Gas Chromatography
Joseph Chamberlain in The Analysis of Drugs in Biological Fluids, 2018
The usefulness of the electron-capture detector is its responsiveness to certain types of compounds and its lack of response to even large amounts of other compounds. Thus, the modern electron-capture detector is extremely useful for analyzing drugs in both pharmaceutical preparations and in biological fluids. The most strongly electron capturing compounds are those containing halogens or nitro groups (Table 6.4), or extended conjugated systems, such as for the metabolite of spironolactone, canrenone.471 A popular general method for benzodiazepines is to convert the benzodiazepine to the corresponding benzophenone and determine the highly conjugated. halogenated product by electron-capture gas chromatography (Figure 6.5).526 Typically, the electron-capture detector would be expected to measure drugs at the low ng ml−1 level in biological fluids.
Pesticides and Chronic Diseases
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
Chlorinated pesticide levels in each patient's body were analyzed from adipose tissue. Sampling was formed at the time of diagnosis or immediately following completion of therapy. Using sterile technique, a left lower quandrant of abdominal incision 5 cm in length was made following injection of local anesthesia. A segment of adipose tissue measuring approximately 4 × 3 × 2 cm was resected and the wound was closed in two layers. The adipose tissue was placed in an amber bottle supplied by the toxicology laboratory, refrigerated, and then sent by overnight courier to Accu-Chem Laboratories in Richardson, Texas. Accu-Chem Laboratories was a CLIA, Cap, and Medicare certified full-service toxicology lab. A panel of 21 chlorinated pesticides (Table 7.1) was analyzed for each specimen of adipose tissue. The method of analysis was high-resolution gas chromatography/electron capture detector. In addition to the cancer patients, two normal controls (37-year-old white male, 40-year-old white female) with no past history of cancer, asthma, rhinitis, hypertension, vascular disease, or autoimmune disease were tested for pesticide residues. Both controls live in Grady County and both had a family history of cancer. Their levels are shown in Tables 7.2 and 7.3, with the averages shown in Table 7.4.
Analysis Update—Full Spectrum Cannabis
Betty Wedman-St Louis in Cannabis as Medicine, 2019
After the column separates the compounds, they pass through a detector, which does exactly what it states as it detects each compound. GC and LC utilize different types of detectors. For example, a GC can use a flame ionization detector (FID), thermal conductivity detector (TCD), electron capture detector (ECD), flame photometric detector (FPD), and a flame thermionic detector (FTD). If one were using a FID detector the technique would be referred to as GC/FID. A GC/FID system could be utilized for terpene analysis with the addition of a headspace autosampler. The headspace autosampler has two functions. The autosampler is an automated robot bringing the next sample in line to be analyzed. The headspace heats up the cannabis sample between 70°C and 275°C, so the volatile terpenes can be separated from most of the cannabis matrix, which contains over 500 compounds, allowing for easier separation in the column.
Veterinary utility of dried blood spots for analysis of toxic chlorinated hydrocarbons
Published in Toxicology Mechanisms and Methods, 2018
Andreas F. Lehner, Margaret Johnson, John Buchweitz
Analyses are performed on Varian (now part of Agilent Technologies, Santa Clara, CA) 3400 GCs each equipped with an electron capture detector (ECD). Both instruments are operated with helium carrier gas and nitrogen as ECD makeup gas. One instrument is equipped with a DB-1701 column (Agilent, Santa Clara, CA), and is referred to as 1701 GC in this paper; column dimensions are 15 m length × 0.32 mm ID with a 0.25 μm film thickness. The 1701 GC is run with the following temperature settings: (1) injector 250 °C; (2) detector 300 °C; (3) oven program: 150 °C initial, held for 0.5 min, then increasing at 5 °C/min to 280 °C final temperature, which is held for 15 min (total run time, 38 min). The second instrument is equipped with a DB-608 column (Agilent, Santa Clara, CA), and is referred to as 608 GC in this paper; column dimensions are 30 m length × 0.32 mm ID with a 0.5 μm film thickness. The 608 GC is run with the following temperature settings: (1) injector 250 °C; (2) detector 300 °C; (3) oven program: 150 °C initial, held for 0.5 min, then increasing at 12 °C/min to 280 °C final temperature, which is held for 20 min (total run time, 31.3 min). Both instruments are held in splitless mode during injection and from 0.01 to 0.8 min.
Evaluation of organochlorine pesticides in foodstuff of animal origin from middle governorates of Jordan in 2018 and 2019 using GC-ECD
Published in Toxin Reviews, 2021
Tawfiq M. Al-Antary, Mahmoud A. Alawi, Rana Keewan, Nizar A. Haddad
Bruker GC-456 was used in this study. It was equipped with two capillary columns and a 63Ni-Electron Capture Detector (ECD). The column 1 was a non-polar capillary HP-5 (30 m × 0.25 mm; 0.25 µm film thickness). Column 2 was a low/mid polar capillary DB-1701 (30 m × 0.32 mm; 0.2 µm film thickness). The carrier gas was helium with flow rate of 1.1 mL/min. The make-up gas flow rate was 25 mL/min. The injector temperature was 280 °C, and the detector temperature was 300 °C. Column temperature program was 150 °C for 5 min, 150–220 °C (13 °C/min) for 20 min, 220–250 °C (20 °C/min), and 250 °C for 10 min. Injection volume was 1 µL and the split ratio was 1:10 (Alawi et al.2015, AlAntary et al.2018).
Pesticides exposure through environment and risk of pre-term birth: a study from Agra city
Published in Drug and Chemical Toxicology, 2019
M. Anand, L. Singh, P. Agarwal, R. Saroj, A. Taneja
After extraction, the sample analysis was carried out at Advanced Instrumentation Research Facility (AIRF), Jawaharlal Nehru University, New Delhi on gas chromatograph equipped with Electron Capture Detector (ECD) under the standardized conditions. Comparing the peaks in tests with those of standards, enabled us to do quantification and tentative identification of pesticides. Further, these findings were confirmed with the help of results obtained from dual column gas chromatography/mass spectrometry (GC-MS).
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