02 March 2009
By:Kenneth Lynam
Contract laboratory programme (CLP) pesticide analysis is demonstrated using a high-efficiency GC column (20 m × 0.18 mm i.d. × 0.18 μm film thickness) with helium carrier gas. An Agilent J&W DB-17ms column is used for primary analysis and DB-XLB column for confirmation. Primary analysis and confirmation of 22 CLP pesticides in the protocol is achieved in an 11 minute analysis, a 35% reduction in analysis time versus 0.32 mm i.d. columns.
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02 March 2009
Perflourinated organic acids are ubiquitous and found at relatively low concentrations in the environment.
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02 December 2008
Triple stage quadrupole LC–MS systems are often used for highly sensitive quantitative analyses of environmental pollutants. The performance of an LC–MS system is one important factor that determines if it will efficiently and accurately detect pollutants present at low concentrations in environmental samples. Another factor is the process by which the system pre-treats the samples. Thermo Scientific EQuan is an on-line LC–MS sample extraction and analysis system for environmental and drinking water analysis.
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02 December 2008
By:Kenneth Lynam
Polybrominated diphenyl ether (PBDE) analyses are important tools for understanding food supply and environmental quality worldwide. In this application, trace-level PBDE analysis is demonstrated using electron impact GC–MS. For these challenging separations, knowing that each GC column has been thoroughly tested for column inertness gives the analyst higher confidence in the accuracy of the results.
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02 December 2008
By:Philip L. Wylie
Pesticide residue analysis is a complex task because the analyst often has to search for hundreds of compounds in a wide variety of matrices. As required detection limits fall to 10 μg/kg (10 ppb) or lower for many pesticides, more sophisticated analytical tools are required. Matrices such as food, soil and even water can be very complex and one risks removing some target analytes if samples undergo too much clean-up.
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02 December 2008
By:Kenneth Lynam
Trace-and ultra trace-level polycyclic aromatic hydrocarbon (PAH) analyses are important tools for accessing environmental quality and foodstuff purity worldwide. In this application, trace-level PAH analyses are demonstrated using electron impact single quadrupole scanning mass spectrometry. In these challenging separations, knowing that the GC column has been thoroughly investigated for column inertness gives the analyst higher confidence in the accuracy of the results.
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02 July 2008
By:L.H. Reyes, G.M. Mizanur Rahman, T. Fahrenholz, L. Tucker
Mercury pollution mainly originates from industrial activities such as chlorine production, rubbish incineration and above all coal-fuelled power generation. The US Environmental Protection Agency (US EPA) considers mercury as highly toxic with a pronounced accumulative and persistent character. Here, several extraction techniques that are used for mercury speciation in biological samples by applying external calibration analysis and speciated isotope dilution mass spectrometry (SIDMS) are evaluated.
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02 July 2008
By:Kenneth Lynam
Semivolatile analyses using methods similar to US EPA method 82701 are important in environmental laboratories worldwide. A number of acidic compounds such as benzoic acid or 2,4-dinitrophenol and strong bases such as pyridine or benzidine are active species found in the semivolatile sample set. These highly polar species are particularly susceptible to adsorption into active surfaces in the sample flow path, including the column itself. System and column inertness are critical for effective analysis of these active chemical species.
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