Determination of selected neonicotinoid insecticides by liquid chromatography with thermal lens spectrometric detection

Abstract

We studied the analysis of trace amounts of neonicotinoid insecticides by liquid chromatography coupled with a thermal lens spectrometric detector (TLS). This multi-residue analysis method is based on the reversed phase separation on C 18 column, isocratic elution and collinear dual beam TLS detection. The insecticides thiamethoxam, imidacloprid, acetamiprid and thiacloprid were detected with retention times of 4.4, 5.7, 6.5 and 8.5 min and limits of quantifications of 50, 89, 10, and 25 lg/L, respectively. The retention times agreed well with those obtained by the same chromatographic method but using a diode-array detector (DAD). The limits of quantifications for imidacloprid were identical in both techniques. However, the limits of quantifications for thiamethoxam, acetamiprid and thiacloprid were up to 8.5 times lower using the TLS detector compared to the diode-array detector. The applicability of the developed procedure was tested on spiked river water and potato samples.

Monitoring of Photocatalytic Degradation of Selected Neonicotinoid Insecticides by Cathodic Voltammetry with a Bismuth Film Electrode

“…Most widely used analytical techniques for the determination of the neonicotinoid insecticides and their degradation products are high-performance liquid chromatography (HPLC) with diode array (DAD) [15,16], mass-spectrometric (MS) [17,18], thermal lens spectrometric (TLS) [19] or electrochemical detectors (ED) [20]. Recently, some alternative techniques like an enzyme-linked immunosorbent assay (ELISA) [21,22], fluorimetry [23], Fourier transform infrared spectroscopy (FTIR) [24] have been employed for the rapid, selective analysis of neonicotinoid containing samples of different origins.…”

Progress in Thermal Lens Spectrometry and Its Applications in Microscale Analytical Devices

“…In the UV region, a frequency-doubled Arþ laser was used for detection of nitroaromatic compounds in contaminated water by a crossed-beam TL system at 257 nm after separation by micellar electrokinetic chromatography (Ragozina et al, 2002), and for detection of neonicotinoids by a TLS system at 244 nm after separation by LC (Guzsv any et al, 2007); the third harmonics (261 nm) of a mode-locked Ti: sapphire laser has been used in a TLM for imaging yeast fungus cells (Harata et al, 2007), and the fourth harmonics (214 nm) was employed in a crossed-beam TL system coupled with micro-HPLC for direct detection of non-labeled amino acids (Katae et al, 2010). Hiki et al (2006) developed a UV-TLM using a high-repetition-frequency (80 kHz) 266 nm UV pulsed laser for detection of nonfluorescent molecules on a microchip.…”

Thermal Lens Spectrometric Detection in Flow Injection Analysis and Separation Techniques

“…A simple and sensitive HPLC-TLS method was reported for simultaneous determination of four neonicotinoid insecticides; i.e., thiamethoxam, imidacloprid, acetamiprid, and thiacloprid (48). The method allows sensitive, selective, and reproducible trace-level determination of these four neonicotinoid insecticides and offers the LODs lower by 2.5 -8.5 times for thiamethoxam (LOD ¼ 15 mg/L), acetamiprid (LOD ¼ 3.2 mg/L), and thiacloprid (LOD ¼ 7.5 mg/L), compared to HPLC-DAD, with similar RSDs.…”