Leco

One of the important challenges facing hydrocarbon analysts is the accurate determination of the amounts of different classes of compounds in complex samples.

The objective of the study presented here is to develop a suite of toxicity markers from GC-TOFMS analysis, for use in pre-clinical screening of drug candidates.

Metabolomics and its toolset provide a foundation for quantitative biology and are indispensible for the detection of small molecules produced and/or transformed in the cells of living organisms.

Endocrine-disrupting compounds (EDCs) encompass a variety of chemical classes, including drugs, pesticides, polymer additives, coatings materials, personal consumer products, industrial by-products, and pollutants. There is worldwide concern over long-term environmental exposure to EDCs leading to serious health effects, including a range of reproductive problems such as reduced fertility, male and female reproductive abnormalities, skewed male/female sex ratios, brain and behavior problems, impaired immune functions, and various cancers.

The "Statistical Compare" option available in ChromaTOF software allows the user to view statistical comparisons as a data processing step for groups of samples. The groups of samples are divided into different subsets or classes. ChromaTOF software aligns the data for the specified group of samples from the data processed peak tables. Upon completion of peak alignment, statistical information (such as minimum, maximum, average, relative standard deviation, etc.) on various peak properties (such as peak height, peak area, retention time, etc.) can be viewed in the Compound Table generated by Statistical Compare. The software will also compare statistical information from each class and between classes. Additionally, "Fisher Ratios" can be calculated from the Compound Table for each analyte. The Fisher ratio is a statistical calculation that can be used to discover the unknown chemical differences among known classes of complex samples. Statistical Compare results can also be exported as a .csv file and applied to third party software programs for supplemental data reduction such asmultivariate analysis.

Citrus oils are widely used in consumer products. Contamination with pesticides is of particular concern because the citrus oils are derived from the outer portion of the fruit. GCxGC-TOFMS provides for analysis for many pesticides in citrus oils with minimal sample preparation. This work shows the ability of this technique to sufficiently separate these pesticides from the citrus oil components, to provide confirmation of identity, and to quantify these residues over several orders of magnitude concentration, reaching as low as part-per-billion levels.

Fragrances are complex mixtures that are part of everyday life. From cosmetics to household products, chemicals that produce scent are present at various levels, but little is known about their composition since fragrance formulas are considered trade secrets. New health concerns about allergic reactions caused by chemicals present in fragrances of synthetic or natural origin (it is estimated that 1 to 2% of the population has allergies to fragrance) have led to an increased interest in the analysis of perfumes. The 7th Amendment of the EuropeanCosmetics Directive requires the declaration of the listed 26 "fragrance allergens" (24 defined volatile substances and 2 botanicals) if they exceed specified levels. As a result, a project was initiated at the end of 2001 within the International Fragrance Association (IFRA) to develop a method for the analysis of "fragrance allergens", with the purpose of defining a way to determine and regulate their presence.

Endocrine-disrupting compounds (EDCs) encompass a variety of chemical classes, including drugs, pesticides, polymer additives, coatings materials, personal consumer products, industrial by-products, and pollutants. There is worldwide concern over long-term environmental exposure to EDCs leading to serious health effects, including a range of reproductive problems such as reduced fertility, male and female reproductive abnormalities, skewed male/female sex ratios, brain and behavior problems, impaired immune functions, and various cancers.

The complex nature of crude oil demands analytical solutions and instrumental methods that will separate and identify the complex chemical profile as well as characterize key chemical functional group class differences between complex samples. Comprehensive two-dimensional gas chromatography (GCxGC) expands the peak capacity of the chromatographic separation thereby increasing resolution and analyte characterization for complicated samples. Time-of-Flight mass spectrometry (TOFMS) offers continuous full range non-skewed mass spectral information and fast acquisition rates ideal for analyte identification of complex mixtures.