Environmental analysis steroids

The LC-MS analysis of steroids is discussed from a more general perspective in Ch. 13. In environmental analysis, SPE on C,8- or carbon-materials are generally applied for analyte extraction and preconcentration. Gradient elution using 20-100% acetonitrile in water on a Cig-colunm is used in combination with either negative-ion ESI or positive-ion APCI. 

UV/VIS spectrophotometry is a widely used spectroscopic technique. It has found use everywhere in the world for research, clinical analysis, industrial analysis, environmental analysis, and many other applications. Some typical applications of UV absorption spectroscopy include the determination of (1) the concentrations of phenol, nonionic surfactants, sulfate, sulfide, phosphates, fluoride, nitrate, a variety of metal ions, and other chemicals in drinking water in environmental testing (2) natural products, such as steroids or chlorophyll (3) dyesmff materials and (4) vitamins, proteins, DNA, and enzymes in biochemistry. 

The analysis of steroid sexual hormones and related synthetic compounds in WW, soil, sludge, and sediment samples is a challenging task. This is due to both the complex environmental matrices and the requirement of low detection limits. Therefore, the use of complicated, time- and labor-consuming analytical procedures is necessary. 

The ECD has seen its greatest utilization in the field of pesticide analysis. Chemicals such as dieldrin, aldrin and DDT are amenable to the ECD. In addition, the environmental hazards of polychlorinated biphenyls (PCBs) have been raised as a result of analyses by the ECD. Organometallics are also good electron absorbers. With the aid of halogen derivatization, many classes of organic compounds such as steroids, acids, amines, phenols, and alkenes have been assayed. 

Reversed-phase chromatography is the most popular mode for the separation of low molecular weight (<3000), neutral species that are soluble in water or other polar solvents. It is widely used in the pharmaceutical industry for separation of species such as steroids, vitamins, and /3-blockers. It is also used in other areas for example, in clinical laboratories for analysis of catecholamines, in the chemical industry for analysis of polymer additives, in the environmental arena for analysis of pesticides and herbicides, and in the food and beverage industry for analysis of carbohydrates, sweeteners, and food additives. 

Steroids hormones as environmental pollutants Analysis of steroids as environmental endocrine disrupting compounds sample preparation, e.g., LLE vs. SPE immunoassay vs. GC-MS/ MS and LC-MS/MS analyses sensitivities, e.g., LOD at pg-ng/mL level. [13]... 

SBSE can be successfully used in the analysis of environmental samples [93-97] and for food analysis [98, 99]. PDMS is the most commonly used polymer, primarily because of its thermal stability and durability. SBSE has been modified by application of derivatization with different reagents (acetic anhydride, BSTFA, etc) [100-104]. This approach is suitable for the extraction of compounds requiring derivatization. The use of multistep derivatization with several extraction elements (each reaction is performed on a different stir bar) allows efficient extraction, desorption, and chromatographic analysis of compounds with different functional groups (e.g., phenols, steroids, amines, thiazoles, ketones). Acetic anhydride (ester formation), ethyl chloroformate (reaction of acids and amines), tetraethyloborane, and sodium bis-trimethylotrifluoroacetamide have been used for extraction and simultaneous derivatization [105]. 

Kelly, C., Analysis of steroids in environmental water samples using solid-phase extraction and ion-trap gas chromatography-mass spectrometry and gas chromatography-tandem mass spectrometry, J. Chromatogr. A, 872, 309-314, 2000. 

GC-MS has been the technique most commonly implicated in the determination of estrogens in environmental samples. Both conventional MS and ion trap (IT)-MS detection have been accomplished in the El mode at 70 eV, usually in the selected ion monitoring (SIM) mode, and, in most cases, after sample derivat-ization, while the use of negative (N)CI has seldom been reported. The sensitivity of GC-MS-MS was reported to be in the range 20 pg pi (limit of quantification). A recent study has also discussed the possibilities of high-resolution (HR)MS for analysis of steroid sex hormones in environmental samples, showing that, with 20 000 resolution, lOpg of ethynyl estradiol can be detected. This amount corresponds to a detection limit of 1 ppt if the ethynyl estradiol is in 11 of water (concentrated into a 0.1 ml extract, followed by injection of 1 pi). 

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