Determination of pKa values of active pharmaceutical ingredients

Babić, Sandra; Horvat, Alka J.M.; Pavlović, Dragana Mutavdžić; Kaštelan‐Macan, Marija

doi:10.1016/j.trac.2007.09.004

Cited by 457 publications

(271 citation statements)

References 41 publications

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“…After mixing and aging for 24 h (Schlusener et al 2003), the soil samples were extracted with 15 mL of the mixture of acetonitrile and EDTA-McIlvaine buffer (pH 4.0) (2:1) in the presence of ultrasonic treatment, and then (Zorita et al 2009) b (Babić et al 2007) c (Feitosafelizzola and Chiron 2009) d (Park and Choi 2008) e (Sanderson and Thomsen 2009) f (Tolls 2001) g (Lutzhoft et al 1999) h (Diaz-Cruz et al 2006) i (Kan and Petz 2000) j (Jacobsen et al 2004) k l (Kim and Tanaka 2009) m (Calza et al 2009) n (Skinner and Kanfer 1992) p (Chee-Sanford et al 2009) q (Suárez et al 2008) Group Analytes Molecular weight…”

Section: Methodsmentioning

confidence: 99%

Occurrence and distribution of antibiotics in urban soil in Beijing and Shanghai, China

Gao

Shi

et al. 2015

Environ Sci Pollut Res

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The recycling of reclaimed wastewater for irrigation and road cleaning is an important strategy to minimize water scarcity in megacities. However, little is known regarding the potential accumulation of antibiotics contained in reclaimed wastewater in urban soil. We investigated the occurrence and distribution of eight quinolones (QNs), nine sulfonamides (SAs), and five macrolides (MLs) antibiotics in urban surface soil in Beijing and Shanghai, China. QNs, especially norfloxacin (NOR), ofloxacin (OFL), and ciprofloxacin (CIP) were the predominant antibiotics in urban surface soil, and NOR revealed the highest average concentration of 94.6 μg kg −1 . The antibiotic concentrations in urban soil in our study were higher than those detected in agricultural soils after long-term wastewater irrigation and manure fertilization. The concentrations of antibiotics in Shanghai urban soil showed a significant negative correlation with soil pH and a positive correlation with total organic carbon (TOC), reflecting the effect of speciation and soil organic matter content on sorption and retention. In addition, antibiotic concentrations in the urban soil were positively correlated with heavy metal contents, likely due to their coexistence in reclaimed wastewater and the promoting effect of metals on the sorption of antibiotics. In several soil samples, NOR, OFL, CIP, enrofloxacin (ENR), and fleroxacin (FLE) showed higher concentrations than the trigger value of 100 μg kg −1 in soil, indicating a potential risk for the environment.

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Section: Methodsmentioning

confidence: 99%

Occurrence and distribution of antibiotics in urban soil in Beijing and Shanghai, China

Gao

Shi

et al. 2015

Environ Sci Pollut Res

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“…Potentiometry [5] and UV-VIS absorption spectrometry [6] are useful techniques for the determination of pKa values, due to their accuracy and reproducibility. Nowadays, some methods for dissociation constants determination, based on separation methods [7], [8] including high performance liquid chromatography (HPLC), capillary electrophoresis (CE) are used.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Studies of Oxalic Acid Dissociation in Water-Ethanol Solvents

2015

IJSR

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Abstract:The first and second dissociation constants of oxalic acid were determined using potentiometric and spectrophotometric methods. Measurements were made in water-ethanol solvents of chemical composition in percentage weight of 0, 16.3, and 80. The temperatures ranged from 298K to 318K. The dissociation free enthalpy changes, enthalpy changes and entropy changes were determined and discussed. Furthermore, DFT was used at B3PW91/LanL2DZ level to compute molecular descriptors as E HOMO , E LUMO , energy gap and the charge on the oxygen of the hydroxyl group. Those parameters were then used to establish a QSPR model that furnishes pKa 1 and pKa 2 values. Experimental and theoretical results were in good agreement.

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“…Since the D OW of an ionizable compound is pH dependent, the pH independent partitioning coefficient of its neutral molecular form (K OW ) is generally reported in the literature. Though various methods have been developed for the determination of K OW [3] and pK a [4] values, alternatives for high efficient determination of these parameters are still of interests. New approaches by using magnetic nano-absorbent [5], and twophase hollow fiber-based liquid-phase microextraction procedures with 1-octanol filled in the lumen of a hollow fiber [6] or supported in the pores of hollow fiber membrane wall [7] were adopted for the measurement of D OW and K OW , whereas negligible depletion solid- * Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

Development of negligible depletion hollow fiber membrane-protected liquid-phase microextraction for simultaneous determination of partitioning coefficients and acid dissociation constants

Liu

Cai

et al. 2009

Journal of Chromatography A

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Determination of pKa values of active pharmaceutical ingredients

Cited by 457 publications

References 41 publications

Occurrence and distribution of antibiotics in urban soil in Beijing and Shanghai, China

Occurrence and distribution of antibiotics in urban soil in Beijing and Shanghai, China

Experimental and Theoretical Studies of Oxalic Acid Dissociation in Water-Ethanol Solvents

Development of negligible depletion hollow fiber membrane-protected liquid-phase microextraction for simultaneous determination of partitioning coefficients and acid dissociation constants

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