by many companies within the methamphetamine decontamination industry.

Nitrosamine formation from the reaction of methamphetamine with gaseous nitrous acid.

Methamphetamine is the most commonly seized amphetamine-type stimulant (ATS) worldwide. Chemical residues associated with the use or manufacture of methamphetamine can persist in the air and surfaces in a property for over 5 years and potentially pose risks to the health and safety of the public. When a house is tested for contamination, the test focuses on the presence of surface methamphetamine residue; however, other hazardous chemicals may also be present, including methamphetamine precursors and reaction products.

The contribution of commercial fireworks to both local and personal air quality in Auckland, New Zealand.

Firework displays produce large amounts of particulate matter (PM), contributing to poor air quality in local areas. Since short-term exposure to particulate matter correlates with increased mortality risks, these celebrations may impact both human health and the environment. Little is known about the particulate matter produced from recreational fireworks, as most studies have focused on professional large-scale events.

Biodegradable chelating agent improves the survival of early larvae for shellfish aquaculture.

The toxicity of heavy metals commonly impacts the survival of crustacean and bivalve larvae in hatchery culture, and this has led to the widespread use of EDTA to decrease this toxicity. Since EDTA has a very poor biodegradability leading to potential persistent environmental effects, alternative methods to prevent heavy metal toxicity to shellfish larvae are needed. EDDS is a biodegradable potential alternative to EDTA for this application and was tested as a treatment of the seawater used for rearing aquaculture Greenshell™ mussel (Perna canaliculus) larval embryos in this study.

Identification and characterization of chemically masked derivatives of pseudoephedrine, ephedrine, methamphetamine, and MDMA.

The emergence of chemically masked illicit drugs represents a challenge to global initiatives that are working to prevent their manufacture and distribution. Targeted analytical techniques currently used by law enforcement to identify unknown materials rely on spectroscopic and spectrophotometric databases that do not currently include some of these compounds, making their identification challenging. This study aimed to update compound spectral libraries to aid in the rapid detection and identification of these masked drugs, as well as to provide insight into their synthetic procedures.

Examining the role of ethylenediaminetetraacetic acid (EDTA) in larval shellfish production in seawater contaminated with heavy metals.

Heavy metal pollution is a concern in many coastal locations where it is frequently deleterious to the survival of young shellfish. Consequently, a great number of commercial shellfish hatcheries around the world rely on the addition of ethylenediaminetetraacetic acid (EDTA) to seawater to ensure successful larval production. Despite the importance of this practice to global shellfish production the mode of action of EDTA in larval production remains undetermined.

A new analytical method to measure S-methyl-l-methionine in grape juice reveals the influence of yeast on dimethyl sulfide production during fermentation.

Background: Dimethyl sulfide (DMS) is a small sulfur-containing impact odorant, imparting distinctive positive and / or negative characters to food and beverages. In white wine, the presence of DMS at perception threshold is considered to be a fault, contributing strong odors reminiscent of asparagus, cooked cabbage, and creamed corn. The source of DMS in wine has long been associated with S-methyl-l-methionine (SMM), a derivative of the amino acid methionine, which is thought to break down into DMS through chemical degradation, particularly during wine ageing.

Potential for the Remediation of Methamphetamine Contamination Using Ozone.

The deposition of methamphetamine within indoor environments due to illegal activities can pose a health risk for occupants. Current cleaning techniques are costly and inefficient, calling for the development of alternative remediation methods. In addition, the fate of methamphetamine in indoor environments is largely unknown, negatively impacting our knowledge on the health risks associated with contaminated dwellings.

Hyperspectral and Color Imaging of Solvent Vapor Sorption Into Porous Silicon.

A porous silicon thin film photonic crystal (rugate) sample with both a radial gradient in the rugate reflectance band wavelength and two spatially separated pore-wall surface chemistries (methylated and oxidized) was monitored by hyperspectral and color imaging while it was dosed with vapors of acetone, ethanol, heptane, 2-propanol, and toluene at concentrations ranging from 100 to 3,000 mg m. The shift in the wavelength of the rugate reflectance band maximum at each position along a transect across the two surface chemistries, as derived from the hyperspectral imaging, could discriminate between the different solvents and concentrations of solvents, while the change in hue derived from the color camera data along an analogous transect did not provide discrimination. The discrimination between solvents was mainly due to the two different surface chemistries, and the gradient associated with the change in the rugate reflectance band wavelength did not affect the selectivity significantly.

