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Abstract: The routine method of paper chromatography includes five steps: spotting, separating, drying, spraying/immersing and color development. In this paper, a pre-staining paper chromatography which only consisted of spotting, separating and color development was developed for quantitative analysis of γ-aminobutyric acid. Compared to the routine paper chromatography, the improved method is clean, rapid, inexpensive and reproducible. The effects of ninhydrin concentration, color temperature, color time and Cu2+ concentration on the color yield in the ninhydrin reaction were optimized. And then the pre-staining paper chromatography coupled with vis spectrophotometry was applied to γ-aminobutyric acid quantification. The results indicated that the limit of detection was 0.05mgmL−1 and the linear range was from 0.5 to 20.0mgmL−1. Furthermore, an excellent correlation coefficient was observed with an R 2 =0.998. The method is accurate (RSD<2.64%), and has good recoveries (102.7–103.9%). The validation of the modified technique was verified by a HPLC method. [Copyright &y& Elsevier]

Abstract: A simple and sensitive high performance liquid chromatographic (HPLC) method with UV detection was developed for the determination of new diethanolamine derivative complexing agents. The quantitation of three complexing agents was accomplished as their Cu(II) complexes and their separation on a reversed phase C18 column using 0.01M tetrabutyl ammoniumhydroxide and methanol as isocratic mobile phase. The limit of detection (LOD) ranges from 0.1 to 2.0mg/l and the method has a wide linear range, from LOD to 150mg/l. The method was successfully applied for the analysis of lake water and wastewater effluent from pulp and paper mill spiked with studied complexing agents. [Copyright &y& Elsevier]

Three analytical methods were developed for the determination of toxic compounds in recirculating waters of a paper-recycling industry. Three main groups of compounds were considered: (i) wood extractives originated from the raw material; (ii) biocides added during the production process and (iii) surfactants and other adjuvants present in the formulates of these biocides. Wood extractives considered in this study included fatty and resin acids. They were analysed by liquid–liquid extraction using methyl tert.-butyl ether, followed by gas chromatography–mass spectrometry for previous formation of the respective trimethylsilyl esters. Water samples were also extracted with Oasis HLB (copolymer [poly(divinylbenzene-co-N-vinylpyrrolidone]) solid-phase extraction cartridges of 60 mg and analysed by liquid chromatography–electrospray mass spectrometry for the determination of additives and biocides. Using these two approaches levels up to 15 mg/l for total resin and fatty acids, 5 mg/l for alkylbenzene sulfonates and 2-(thiocyanomethylthio)benzotiazol, 100 μg/l for bisphenol A and 2,2-dibromo-3-nitrilepropionamide, and 300 μg/l for nonylphenol ethoxycarboxylate were detected in process waters at different production treatment stages. These levels are of relevance since poor water quality affects the paper-recycling process, the primary water treatment process and eventually, the environmental water quality. [Copyright &y& Elsevier]

Abstract: The determination of perfluorooctanoate (PFO) in articles of commerce has become increasingly important to understand if treated products are a possible source of PFO. An LC–MS/MS method for the determination of PFO in paper and textile using a dual labeled 13C-PFOA internal standard was successfully developed and validated. Residues of PFO were determined using an isocratic, reversed-phase high-performance liquid chromatography (HPLC) method with an ammonium acetate/methanol buffer. Ions monitored were 413 (parent) and 369 (daughter) for PFO and 415 (parent) and 370 (daughter) for dual labeled 13C-PFOA internal standard. As a precaution against ubiquitous PFO that occasionally occurs in mobile phase or instrument components, two Hypercarb™ cartridges (4mm) were placed before the HPLC injector. Any PFO that was captured by the cartridges was removed before each injection by flushing the system with 100% methanol prior to equilibration with the isocratic mobile phase. Overall recovery and standard deviation over a 3 day validation regimen for samples (n =54–55) fortified with PFOA at 5, 50, and 200ngg−1 were 114±4.9% for textile and 110±7.6% for paper. The results also established a limit of detection (LOD) of 1ngg−1 in textile and 2ngg−1 in paper based upon S/N of the 5.0ngg−1 fortification versus the untreated paper and textile. [Copyright &y& Elsevier]

Abstract: A comprehensive method for the determination of four stilbene-type disulfonate and one distyrylbiphenyl-type fluorescent whitening agents (FWAs) in paper materials (napkin and paper tissue) and infant clothes was developed. FWAs were extracted from paper material and cloth samples using a hot-water extraction, and the aqueous extracts were then preconcentrated with the newly developed Oasis WAX (mixed-mode of weak anion exchange and reversed-phase sorbent) solid-phase extraction cartridge. The analytes were unequivocal determined by ion pair chromatography coupled with negative electrospray ionization-tandem mass spectrometry (HPLC-ESI–MS–MS), applying a di-n-hexyl-ammonium acetate (DHAA) as the ion-pairing reagent in mobile phase. Limits of quantitation (LOQ) were established between 0.2 and 0.9ng/g in 2g of samples. Recovery of five FWAs in spiked commercial samples was between 42 and 95% and RSD (n =3) ranging from 2 to 11%. The method was finally applied to commercial samples, showing that two stilbene-type disulfonates were predominant FWAs detected in napkin and infant cloth samples. [Copyright &y& Elsevier]