Effects of rice straw biochar on sorption and desorption of di-n-butyl phthalate in different soil particle-size fractions.

Sorption of organic contaminants by biochar greatly affects their bioavailability and fate in soils. Nevertheless, very little information is available regarding the effects of biochar on sorption and desorption of organic contaminants in different soil particle-size fractions. In this study, di-n-butyl phthalate (DBP), a prevalent organic contaminant in agricultural soils, was taken as a model contaminant.

Low-molecular-weight organic acids correlate with cultivar variation in ciprofloxacin accumulation in Brassica parachinensis L.

To understand the mechanism controlling cultivar differences in the accumulation of ciprofloxacin (CIP) in Chinese flowering cabbage (Brassica parachinensis L.), low-molecular-weight organic acids (LMWOAs) secreted from the roots of high- and low-CIP cultivars (Sijiu and Cutai, respectively) and their effects on the bioavailability of CIP in soil were investigated. Significant differences in the content of LMWOAs (especially maleic acid) between the two cultivars played a key role in the variation in CIP accumulation.

Occurrence and risk assessment of tetracycline antibiotics in soil from organic vegetable farms in a subtropical city, south China.

This study investigated the occurrence of tetracycline antibiotics in soils from different organic vegetable farms in Guangzhou, a subtropical city, South China and evaluated their ecological risk. Four tetracycline compounds (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) were extracted ultrasonically from soil samples (n = 69), with a solid-phase extraction cleanup, and were then measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results showed that four compounds were detected in all samples, with the concentrations of the individual compounds ranging from 0.

Analysis of Trace Quaternary Ammonium Compounds (QACs) in Vegetables Using Ultrasonic-Assisted Extraction and Gas Chromatography-Mass Spectrometry.

A reliable, sensitive, and cost-effective method was developed for determining three quaternary ammonium compounds (QACs) including dodecyltrimethylammonium chloride, cetyltrimethylammonium chloride, and didodecyldimethylammonium chloride in various vegetables using ultrasonic-assisted extraction and gas chromatography-mass spectrometry. The variety and acidity of extraction solvents, extraction times, and cleanup efficiency of sorbents were estimated to obtain an optimized procedure for extraction of the QACs in nine vegetable matrices. Excellent linearities (R(2) > 0.

Effects of the size and morphology of zinc oxide nanoparticles on the germination of Chinese cabbage seeds.

The toxicity of four zinc oxide nanoparticles (i.e., spheric ZnO-30, spheric ZnO-50, columnar ZnO-90, and hexagon rod-like ZnO-150) to the seed germination of Chinese cabbage (Brassica pekinensis L.

Distribution and risk assessment of quinolone antibiotics in the soils from organic vegetable farms of a subtropical city, Southern China.

Organic fertilizer or manure containing antibiotics has been widely used in organic farms, but the distribution and potential impacts of antibiotics to the local environment are not well understood. In this study, four quinolone antibiotics in soil samples (n=69) from five organic vegetable farms in a subtropical city, Southern China, were analyzed using high performance liquid chromatography-tandem mass spectrometry. Our results indicated that quinolone compounds were ubiquitous in soil samples (detection frequency>97% for all compounds), and their concentrations ranged from not detectable to 42.

[Concentrations of antibiotics in vegetables from manure-mended farm].

Sixteen typical antibiotics including four tetracyclines, four quinolones, and eight sulfonamides in vegetables from manure-amended farm were determined using the ultra high performance liquid chromatography-tandem mass spectrometry and their health risks to human via the diet pathway was assessed. Most antibiotics were frequently detected in vegetable samples, with the detection rate from 11% to 90%. Concentrations of a single compound were mainly less than 5 microg x kg(-1) (D.

Heavy metal contamination of urban soils and dusts in Guangzhou, South China.

The heavy metal concentrations of soil and dust samples from roadside, residential areas, parks, campus sport grounds, and commercial sites were studied in Guangzhou, South China. Heavy metals in samples were determined by inductively coupled plasma atomic emission spectrophotometer following acidic digestion with HClO(4) + HF + HNO(3). High concentrations, especially of Cd, Pb, and Zn, were found with mean concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the urban dusts being 4.

Occurrence of nonylphenol and nonylphenol monoethoxylate in soil and vegetables from vegetable farms in the Pearl River Delta, South China.

Low molecular-mass nonylphenol ethoxylates (NPEOs) and 4-nonylphenol (NP) are biodegradation products of higher molecular mass NPEOs used as surface active agents, and they are endocrine-disrupting contaminants. In this study, surface soil (0-20 cm) samples and different vegetable samples were collected from 27 representative vegetable farms located in Shenzhen, Dongguan, and Huizhou within the Pearl River Delta region, South China, and NP and nonylphenol monoethoxylate (NP(1)EO) were analyzed using high-performance liquid chromatography with ultraviolet detection. The results show that NP and NP(1)EO were detected in soil and vegetable samples.

[Occurrence of quinolone and sulfonamide antibiotics in swine and cattle manures from large-scale feeding operations of Guangdong Province].

The occurrence and distribution of four quinolones and four sulfonamides in swine and cattle feces sampled from twenty large-scale feeding operations in different areas of Guangdong province were detected using solid phase extraction (SPE) and high performance liquid chromatography (HPLC). Quinolone and sulfonamide compounds were observed in all pig dung samples. Their total concentrations ranged from 24.

[Concentrations and distribution of tetracycline antibiotics in vegetable field soil chronically fertilized with manures].

Occurrence of antibiotics in the soils substantially fertilized with antibiotics-enriched animal manures is very of concern. This paper investigated the concentration and distribution of four tetracycline antibiotics in soils from vegetable field chronically fertilized with manures in subtropical area using solid-phase extraction followed by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-MS/MS). The sum concentrations of four tetracycline compounds ranged from 1.

Investigation of sulfonamide, tetracycline, and quinolone antibiotics in vegetable farmland soil in the Pearl River Delta area, southern China.

Thirteen antibiotics in soil from vegetable farmlands of the Pearl River Delta, southern China, were investigated. At least three antibiotics were detected in each sample. Six antibiotics including four quinolones, tetracycline, and sulfamethoxazole were detected in >94% of the samples.

[Preliminary study on occurrence and health risk assessment of quinolone antibiotics in vegetables from Guangzhou, China].

Quinolone antibiotics (QNs) including norfloxacin (NOR), enrofolxacin (ENR), ciprofloxacin (CIP) and lomefloxacin (LOM) in vegetable samples collected from Guangzhou were determined by high performance liquid chromatography (HPLC) coupled with fluorescent detector (FLD). The detected frequency of QNs was 96% in vegetables. The total concentration of quinolones (sigma QNs) detected in vegetable ranged from 1.

[Farm compost polluted water may induce pharyngo-esophageal, gastric and liver carcinoma in the chicken].

Objective: To study farm compost polluted water that may induce pharyngo-esophageal, gastric and liver carcinoma in chickens.

Methods: 280 chickens were randomized into 4 groups: experiment group 100 chickens fed with compost water + NaNO(2) by stomach tube. The other 180 were evenly randomized into 3 control groups (60 each), fed with compost water, NaNO(2) and tap water in the same way.