Predicting effects on oxaliplatin clearance: in vitro, kinetic and clinical studies of calcium- and magnesium-mediated oxaliplatin degradation.

This study evaluated the impact of calcium and magnesium on the in vitro degradation and in vivo clearance of oxaliplatin. Intact oxaliplatin and Pt(DACH)Cl were measured in incubation solutions by HPLC-UV. A clinical study determined changes in plasma concentrations of calcium and magnesium in cancer patients and their impact on oxaliplatin clearance.

Capillary microextraction: A new method for sampling methamphetamine vapour.

Clandestine laboratories pose a serious health risk to first responders, investigators, decontamination companies, and the public who may be inadvertently exposed to methamphetamine and other chemicals used in its manufacture. Therefore there is an urgent need for reliable methods to detect and measure methamphetamine at such sites. The most common method for determining methamphetamine contamination at former clandestine laboratory sites is selected surface wipe sampling, followed by analysis with gas chromatography-mass spectrometry (GC-MS).

Physicochemical studies on the copper(II) binding by glycated collagen telopeptides.

Emerging evidence indicates that levels of advanced glycation end-products (AGEs) correlate with age- and diabetes-related organ damage and may play a causative role in such damage. Increased chelation of Cu(II) ions appears to play an important role in this process, however, the precise relationship between formation of AGEs and accumulation of Cu(II) is yet to be determined. The interaction between AGEs and Cu(II) has been investigated using a collagenous peptide that has been site-specifically modified by a key AGE.

Monitoring of degradation of porous silicon photonic crystals using digital photography.

We report the monitoring of porous silicon (pSi) degradation in aqueous solutions using a consumer-grade digital camera. To facilitate optical monitoring, the pSi samples were prepared as one-dimensional photonic crystals (rugate filters) by electrochemical etching of highly doped p-type Si wafers using a periodic etch waveform. Two pSi formulations, representing chemistries relevant for self-reporting drug delivery applications, were tested: freshly etched pSi (fpSi) and fpSi coated with the biodegradable polymer chitosan (pSi-ch).

Thermally modulated porous silica multispectral filters and their application in remote imaging.

We report a thermally tunable multispectral imaging filter based on reversible condensation of volatile organic fluids within a nanoporous one-dimensional photonic crystal. The photonic crystal (optical rugate filter) comprises oxidized porous silicon, prepared by electrochemical etch of silicon and subsequent air oxidation (porous silica rugate filter, pSiF). The reflectance spectrum of the pSiF is designed and constructed to match two of the red emission bands of the luminescent complex europium(III) tris-dipicolinate, [Eu(dpa)3](3-), which has been used as an indicator for anthrax spores.

Ionic strength effects on silicic acid (H4SiO4) sorption and oligomerization on an iron oxide surface: an interesting interplay between electrostatic and chemical forces.

The effect of ionic strength on reactions at aqueous interfaces can provide insights into the nature of the chemistry involved. The adsorption of H(4)SiO(4) on iron oxides at low surface silicate concentration (Γ(Si)) forms monomeric silicate complexes with Fe-O-Si linkages, but as Γ(Si) increases silicate oligomers with Si-O-Si linkages become increasingly prevalent. In this paper, the effect of ionic strength (I) on both Γ(Si) and the extent of silicate oligomerization on the ferrihydrite surface is determined at pH 4, 7, and 10, where the surface is, respectively, positive, nearly neutral, and negatively charged.

Preparation and characterization of pore-wall modification gradients generated on porous silicon photonic crystals using diazonium salts.

One-dimensional photonic crystals (rugate filters) constructed from porous silicon were modified by the chemical hydrosilylation of terminal alkenes (decyl, 10-carboxydecyl, and 10-hydroxydecyl) in the presence of a concentration gradient of diazonium salt initiators. The concentration gradient was generated by vertically orienting the Si wafer containing the porous Si layer in an alkene solution and then introducing the diazonium salt at the bottom edge of the wafer. Slow diffusion of the salt led to a varying density of grafted alkene across the surface of the porous layer.

