A quantitative solid-state Raman spectroscopic method for control of fungicides

Abstract

A new analytical procedure using solid-state Raman spectroscopy within the THz-region for the quantitative determination of mixtures of different conformations of trifloxystrobin (EE, EZ, ZE and ZZ), tebuconazole (1), and propiconazole (2) as an effective method for the fungicide product quality monitoring programmes and control has been developed and validated. The obtained quantities were controlled independently by the validated hybrid HPLC electrospray ionization (ESI) tandem mass spectrometric (MS) and matrix-assisted laser desorption/ionization (MALDI) MS methods in the condensed phase. The quantitative dependences were obtained on the twenty binary mixtures of the analytes and were further tested on the three trade fungicide products, containing mixtures of trifloxystrobin-tebuconazole and trifloxystrobin-propiconazole, as an emissive concentrate or water soluble granules of the active ingredients. The present methods provided sufficient sensitivity as reflected by the metrologic quantities, evaluating the concentration limit of detection (LOD) and quantification (LOQ), linear limit (LL), measurement accuracy and precision, true quantity value, trueness of measurement and more.

Rapid microwave-assisted synthesis of molecularly imprinted polymers on carbon quantum dots for fluorescent sensing of tetracycline in milk

“…As shown in Fig. S7 (ESI †), the detection limit, calculated based on a 3σ/slope [39,40], was down to 5.48 nmol L -1 , which is lower or at least comparable to the sensors reported in recent years [18][19][20][21][22]. Meanwhile, the precision and reproducibility of the proposed sensor were also acceptable.…”

Study of the Degree of Cure through Thermal Analysis and Raman Spectroscopy in Composite-Forming Processes

“…The ratio between the intensities of both D and G bands gives us an idea of the crystalline order of the sample. The crystalline size, L a , is derived from the Knight formula [14,15], La(nm)=false(2.4×10−10false) λ4(IDIG)−1 where λ is the laser line wavelength in nanometer units, and I D and I G are the intensities of the D and G bands, respectively [16,17]. The values for the crystalline order and crystallite sizes for the composite samples with different cure degrees are displayed in Table 8.…”

In situ chemically specific mapping of agrochemical seed coatings using stimulated Raman scattering microscopy

“…However, conventional analytical tools fall short of this requirement. Various methods, including HPLC‐mass spectrometry measurement , Raman spectroscopy , X‐ray Micro‐CT , and near infrared hyperspectral spectroscopy have been utilized to analyze the distribution of agrochemicals on the seed surfaces. However, these techniques suffer from a number of drawbacks such as lengthy sample preparation of seed sections , loss of spatial resolution, long acquisition times or lack of chemical specificity for the AIs .…”

“…Various methods, including HPLC‐mass spectrometry measurement , Raman spectroscopy , X‐ray Micro‐CT , and near infrared hyperspectral spectroscopy have been utilized to analyze the distribution of agrochemicals on the seed surfaces. However, these techniques suffer from a number of drawbacks such as lengthy sample preparation of seed sections , loss of spatial resolution, long acquisition times or lack of chemical specificity for the AIs . Labeling of the AI molecules with fluorophores has also been used to evaluate seed coatings , however the low molecular weight of most AIs means that fluorescent derivatization has a direct impact on their chemical‐physical properties which makes interpretation of the results difficult and potentially misleading.…”