Dissipation, risk assessment, half‐life period and method validation of carbendazim and triazophos in green pea by high‐performance liquid chromatography

Fullerenes engineered nanomaterials are regarded as emerging environmental contaminants. This is as their widespread application in many consumer products, as well as natural release, increases their environmental concentration. In this work, an ultrasonic-assisted pressurized liquid extraction (UAPLE) method followed by high performance liquid chromatography with ultraviolet-visible detector (HPLC-UV-vis) was developed for extraction and determination of fullerene in sediments. The method was validated and found to be suitable for environmental risk assessment. Thereafter, the method was used for the determination of fullerene (C61-PCBM) in sediment samples collected from Umgeni River, South Africa. The current method allows for adequate sensitivity within the linear range of 0.01–4 µg g−1, method limit detection of 0.0094 µg g−1 and recoveries ranged between 67–84%. All the parameters were determined from fortified sediments samples. The measured environmental concentration (MEC) of fullerene in the sediment samples ranged from not detected to 30.55 µg g−1. To the best of our knowledge, this is the first report on the occurrence and ecological risk assessment of carbonaceous fullerene nanoparticles in African sediments and biosolids.

Download Full-text

Decreasing half-life of dieldrin in egg yolk following a single oral administration of aldrin to laying hens

Acta Veterinaria Hungarica ◽

10.1556/004.49.2001.4.10 ◽

2001 ◽

Vol 49 (4) ◽

pp. 465-472

Author(s):

N. Furusawa

Keyword(s):

Body Weight ◽

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Single Dose ◽

Half Life ◽

High Performance ◽

Laying Hens ◽

Egg Yolk ◽

Single Oral Administration ◽

Low Levels

Laying hens were treated orally with a single dose of aldrin (AD) 1 mg/kg body weight. Concentrations (μg/g) of AD or its epoxide (= dieldrin, DD) in the yolk of eggs laid for 21 days after AD treatment were determined by normalphase high-performance liquid chromatography. The limits of determination were 0.02 μg/g for AD and 0.03 μg/g for DD, respectively. After AD treatment, although the low levels of AD (mean 0.02–0.03 μg/g) were observed only during a three-day period (from 4th to 6th days), DD (mean 0.15 μg/g) was found already on the 2nd day, indicating that the epoxidation of AD to DD in the hen’s body is rapid. The highest level of DD (mean 0.40 μg/g) was detected on the 6th day, and then DD levels decreased slowly and were detected up to the 21st day. In this decreasing phase, the half-life of DD in the yolk was estimated to be 25.6 days with a 95% confidence interval from 22.7 to 29.4 days.

Download Full-text

Dry Heat Cooking of Meats as a Source of Airborne N-Nitrosodimethylamine (NDMA)

10.20944/preprints201811.0562.v1 ◽

2018 ◽

Author(s):

Hekap Kim ◽

Jiyeon Tcha ◽

Man-yong Shim ◽

Sungjin Jung

Keyword(s):

Mass Spectrometry ◽

Risk Assessment ◽

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Cancer Risk ◽

High Performance ◽

Average Concentration ◽

Cancer Risk Assessment ◽

Air Samples ◽

Dry Heat

This study aimed to investigate the airborne release of N-nitrosodimethylamine (NDMA) as a result of the dry heat cooking of some meats using charcoal grilling and pan broiling methods. Three types of meat, beef sirloin, pork belly, and duck, were chosen and cooked in a temporary building using the above methods. Air samples were collected in Thermosorb-N cartridges, which were qualitatively and quantitatively analyzed for NDMA using ultra-high performance liquid chromatography–mass spectrometry and high-performance liquid chromatography–fluorescence detection, respectively. Overall, the charcoal grilling method showed higher average NDMA concentrations than the pan broiling method for all types of meat. The highest average concentration was observed for charcoal-grilled beef sirloin (410 ng/m3) followed by pork belly, suggesting that meat protein content and cooking duration are important determinants of NDMA formation. Cancer risk assessment showed that the charcoal grilling of such meats can pose an additional cancer risk for restaurant customers.

Download Full-text