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Shang D.,Pacific Environmental Science Center | Kirkwood J.,Varian, Inc
Proceedings of the 33rd AMOP Technical Seminar on Environmental Contamination and Response | Year: 2010

Traditionally, oil fingerprinting procedures have been mainly based on Gas Chromatography tandem Mass Spectrometry (GC/MS) techniques and on the application of various diagnostic Polycyclic Aromatic Hydrocarbons (PAH) or biomarker ion ratios. This approach is rigorous and systematic, often producing conclusive results even from heavily weathered samples. However, there are some limitations of the GC/MS ion ratio methodology in differentiating engine lubricating oil and biodiesel samples. Often the same base oil is used to formulate the motor oil products; the current GC/MS method usually encounters difficulty in distinguishing different oil products from the same type of lubricating oils. For GC/MS biodiesel identification, either specialty GC column or time consuming chemical derivatization, fractioning and column clean-up are needed. Fourier transform infrared (FTIR) spectroscopy has been applied to chemical analysis in environmental applications, yet this powerful analytical technique is not currently in widespread use in forensic oil analysis. We report here a novel approach in forensic lube oil and biodiesel identification by applying both FTIR and GC/MS techniques simultaneously. The newly developed method is based on comparison of some characteristic infrared and GC/MS peaks of the lube oil and biodiesel from both environmental and source samples. Pattern recognition techniques are used in the oil identification, and advantageously, minimum sample preparation is needed for the method. The newly developed method is rapid, easy to use, and can be applied for many types of lube oils and biodiesel for the identification of the source of an oil spill. Source

Kuo J.-N.,Environment Canada | Buday C.,Pacific Environmental Science Center | Van Aggelen G.,Pacific Environmental Science Center | Ikonomou M.G.,Northwest Atlantic Fisheries Center | Pasternak J.,Environment Canada
Environmental Toxicology and Chemistry | Year: 2010

Emamectin benzoate is one of the active ingredients of the anti-sealice drug SLICE®. Ten-day acute sediment lethal tests (10-d LC50) of emamectin benzoate and its desmethyl metabolite (AB1) were conducted to determine LC50 values using a sensitive representative West Coast amphipod crustacean, Eohaustorius estuarius. The 10-d LC50s of emamectin benzoate and AB1 to E. estuarius were 0.185 and 0.019 mg/kg wet weight sediment (0.146 and 0.015 mg/kg dry wt), respectively. The degradation properties of emamectin benzoate and AB1 during the 10-d period were also measured and described. No obvious decay patterns were observed for either emamectin benzoate and AB1 over the 10-d period. © 2010 SETAC. Source

Parton J.,Pacific Environmental Science Center | Shang D.,Pacific Environmental Science Center
Proceedings of the 34th AMOP Technical Seminar on Environmental Contamination and Response | Year: 2011

Environmental chemical spills, whether accidental or intentional, require that immediate action be taken to ensure the safety of the public and to protect the environment; one of the first steps in this process is identification of the spilled chemical(s). Addressing the issue of chemical identification is one of the many responsibilities of the analysts at Environment Canada, who are continually developing and improving methods for rapid response to such emergencies. It is important that environmental testing laboratories be prepared for even the rare events in which so-called "white powder" chemical are spilled in the environment. Fourier transform infrared (FT-IR) spectroscopy is a common analytic tool used in this field of forensic chemistry; especially when rapid response is required. However, the analysis of such samples by traditional FT-IR requires either dissolution in a solvent or inclusion in a KBr pellet; both of which can be difficult and time consuming, and produce results that are difficult to reproduce. Attenuated Total Reflectance (ATR) FT-IR provides a simple and effective alternative for the identification of many powdery samples, and overcomes the aforementioned challenge. While the application of ATR FT-IR spectroscopy in the identification of pure powdery samples has become common practice, few attempts to apply ATR FT-IR in the identification of white powdery mixtures have been reported. We present here a novel, proof-of-concept approach to white powder binary mixture (WPBM) identification utilizing ATR FT-IR spectroscopy and Resolutions Pro software. A method was developed through the analysis of pure samples and binary mixtures of common white powders, using an "in-house" built spectral library of eighteen common white powders for sample identification. The method was successfully applied to a series of WPBMs, and was evaluated through the identification of three unknown white powder samples in a "blind test". ATR FT-IR is thus demonstrated as a potentially useful method for rapid qualitative identification of unknown white powder samples containing two components. Source

