Simulation of nonylphenol degradation in leafy vegetables using a deuterated tracer

Abstract

In this study, the residues of nonylphenol, an endocrine-disrupting chemical, were investigated in two types of leafy vegetables, leek and cabbage, that are commonly consumed in eight provinces in China. Nonylphenol was detected in 43.50% of the 223 samples, at concentrations up to 51.90 μg kg(-1). The isotopic tracer 4-n-NP-2,3,5,6-d4-OD was chosen to simulate the degradation of nonylphenol in cabbage. More than 80% of the tracer was degraded in the first 7 days, and most of it had vanished by the end of the 35-day experimental period. A preliminary degradation equation was established to describe the variation of nonylphenol residues in leafy vegetables, and the amounts of nonylphenol in four pesticides were analyzed. The results indicated that nonylphenol residues in leafy vegetables are probably derived from the applied pesticides. The potential risk of pesticide adjuvants as well as that of the active ingredient in pesticides should be taken into consideration when recommending a safety interval period.

Occurrence, fate and toxic effects of the industrial endocrine disrupter, nonylphenol, on plants - A review

“…Previous studies reported the presence of NP on various fruits and vegetables in China, Germany, Taiwan and the USA (Fang et al, 2015;Guenther et al, 2002;Lu et al, 2007Lu et al, , 2013Dodgen et al, 2013;She et al, 2012) (Table 1). All of these fresh products were obtained from producers or supermarkets, except for those analysed by Dodgen et al (2013), where the presence of NP was as a consequence of fortified incubation in the laboratory.…”

“…Surfactants are also added to biocontrol products to enhance the effect of the biocontrol agent by contributing to adherence, spreading and enabling penetration (Singh et al, 2007). Following pesticide application, NP can still be detected on crops after 35 days (Fang et al, 2015).…”

“…Nonylphenol is becoming increasingly ubiquitous on vegetables and fruits (Fang et al, 2015). In fact, diet appears to be the major exposure route of NP to humans (USA Environmental Protection Agency, 2010).…”

“…In fact, diet appears to be the major exposure route of NP to humans (USA Environmental Protection Agency, 2010). Contamination of edible plants is generally via exposure to sludge-amended soil, polluted water, the use of cleaning agents in the food processing industry and application of wax coats and pesticides on crops (Fang et al, 2015;Lu et al, 2007;Soares et al, 2008). Food packaging material may also contain NP or tris (nonylphenol) phosphate (TNPP) that are used as plasticisers or antioxidants (Lu et al, 2007;Votavová et al, 2009).…”

“…The pre-treatment involves extra drying and extraction steps (Olujimi et al, 2010). Prior to extraction, the solid samples are dried and homogenised (Petrovic and Barceló, 2000) after which extraction is performed using steam distillation (Guenther et al, 2002), ultrasonication (Fang et al, 2015;Lu et al, 2015); solid phase (SPE) extraction (Fang et al, 2015); soxhlet extraction (Díaz-Cruz et al, 2003;Noppe et al, 2007;Ternes et al, 2002) or liquid-liquid extraction (Lu et al, 2007). The former uses methylene chloride (Lu et al, 2015) or mixtures of hexane and other solvents such as acetonitrile and isooctane (Guenther et al, 2002;Lu et al, 2007;Petrovic et al, 2002).…”