Insights into H(4)SiO(4) surface chemistry on ferrihydrite suspensions from ATR-IR, Diffuse Layer Modeling and the adsorption enhancing effects of carbonate.

Silicic acid (H(4)SiO(4)) adsorbs at the ferrihydrite-water interface as monomeric or oligomeric surface silicate complexes.ATR-IR spectra were used to determine the proportions of monomeric and oligomeric surface silicate as a function of pH and Si surface concentrations (Γ(Si)) for H(4)SiO(4) in ferrihydrite suspensions.At each pH the proportion of adsorbed silicate present as monomers decreased as Γ(Si) increased while at a given Γ(Si) the proportion of adsorbed silicate present as monomers was higher at higher pH.

Electrochemical preparation of pore wall modification gradients across thin porous silicon layers.

Thin film porous silicon layers have been constructed in which the level of chemical modification to the pore walls is altered in a controlled gradient across the material. The gradient modification within such a nanoporous material represents a significant advance over gradients imposed across a flat surface. Gradients of methyl, pentyl acetate, and decyl groups are formed via electrochemical attachment of organohalides with an asymmetric electrode arrangement.

Recoveries of trace pseudoephedrine and methamphetamine residues from impermeable household surfaces: implications for sampling methods used during remediation of clandestine methamphetamine laboratories.

Evaluation of the risk posed by contaminants present during and after decontamination of clandestine methamphetamine laboratories requires a connection between the levels of contaminants measured and those actually present at the scene. The recoveries of pseudoephedrine and methamphetamine from glass, stainless steel, and a range of impermeable surfaces likely to be found in a clandestine laboratory were examined, using GC-MS of derivatized samples as the analytical method. When surfaces had been cleaned prior to drug deposition, wiping with water-dampened filter paper can recover 60-80% of pseudoephedrine immediately after deposition, and at least 50% of the pseudoephedrine still present on a surface after 2 days when deposited at a surface concentration of 2.

Silicic acid adsorption and oligomerization at the ferrihydrite-water interface: interpretation of ATR-IR spectra based on a model surface structure.

Oxide surfaces can promote specific lateral interactions between adsorbed species that become concentrated in specific orientations at an interface. In this article, in situ attenuated total reflectance (ATR) IR spectra were collected over time (from 0 to approximately 100 h) as the iron oxide ferrihydrite reacted with H(4)SiO(4) (between 0.007 and 1.

Compositional data analysis for elemental data in forensic science.

Discrimination of material based on elemental composition was achieved within a compositional data (CoDa) analysis framework in a form appropriate for use in forensic science. The methods were carried out on example data from New Zealand nephrite. We have achieved good separation of the in situ outcrops of nephrite from within a well-defined area.

Multiplexed DNA detection using spectrally encoded porous SiO2 photonic crystal particles.

A particle-based multiplexed DNA assay based on encoded porous SiO(2) photonic crystal disks is demonstrated. A "spectral barcode" is generated by electrochemical etch of a single-crystal silicon wafer using a programmed current-time waveform. A lithographic procedure is used to isolate cylindrical microparticles 25 microm in diameter and 10 microm thick, which are then oxidized, modified with a silane linker, and conjugated to various amino-functionalized oligonucleotide probes via cyanuric chloride.

Formation of Trifluoroacetylated Ephedrine During the Analysis of a Pseudoephedrine-Formaldehyde Adduct by TFAA Derivatization Followed by GC-MS.

(+)-Pseudoephedrine reacts with formaldehyde to form (4S,5S)-3,4-dimethyl-5-phenyloxazolidine. Gas chromatography-mass spectrometry (GC-MS) analysis after the reaction of this oxazolidine with excess trifluoroacetic acid anhydride (TFAA) shows predominantly N,O-bis(trifluoroacetyl)pseudoephedrine with some of the monotrifluoroacetylated derivative. In addition, variable amounts of N,O-bis(trifluoroacetyl)ephedrine were detected by GC-MS.

The inhibition by amines and amino acids of bleach-induced luminol chemiluminescence during forensic screening for blood.

Sprays containing alkaline solutions of peroxide and luminol are used as presumptive screens for bloodstains at crime scenes. These sprays can be subject to interference from hypochlorite-based cleaning agents (bleaches), leading to false positive results. This paper reports the screening of amines for their ability to decrease the interference by bleach while not greatly affecting the reaction with blood.