Shang D.,Pacific Environmental Science Center | Haberl M.,Pacific Environmental Science Center
Proceedings of the 34th AMOP Technical Seminar on Environmental Contamination and Response | Year: 2011

A chemical spill, whether accidental or intentional, usually requires immediate countermeasures to combat public anxiety and minimize any risk to the environment and society. In the case of spill or release of potentially toxic unknown chemicals, rapid identification is essential and is often the first step in addressing the situation. However, identification of unknown organic chemicals is a complex problem which usually requires detailed and specific analytical methods, as well as the experience and knowledge of an analyst specialized in chemical spills. The typical approach to this problem has been to "guess first, and then choose a test method". This approach sometimes works, but is time-consuming, empirical in nature, and can be "hit or miss" - even for experienced chemists. In fact, this traditional way is often impractical for less-experienced chemists. To address this situation, a comprehensive and systematic procedure for fast identification of unknown spilled organic chemicals was developed. The first step of this procedure is a "universal" sample processing method to extract organic compounds from various sample matrices, such as so-called "white" powders, soil, vegetation and surface water. Secondly, the extract is simultaneously analyzed by GC/MS and LC/MS using scan mode; the results are then searched, using NIST spectral library in the case of GC/MS, and an in-house built deleterious compounds spectral library for LC/MS. Finally samples are run, with GC/MS using Selected Ion Monitoring (SIM), and LC/MS/MS using Multiple Reaction Monitoring (MRM), to screen for a large number of the most common environmental pollutants from 10 to 1000 ppb. This rapid screening procedure can process and report results for up to 8 samples in one day by a single chemist. Three real world examples are presented to demonstrate the applicability of this procedure in dealing with chemical spills. This approach addresses the urgent need for comprehensive, systematic and documented procedure to provide scientific rigor, acceptable in chemical spill related legal cases. Source

Shang D.,Pacific Environmental Science Center | Kim M.,Agilent Technologies | Haberl M.,Pacific Environmental Science Center | Legzdins A.,Pacific Environmental Science Center
Journal of Chromatography A | Year: 2013

Over the past 20 years, oil sands exploration and processing in Canada have grown steadily, leading to the development of intensive large-scale operations in Alberta, Canada. Naphthenic acids (NAs), a complex mixture of aliphatic and alicyclic carboxylic acids, are by-products of oil sands processing and are known to be toxic. While oil sands processing water (OSPW) is contained in tailings ponds, potential seepage and leaking of OSPW and its contaminants into surrounding surface water systems is a concern. The ability to quantify NAs and their isomers in OSPW surrounding water is essential for monitoring these spills. Unfortunately, quantification of NAs and their isomers is challenging due to the complexity of the NA mixtures, the lack of commercially available standards, and interference from naturally occurring NA compounds. Techniques such as FT-IR and GC/MS are currently used to analyse NAs, but are limited by poor sensitivity and specificity in the case of FT-IR and long sample preparation and instrument run time for GC/MS. To tackle these issues, a rapid LC/MS method was developed which can quickly quantify NAs in surface water with much better sensitivity and specificity than current methods. This method uses large volume injection, ESI negative mode and a Poroshell LC column to improve the method limits of detection (LOD) and quantitation (LOQ). The method is robust and has no complicated sample preparation steps. The method detection limit (MDL) is 0.01. mg/L (10. ppb) and low limit of quantitation (LLOQ) of 0.1. mg/L (100. ppb), both for surface water. The developed method was tested with samples from the oil sands producing region, and demonstrated its applicability for fast screening of surface water samples before resorting to costly high accuracy and high resolution mass spectrometry determination. This is the first very rapid LC/MS method using large volume single column direct injection for quantitative determination of naphthenic acids in surface water. © 2013. Source

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