Recovery of s‐triazine herbicides and associated breakdown products from granular activated carbon using supercritical fluid extraction

Robertson, A. MacG.; Lester, J.N.

doi:10.2175/106143095x133112

Cited by 9 publications

(2 citation statements)

References 22 publications

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“…The mean recoveries varied from 73.4 to 90.4% with the recovery of atrazine, the most widely used triazine, being the highest, 90.4 ( 3.3%. These results compare favorably to those reported for other SFE methods that use SC-CO 2 (Janda et al, 1989;Barnabas et al, 1994;Papilloud and Haerdi, 1994;Robertson and Lester, 1995;Alzaga et al, 1996). Most of these applications have been applied to environmental samples, especially soils.…”

Section: Resultssupporting

confidence: 85%

Supercritical Fluid Extraction of Atrazine and Other Triazine Herbicides from Fortified and Incurred Eggs

Pensabene

Fiddler

Donoghue

2000

J. Agric. Food Chem.

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Triazines are a class of important pre-emergent weed herbicides. Some members of this class of herbicides exhibit carcinogenic and immunotoxicity properties, which make their use controversial in areas where animal feed crops are grown. It is therefore important to determine if triazine residues are transported to animal food products in order to ascertain the extent of human exposure. Most of the current herbicide residue extraction methods are time-consuming and solvent intensive. Supercritical fluid extraction (SFE) using CO 2 has been used as a alternative for other residue extraction methods as a replacement for hazardous organic solvents. In this study, 10 triazines were extracted from eggs fortified at 100 ppb using unmodified supercritical CO 2 at a pressure of 10000 psi and a temperature of 50 °C with off-line collection on a solid phase extraction cartridge containing Florisil. Atrazine recovery averaged 90.4% with an RSD of 3.3%. The other triazines were recovered at mean levels >73%. In a separate feeding study, atrazine and two of its dealkyl metabolites were detected in the egg. The results indicate that SFE is a viable technique for isolating triazine residues from eggs, requiring only 8 mL of solvent for each analysis.

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Section: Resultssupporting

confidence: 85%

Supercritical Fluid Extraction of Atrazine and Other Triazine Herbicides from Fortified and Incurred Eggs

Pensabene

Fiddler

Donoghue

2000

J. Agric. Food Chem.

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“…On the opposite the more polar metabolite was hardly extracted (20%); the use of methanol containing 2% (v/v) of water as a modifi e r enhanced its recovery (52%). Similarly, the SFE of atrazine, simazine, deethylatrazine (DEA) and deethylsimazine (DES) from granular activated carbon (GAC) has been investigated, as GAC filters are frequently used in potable water treatment for the re m oval of traces of pesticides [76]. Almost no extraction occurred using pure CO 2 , due to very strong interactions between active sites of the carbon and pesticides.…”

Section: Food Itemsmentioning

confidence: 99%

Supercritical fluid extraction as a useful method for pesticides determination

Camel¹

1998

Analusis

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Despite attractive features (rapid extractions, small solvent volumes, non-toxicity of CO 2 , potential of selectivity depending on the fluid density, relatively clear and concentrated ex t ra c t s , p o s s i ble coupling with ch romatography and automation), the use of SFE in routine analytical ap p l i c ations is a rather slow process. Indeed, t h e major drawback of this recent technique is the large number of parameters to control and optimize, which results in time re q u i red for developing a new method. In add i t i o n , t h e extraction conditions are strongly dependent on the matrix to be extracted, so that parameters need to be adjusted for every new application. D e t e rm i n ation of pesticides remains a ch a l l e n ge fo r mainly three reasons: the wide variety of physicochemical properties and chemical structures of pesticides, the many possible matrices that should be investigated, and the trace c o n c e n t rations at wh i ch pesticides are usually pre s e n t . Recent papers reviewed environmental applications of SFE [1,2], especially with regards to the extraction of the main classes of pesticides [3][4][5]. As SFE perfo rmances are strongly dependent on the nature of the sample, this article will consider the matrices that have been submitted to SFE for pesticides determination. Principle of SFEA fluid is in its supercritical state when both its pressure and temperature are above their critical value (when only one c ritical value is at t a i n e d, the fluid is said subcri t i c a l ) . Supercritical fluids possess unique properties, intermediate between gas and liquids properties [6][7][8][9][10]. In particular, their high diffusivity allows for rapid extractions. In addition, the fluid density may be precisely adjusted, by a correct choice of both pressure and temperature.The key parts of an SFE system are the high-pressure pump wh i ch delive rs the fl u i d, and the re s t rictor wh i ch maintains the pressure inside the system. Extraction is performed inside a high-pressure cell (containing the sample), maintained at the correct temperature. The fluid may simply fill the cell (static mode), or continuously flow through the vessel (dynamic mode). The extracted solutes are entrained by the supercritical fluid flow out of the cell; their collection is usually achieved as the fluid is depressurized by passing through the restrictor. The collected solutes are further analyzed using gas or liquid chromatography. Also, a few recent studies report the use of enzyme immunoassay as a rapid screening process [5,11,12]. Alternatively, the SFE system may be coupled on-line with chromatographic systems, gas chromatography (GC), liquid chromatography (LC), or supercritical fluid chromatography (SFC), by means of an interface [5,8]. For example, the coupling of SFE and SFC e n abled the determ i n ation of thiolcarbamate herbicides (molinate and thiobencarb) from spiked soil samples (with organic content from 1.75 to 12.9%) [13]. Obviously, such a system seems very attractive when traces of pest...

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