ABSTRACT
A new method for simultaneous determination of 23 kinds of per-and polyfluoroalkyl substances(PFASs)(13 kinds of perfluoro carboxylic acids,4 kinds of perfluoro sulfonic acids,and 6 kinds of new substitutes)in plant leaf tissue by ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)using automatic online solid phase extraction(SPE)to remove the matrix interference components in plant crude extracts was developed.The plant leaf samples were extracted twice with 1%formic acid-methanol solution,then evaporated to dry,redissolved with 70%methanol solution,and directly injected for analysis.After 23 kinds of target PFASs were purified automatically by online SPE with a WAX column,the six-way valve was switched to rinse PFASs onto an alkaline mobile phase system-compatible C18 analytical column.Then,the 23 kinds of target PFASs were separated within 16 min by gradient elution using a binary mobile phase system of methanol/water(Containing 0.4%ammonium hydroxide).Tandem mass spectrometry was performed in multiple reaction monitoring(MRM)mode for online detection of various PFASs,and quantification was carried out by internal standard method.The results of the method validation showed that satisfactory average recoveries of 23 kinds of PFASs in plant leaf samples(64.2%-125.5%),precision(relative standard deviations(RSDs)of 0.7%-12.8%),linearity(R2＞0.990),and sensitivity(the detection limits(S/N=3)were in the range of 0.02-0.50 μg/kg)were achieved.Finally,this method was used to detect PFASs in the marine green tide algae(Enteromorpha prolifera)and several tree leaves,and a total of 6 kinds of PFASs were detected,in which PFBA was the main contaminant.Compared with the reported offline SPE methods,the proposed online SPE technique significantly simplified the sample pretreatment process and provided an automatic,simple,and environment-friendly method for the routine monitoring of legacy and emerging PFASs in plant tissues.
ABSTRACT
Aims@#This study focused on new fish feed additives that could supply a nutritional value and inhibit or eliminate mycotoxins. Four novel feed additives, including Albizia lebbeck (L.), Leucaena leucocephala leaf extracts, Serendipita indica and Bacillus megaterium were applied to contaminated fish feed; besides investigating the toxicity of these new fish feed additives.@*Methodology and results @#Our data exhibited that the different tested feed additives were not toxic for brine shrimp larvae or fish. Albizia lebbeck extract at a concentration 0.5% was highly effective in detoxifying mycotoxins with efficacy ratios of 88.01%, 93.89% and 92.89% for aflaB1, aflaG1 and CPA, respectively and L. leucocephala at 0.5% had efficacy ratios of 93.52% and 100% for aflaG1 and CPA, respectively. The addition of S. indica with a concentration of 0.75% was highly effective for the usage of good feed approximately free of mycotoxins, with efficacy ratios of 85.65%, 90.81% and 100% for aflaB1, aflaG1 and CPA, respectively. Moreover, B. megaterium, with a concentration of 0.75% was recommended for detoxification. @*Conclusion, significance and impact of study @#Studied new feed additives as feed additives in fish diets to eliminate mycotoxin with the potential of providing antioxidant activity. Results suggest that mycotoxins degradation can happen in vitro and in vivo by applying new fish feed additives in the fish diet.