Dissipation, Residue, and Dietary Risk Assessment of Methoxyfenozide, Chlorantraniliprole, Indoxacarb, Lufenuron, and Chlorfenapyr in Spinach Using a Modified QuEChERS Method Combined with a Tandem Mass Spectrometry Technique

Abstract

Spinach is a frequently consumed vegetable worldwide. Chemical pesticides are widely used to produce spinach with high yield and quality. However, the unregulated use of pesticides negatively impacts human and environmental health. A simple and efficient method using dispersive solid-phase extraction (d-SPE) combined with field experiments was conducted to study the residue dissipation of methoxyfenozide, chlorantraniliprole, indoxacarb, lufenuron, and chlorfenapyr in spinach under different planting conditions. The results showed that the half-lives of methoxyfenozide, chlorantraniliprole, indoxacarb, lufenuron, and chlorfenapyr in spinach were 1.1–3.0 d, 2.6–4.0 d, 1.7–4.2 d, 3.4–4.4 d, and 2.8–4.3 d, respectively. The five pesticides rapidly degraded without significant differences between the open and greenhouse fields. The final residue of indoxacarb in spinach was not higher than the maximum residue limit (MRL) in China (3 mg kg−1); the highest residual value was 1.0 mg kg−1. Although the MRLs of methoxyfenozide, chlorfenapyr, and lufenuron for spinach are yet to be formulated in China, the long-term dietary risk for the four pesticides was acceptable, with an RQ < 100%, according to the international and national assessments. These results are necessary to provide guidance for the proper and safe use of these pesticides.

Environmental fate and safety analysis of methoxyfenozide application to control litchi and longan pests

“…The vapor pressure, partition coefficient, and water solubility of methoxyfenozide were < 1.33 × 10 −5 Pa, log Pow 3.72 ± 0.04 at 24.7 ± 1.4 ℃ (pH 7), and 3.3 mg/L at 20 ± 0.5 ℃ (pH 7), and 3.3 mg/L methoxyfenozide, 2003). The methoxyfenozide dissipation rates of litchi and longan were slower than those previously reported for pak choi (initial concentrations = 2.8 mg kg −1 , half-life = 3.9 days) (Tang et al 2021 ), spinach (initial concentrations = 1.2–3.8 mg kg −1 , half-life = 1.4–3.0 days) (Feng et al 2022 ), Chinese cabbage (initial concentrations = 1.12–1.33 mg kg −1 , half-life = 1.2 days) (Wang et al 2022 ), Chinese broccoli (initial concentrations = 0.27–1.73 mg kg −1 , half-life = 1.0–5.1 days) (Bi et al 2021 ), and cauliflower (initial concentrations = 2.5–3.5 mg kg −1 , half-life = 0.14–4.38 days) (Sun et al 2019a , b ). The above reports include residue levels observed in vegetables and pesticide degradation during harvesting is generally faster due to the short growth cycle of vegetables.…”

“…Generally, to elucidate the possibility of dietary intake-related chronic or acute harm to consumer’s health, ADI% values are employed (Feng et al 2022 ; Wang et al 2022 ). The ADI% values were assessed based on the results of the residue trial via the following formula: where STMR (mg kg −1 ) is the median pesticide residue levels calculated for litchi and longan, bw (kg) is the body weight, and F (kg) is the average daily fruit intake in China.…”

“…Generally, to elucidate the possibility of dietary intakerelated chronic or acute harm to consumer's health, ADI% values are employed (Feng et al 2022;Wang et al 2022). The ADI% values were assessed based on the results of the residue trial via the following formula:…”

Exploring the Potential of Microextraction in the Survey of Food Fruits and Vegetable Safety

“…Consequently, it was able to extract a broader range of pesticides and achieved recovery levels of 60-120% (RSD values of 2-28%) and LODs of 0.5-1 µg kg −1 . The use of QuEChERS/dSPE as an extraction approach for multi-residue analysis has become very popular and many more examples can be found in the literature [89][90][91][92][93]. Woldetsadik et al [94] used QuEChERS/HS-SPME coupled with GC-MS for the determination of DDT congeners and four HCH isomers in khat samples.…”

“…This is essentially a clean-up procedure that can follow different extraction procedures, although its sole use has been already reported [118,119]. Eventually, dSPE's most popular use is associated with QuEChERS, a procedure that we included both in Table 1, devoted to conventional extraction procedures [88][89][90][91][92][93]107,108], as well as in Table 2, that presents microextraction approaches. The reason for this is that the miniaturization of QuEChERS (µQuEChERS) is being pursued by different researchers and the examples presented in Table 2 are variations of the original protocol downscaled to a microextraction format.…”