Two concentration methods for fast and routine determination of caffeine (using HPLC-UV detection) in surface, and wastewater are evaluated. Both methods are based on solid-phase extraction (SPE) concentration with octadecyl silica sorbents. A common “offline” SPE procedure shows that quantitative recovery of caffeine is obtained with 2mL of an elution mixture solvent methanolwater containing a...

It is a common practice to extract steroids from plasma, serum, or tissue samples prior to steroid measurement by radioimmunoassay (RIA) or enzyme immunoassay (EIA). Steroid extraction is critical because it can remove substances that interfere with the RIA or EIA. Steroid extraction is commonly achieved using organic solvents, such as diethyl ether or dichloromethane. However, organic solvent ...

BACKGROUND Quantification of 5-hydroxyindole-3-acetic acid (5-HIAA) in urine is useful in diagnosing and monitoring of patients with carcinoid tumors and in the study of serotonin (5-hydroxytryptamine) metabolism in various disorders. We describe an automated method that incorporates on-line solid-phase extraction (SPE) and HPLC to measure urinary 5-HIAA. METHODS Automated prepurification of ...

Steam distillation is used to isolate scent of rose flowers. Rose aromatic water is commonly used in European cuisine and aromatherapy besides its use in cosmetic industry for its lovely scent. In this study, three different sampling techniques, liquid-liquid extraction (LLE), headspace technique (HS), and solid phase extraction (SPE), were compared for the analysis of volatile water-soluble co...

pesticides are one of the major pollutants in the environment. the residue of pesticides has been reported to be at a critical level in agricultural crops, especially in greenhouse crops. tomato is considered as an important vegetable in iranian food basket and is produced in fields and greenhouses. so, the current study aimed to assess diazinon and oxydemeton-methyl levels in tomatoes sampled ...

a simple ion imprinted amino-functionalized sorbent was synthesized by coupling activated carbon with iminodiacetic acid, a functional compound for metal chelating, through cyanoric chloride spacer. the resulting sorbent has been characterized using fourier transform infrared spectroscopy (ft-ir), elemental analysis, thermogravimetric analysis (tga) and evaluated for the preconcentration and de...

The review of the RP HPLC analysis of basic psychotropic drugs is presented. It contains sample preparation methods with centrifugation, protein precipitation, liquid-liquid extraction (LLE), dispersive liquid-liquid microextraction (DLLME), solid-phase extraction (SPE), solid-phase microextraction (SPME), microwave-assisted extraction (MAE) and RP-HPLC analysis. Chromatographic behavior of bas...

The application of carbon nanotubes (CNT’s) for solid phase extraction (SPE) is still capturing the creative minds of the analytical chemists. This resulted in development of many modified procedures for difficult samples with improved analytical figures of merit. This review covers the most recent uses of CNT’s for SPE (up to December 31, 2009) that has not been covered in previous reviews. It...

Triphenylamine (TPA)-functionalized magnetic microspheres (Fe(3)O(4)/SiO(2)/TPA) were prepared and applied as solid phase extraction (SPE) adsorbents for the analysis of polycyclic aromatic hydrocarbons (PAHs) in environmental samples in combination with high-performance liquid chromatography (HPLC). The magnetic solid-phase extraction (MSPE) conditions affecting the extraction efficiency were ...