High-performance liquid chromatography filters

Hydrazine in air Lab method using sampling either onto acid-coated glass-fibre filters followed by solvent desorption or into specially constructed impingers. Linal analysis by derivatization and high performance liquid chromatography 86... 

Commercial grades of PVP, K-15, K-30, K-90, and K-120 and the quaternized copolymer of vinylpyrrolidone and dimthylaminoethylmethacrylate (poly-VP/ DMAEMA) made by International Specialty Products (ISP) were used in this study. PEO standard calibration kits were purchased from Polymer Laboratories Ltd. (PL), American Polymer Standards Corporation (APSC), Polymer Standards Service (PSS), and Tosoh Corporation (TSK). In addition, two narrow NIST standards, 1923 and 1924, were used to evaluate commercial PEO standards. Deionized, filtered water, and high-performance liquid chromatography grade methanol purchased from Aldrich or Fischer Scientific were used in this study. Lithium nitrate (LiN03) from Aldrich was the salt added to the mobile phases to control for polyelectrolyte effects. 

Soekhoe, U. and Kerstens, H.J. (1995) Determination ofPropoxur, Methiocarb, and Tinopal on Gloves, Filters, and Leaves by High Performance Liquid Chromatography, Report DATV/BT/076, TNO Nutrition and Food Research Institute, Department of Occupational Toxicology, Rijswijk, The Netherlands (in Dutch). 

Another important issue to take into account is the low solubility of many of the UV filters, which makes totally necessary to work with unit samples due to the indispensable solubilization step before the analytical determination by high performance liquid chromatography (HPLC). 

For high-performance liquid chromatography (HPLC) analysis samples (0.5 mL) were clarified by centrifugation at 14000 Gav for 5 min and the supernatant was decanted, filtered through a 0.2 yim in-line syringe filter and analysed directly by chiral HPLC (see below). 

V-Nitrosodiethanolamine can be determined in air and bulk process samples. Air samples are collected on glass fibre filters, extracted with 2-propanol and analysed by gas chromatography with thermal energy analyser detection. The limit of detection is 200 ng per sample (0.42 pg/m ). Bulk samples can be screened for 7V-nitrosodiethanol-amine by high-performance liquid chromatography (HPLC) with ultraviolet detection (Occupational Safety and Health Administration, 1990). 

ECD = electron capture detector GC = gas chromatography GFF = glass fiber filter(s) HPLC = high performance liquid chromatography MS = mass spectrometry NIOSH = National Institute of Occupational Safety and Health nitro reagent = A/-4-nitrobenzyl-A/-/ -propylamine UV = ultraviolet... 

A method for the determination of personal exposure to benzidine-based dyes has been developed. This procedure involved the reduction of benzidine-based dye filter samples to free benzidine with neutral buffered sodium hydrosulfite solution. The benzidine-containing reduction solution was then analyzed by high performance liquid chromatography. The reduction was found to be quantitative by visible-spectrum analysis. This reduction and analysis method was evaluated with four benzidine-based dyes over the range from 12 to 300 micrograms per sample. Precision for the reduction and analysis of the four dyes falls within % coefficient of variation. This method can differentiate between benzidine-and benzidine congener-based dyes. Results are reported in terms of free benzidine. 

Ion chromatography high-performance liquid chromatography (HPLC) is the method of choice for the quantification of oxalate, glycolate, and glycerate [3,4]. In addition, preservation and storage of the liquid samples may influence the stability of oxalate and glycolate. Use of urinary filter spots is a practical alternative approach for the collection and safe transport of samples to be analyzed for many metabolic disorders [5]. 

J,m poly(tetrafluoroethylene) (PTFE) syringe-tip filters High-performance liquid chromatography (HPLC) system equipped with Quaternary pump Diode array detector Vacuum degasser... 

An aldehyde was mixed with solid supported triphenylphosphine oxide (3 equiv.), alkyl halide (4 equiv.), and potassium carbonate (4 equiv.) in methanol (2 ml). The mixture was heated at 150° for 5 min. The residue was filtered through a short plug of silica gel and washed. The solution was concentrated and purified by reverse-phase high-performance liquid chromatography (RP-HPLC). 

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