High performance liquid chromatography determination of 4‐nonylphenol, 4‐tert‐octylphenol, and their short ethoxyl chain polyethoxylates in water samples using a microporous membrane liquid‐liquid extraction sample pretreatment technique

Abstract

High performance liquid chromatography determination of 4-nonylphenol, 4-tert-octylphenol, and their short ethoxyl chain polyethoxylates in water samples using a microporous membrane liquid-liquid extraction sample pretreatment technique Microporous membrane liquid-liquid extraction (MMLLE) sample pretreatment, coupled with reversed-phase high performance liquid chromatography with fluorescence detection (HPLC-FLD) was proposed for the determination of alkylphenols (APs), including 4-nonylphenol (4-NP) and 4-tert-octylphenol (4-t-OP), and their short ethoxyl chain polyethoxylates (SEC-APEOs) in environmental aqueous samples. After MMLLE, 4-NP, 4-t-OP, and SEC-APEOs were trapped in hexane used as acceptor. The hexane with enriched analytes was purged to dryness with nitrogen gas. Methanol (0.6 mL) and then water (1.4 mL) were added to dissolve the residue and the analytes were subsequently focused onto a C 18 precolumn prior to injection onto the analytical column for separation and detection by reversed-phase HPLC-FLD. The proposed procedure permits convenient determination of APs and SEC-APEOs, which have similar endocrine activity and appear as a single peak in reversed-phase HPLC. The detection limits for 4-NP and 4-t-OP were 0.1 and 0.05 lg/L, respectively. Four samples including tap water, river water, and effluent from a sewage treatment works water were analyzed by the proposed method and the recoveries at 0.5 lg/L spiked level were in the range of 74 -110%.

Preliminary study of the retention behavior for different compounds using cryogenic chromatography at different initial temperatures

“…Thermoelectric modules were made of an array of semiconductor couples connected electrically in series and thermally in parallel. Further details of the system were given on our earlier publications [13,14].…”

On-line membrane preconcentration for continuous monitoring of trace pharmaceuticals

“…HPLC coupled with integrated analyte extraction of antibiotics in sputum samples has been reported [4]. Inline LLE and SPE across a membrane along with HPLC detection has been used to determine trace levels of biocides in contaminated soil and water [5,6]. On-line procedures for analytical determinations of biological and environmental samples utilizing GC, MS and LC-MS have been successful [7,8].…”

Caracterização microbiana da remoção e degradação de 4-Nonilfenol em Reator Anaeróbio de Leito Fluidificado em escala aumentada >i<

“…Para a imobilização da biomassa no RALF utilizou-se areia como material suporte, devido aos bons resultados obtidos por Oliveira et al (2010) LIU et al, 2003;CRUCERU et al, 2012).…”

“…Para tanto, foi desenvolvido o método cromatográfico de quantificação de NF no Laboratório de Processos Biológicos (LPB-EESC-USP), utilizando parâmetros já relatados em literatura a fim de balizar a confecção dessa ferramenta analítica (LIU et al, 2003; BARAHONA; TURIEL; MARTÍN-ESTEBAN, 2011; CRUCERU et al, 2012).…”

“…Os testes em HPLC para o desenvolvimento do método analítico foram iniciados usando solução de 1000 μg L -1 de 4-NF solubilizado em metanol, coluna C-8 como fase estacionária e acetonitrila/água como fase móvel na proporção 90:10 (v/v). Para o detector de fluorescência 2 usou-se os comprimentos de onda (λ) de 220 nm (excitação 3 ) e 315 nm (emissão), conforme já relatado por Liu et al (2003) e Cruceru et al (2012). Esta primeira tentativa teve por objetivo obter a detecção do composto de interesse em uma matriz simples, sem demais contaminantes.…”