May 2012 Subscribe Go to Application Note Library PCDD/F Screening at the Maximum Residue Level for Food Safety Analysis Using Highly Selective Triple Quadrupole GC–MS-MS Dirk Krumwiede and Hans-Joachim Huebschmann, Thermo Fisher Scientific Following the US Environmental Protection Agency (US EPA) Method 1613A, this application presents a trace level screening procedure for PCDD/Fs and PCBs at the relevant maximum residue level for foodstuff.  The described MRM method uses selected MS-MS transitions for polychlorinated dioxins, furans, and PCBs from two different precursor ions and can detect individual product ions for each chlorination degree.   Analysis of Petroleum Hydrocarbons Standard for Underground Storage Tank Monitoring on a Thermo Scientific Ultrafast Column Bob Wiedemer, Thermo Fisher Scientific Underground storage tanks (UST) that are used to store various petroleum-based substances such as gasoline, diesel fuel, and fuel oil are monitored for leaks as authorized by the Resource Conservation and Recovery Act (RCRA). Gas chromatography is used for the analysis of these samples, which often have a wide range of molecular weights.   Multiresidue Analysis of Pesticides in Green Tea with Headspace SPME and the Thermo Scientific TSQ Quantum XLS David Steiniger, Eric Phillips, and James Chang, Thermo Fisher Scientific Food laboratories are being asked to meet lower detections over a wider range of compounds and matrices. Governmental regulating agencies are adding more compounds and lowering the MRLs for those already in existence. A key factor in improving sample throughput and providing robust analysis begins with the sample extraction and concentration.   GC–MS Analysis of Diethylene Glycol and Ethylene Glycol in Toothpaste Using Thermo Scientific TraceGOLD GC Column with SafeGuard Anila I. Khan, Thermo Fisher Scientific This application note demonstrates the semi-quantitative analysis of diethylene glycol (DEG) and ethylene glycol (EG) according to the FDA method at levels of 0.5 mg/g in toothpaste. Two approaches have been used to determine DEG and EG in toothpaste at a low level of 0.1 mg/mL in a full scan mode: 1. Thermo Scientific TraceGOLD TG-WaxMS GC column with 5-m SafeGuard, and a continuous 30-m phased analytical column with an integrated guard column, which is unphased; and 2. Thermo Scientific TraceGOLD™ Guard column attached to the analytical column via a press-fit. The FDA method is evaluated using both column formats and compared for the suitability of semi-quantitation of DEG and EG in toothpaste.   Analysis of Ethylene Carbonate and Ethyl Methyl Carbonate by GC-FID on a Thermo Scientific TraceGOLD TG-35MS Column Bob Wiedemer, Thermo Fisher Scientific Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) are used as electrolytes in lithium-ion batteries. As such, the quantitative analysis of these compounds is important to battery manufacturers. Reproducible peak areas and excellent peak shape for EC and EMC across multiple chromatographic runs were obtained on a TraceGOLD™ TG-35MS capillary GC column, an intermediate polarity 35% diphenyl/65% dimethyl polysiloxane phase.   Rapid Analysis of 303 Pesticide Residues in Green Bean Using Triple Quadrupole GC–MS-MS Chen Shubing, Yu Xuejun, Ningbo CIQ, Zhejiang, China, Ye Fangting, and Lu Ling, Thermo Fisher Scientific As the number of pesticides increases and maximum residue levels (MRLs) decrease in regulations, these techniques require that one sample be analyzed using several injections with different methods to screen for hundreds of pesticides. This application highlights the use of timed-SRM to screen and quantitate 303 pesticides in a single injection and highlights a convenient sample preparation procedure.   Comparison of WCOT and PLOT Columns for the GC–MS Analysis of Benzene in Soft Drinks A Khan, S. Aspey, and Luisa Pereira, Thermo Fisher Scientific The FDA method for the quantitation of benzene in soft drinks allows for the use of two approaches: 1. A capillary 6% cyanopropylphenyl polysiloxane (polar) wall coated open tubular (WCOT) column with cryogenic trapping; 2. A porous layer open tubular (PLOT) column fitted with headspace sampling. We have evaluated the Thermo Scientific equivalent columns specified in the FDA method and compared these for their suitability in the quantification of benzene at low concentrations.   Identification of Bath Salts by SPE and GC–MS Scott Adams and Kate Evans, Thermo Fisher Scientific This application note demonstrates a GC–MS method for identifying two compounds commonly found in “bath salts”. An extraction procedure for these compounds was optimized on a Thermo Scientific Servo+ Total B SPE cartridge. A readily available bath salt was analyzed by GC–MS using a Thermo Scientific TraceGOLD TG-5MS column and the active compound along with concentration was determined.