Environmental Soil and Ground Water Assessment Using High Resolution Passive Soil-Gas Samplers - Petrex Method: Methodology and Results of a Case Study Performed in Brazil

1994 ◽  
Vol 29 (8) ◽  
pp. 161-172 ◽  
Author(s):  
D. C. Gomes ◽  
M. Alarsa ◽  
M. C. Salvador ◽  
C. Kupferschmid
Keyword(s):  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Cost Effective ◽  
Site Investigation ◽  
Soil Gas ◽  
Environmental Evaluation ◽  
Direct Sampling ◽  
Selection Of

The PETREX Passive Soil Gas Technique - applied successfully to environmental projects for 10 years - is the ideal primary investigative tool for soil and groundwater contaminations, since it is rapid, easy to apply and covers large areas. It is more sensitive and cost effective than other methods (e.g. active soil gas techniques). Passive collectors combined with high-resolution mass spectrometry permit direct mid reliable identification of over 9,000 volatile (VOCs) and semi-volatile organic compounds (SVOCs). PETREX is capable of providing comprehensive problem delineation during the initial stages of the site investigation, allowing for greater cost effectiveness in the planning of remediation programs and in the selection of appropriate monitoring well locations and other methodologies which may be needed to complete the environmental evaluation. PETREX therefore finds wide use in the investigation of contaminants, in the determination of pollution sources, as well as in audits connected to real estate transactions. This paper describes a case-study developed in Brazil, showing PETREX's usefulness and its correlation with soil and groundwater contamination plumes established from traditional direct sampling methods.

Determination of quaternary ammonium compounds in food products by the method of ultra-performance liquid chromatography/high resolution mass-spectrometry

2020 ◽  
Vol 86 (8) ◽  
pp. 23-31
Author(s):  
V. G. Amelin ◽  
D. S. Bolshakov
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Quaternary Ammonium ◽  
High Resolution Mass Spectrometry ◽  
Food Products ◽  
Quaternary Ammonium Compounds ◽  
High Resolution Mass ◽  
Ammonium Compounds ◽  
Resolution Mass

The goal of the study is developing a methodology for determination of the residual amounts of quaternary ammonium compounds (QAC) in food products by UHPLC/high-resolution mass spectrometry after water-acetonitrile extraction of the determined components from the analyzed samples. The identification and determination of QAC was carried out on an «UltiMate 3000» ultra-high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a «maXis 4G» high-resolution quadrupole-time-of-flight mass spectrometric detector and an ion spray «ionBooster» source (Bruker Daltonics, Germany). Samples of milk, cheese (upper cortical layer), dumplings, pork, chicken skin and ground beef were used as working samples. Optimal conditions are specified for chromatographic separation of the mixture of five QAC, two of them being a mixture of homologues with a linear structure (including isomeric forms). The identification of QAC is carried out by the retention time, exact mass of the ions, and coincidence of the mSigma isotopic distribution. The limits for QAC detection are 0.1 – 0.5 ng/ml, the determination limits are 1 ng/ml for aqueous standard solutions. The determinable content of QAC in food products ranges within 1 – 100 ng/g. The results of analysis revealed the residual amount of QAC present in all samples, which confirms data of numerous sources of information about active use of QAC-based disinfectants in the meat and dairy industry. The correctness of the obtained results is verified by introduction of the additives in food products at a level of 10 ng/g for each QAC. The relative standard deviation of the analysis results does not exceed 0.18. The duration of the analysis is 30 – 40 min.

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