High-pressure liquid chromatographic determination of sec-butylamine residues in potatoes

Fluorescamine, 4-phenylspiro[furan-2(3H), 1′(3′H)-isobenzofuran]-3,3′-dione, derivatives of primary aliphatic amines were separated by high-pressure liquid chromatography using a reverse-phase system with fluorescence detection. This technique was applied to the determination of residues of the fungicide sec-butylamine in potato tubers; the limit of detection was 0.36 pmol, equivalent to a residue of 0.1 mg kg^?1 in potato samples. A second amine, phenethylamine, was identified in extracts from artificially rotted potato flesh but this did not interfere with the analysis of sec-butylamine residues.     

The estimation of residue levels of promacyl and its metabolites in beef tissue and fat by high-performance liquid chromatography with electrochemical detection

A method is described for the estimation of residues of the carbamate insecticide promacyl [5-methyl-m-cumenyl butyryl(methyl)carbamate] and its metabolites that are hydrolysable to isothymol (m-cymen-5-ol), using high-performance liquid chromatography with electrochemical detection to determine the isothymol. Clean-up of samples relied on the steam volatility of phenols. Recoveries at the 0.1 mg kg^?1 level varied from 72–88% for fat tissue and 81–91% for liver. The limits of detection were found to be 0.01 mg kg^?1 for and 0.02 mg kg^?1 for liver. A comparative study of the chromatography of sample extracts using both ultraviolet detection and electrochemical detection showed a substantial decrease in the level of interfering co-eluates in the latter method. A field trial, involving a single spray application of the formulated acaricide on milking cattle, revealed residues in the butter fat comparable with those found in a previous investigation.     

Analysis of soils for diclofop-methyl and diclofop

A method is described for the analysis of soils for residues of the herbicide diclofop-methyl, methyl (RS)-2-[4-(2,4-dichlorophenoxy)phenoxy]propionate, and its breakdown product diclofop, (RS)-2-[4-(2,4-dichlorophenoxy)phenoxy]propionic acid. Diclofop-methyl undergoes hydrolysis in the soil to diclofop, which also has herbicidal activity. A procedure, using a 1% phosphoric acid solution for extraction purposes, has been developed and gives good recoveries of both diclofop-methyl and diclofop at the 0.5 and 0.05 mg kg^?1 levels. After methylation, gas-liquid chromatography with electron-capture detection is used to determine total residue concentrations.     

气相色谱-质谱法测定烟叶和土壤中丁硫克百威及其代谢产物的残留

建立了气相色谱-质谱法同时检测烟叶和土壤中丁硫克百威及其代谢产物(克百威和3-羟基克百威)残留量的分析方法。土壤样品用丙酮-石油醚[V(丙酮)∶V(石油醚)=1∶4]混合溶液提取,无需净化;鲜烟叶样品用丙酮-乙腈[V(丙酮)∶V(乙腈)=1∶9]混合溶液提取;烤后烟叶用乙腈提取。鲜烟叶和烤后烟叶提取液经旋转蒸发浓缩后,用弗罗里硅土柱净化。结果表明:在0.05~1 mg/kg添加水平下,丁硫克百威及其代谢产物的平均回收率在74%~99%之间,相对标准偏差(RSD,n=5)在1.5%~9.2%之间。该方法的前处理相对于萃取过程较简单,其准确度、精密度和灵敏度均符合农药残留分析与检测的技术要求,适合于丁硫克百威及其代谢产物在烟叶和土壤中的残留分析与检测。     

A root bioassay procedure for the determination of chlorsulfuron, diclofop acid and sethoxydim residues in soils

Measurement of the root lengths of pre-ger-minated oat seedlings (Avena sativa L. var. Sioux) grown in the dark in treated soils was used to assay residues of diclofop acid (2-[4-(2,4-dichloro-phenoxy)phenoxy]propionate) and sethoxydim (2-[1-(ethoxyimino)-butyl]-5-[2-(ethylthio)-propy]-3-hydroxy-2-cyclohexene-1-one). Similar measurements involving maize seedlings (Zea Mays L. var. Sunny Vee) were also used to determine residues of the herbicide chlorsulfuron (2-chloro-N-[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbony]benzenesulfonamide) in soils. The procedure appeared to be reproducible with residues of chlorsulfuron, diclofop acid and sethoxydim being detectable at amounts of 0.001, 0.2 and 0.05 μg g^?1 respectively.     

A barn owl feeding study with [14c]flocoumafen-dosed mice: Validation of a non-invasive method of monitoring exposure of barn owls to anticoagulant rodenticides in their prey

A study was carried out to assess the feasibility of monitoring the exposure of barn owls (Tyto alba) to an anticoagulant rodenticide, flocoumafen, by analysis of residues in regurgitated pellets following consumption of flocoumafen-contaminated mice. Mice were fed on a diet containing [¹⁴C]flocoumafen, equivalent to 12 mg kg^?1, and killed 24 h later. A single [¹⁴C]flocoumafen-contaminated mouse was fed to each of four captive barn owls, equivalent to 0·11-0·23 mg kg^?1 per bird, followed on seven successive days by control diet (i.e. undosed mice). The [¹⁴C]flocoumafen dose was eliminated by the owls over the eight-day period in pellets (44%, range 35–55%) and faeces (18%, range 11–21%), with the highest residues being observed in samples from the first 24-h period. Further detailed analysis of the pellets confirmed that flocoumafen residues in the first-day pellets represented 15% (range 8–26%) of the original flocoumafen residues ingested by the barn owls. Calculations based on these data and typical flocoumafen residues in live captured rodents (following baiting) confirm that pellet residue analysis is a sensitive and appropriate method for the non-invasive monitoring of exposure of barn owls to flocoumafen. There were no symptoms of anticoagulant poisoning in any of the birds; two of the birds were successfully paired the next season and produced fledgelings.     

The analysis of crops and soils for the triazine herbicide cyanazine and some of its degradation products. I. Development of method

Radiochemical techniques have been used to develop efficient procedures for the extraction of residues of cyanazine herbicide [‘BLADEX’,

1 BLADEX and FORTROL are Shell registered Trade Marks.

^a ‘FORTROL’,^a 2-chloro-4-(1-cyano-1-methylethylamino)-6-ethylamino-1,3,5-triazine] and its metabolites 2-chloro-4-(1-carbamoyl-1-methylethylamino)-6-ethylamino-1,3,5-triazine ( II ), 2-chloro-4-(1-cyano-1-methylethylamino)-6-amino-1,3,5-triazine ( V ) and 2-chloro-4-(1-carbamoyl-1-methylethylamino)-6-amino-1,3,5-triazine ( VI ) from crops and soils. Partition and column chromatographic techniques have been established for the purification of the extracts. The full analytical procedure is described and the final determination of all four compounds is by g.l.c. with electron capture detection with blank values for field samples generally 0.02 part/million and with good recoveries.     

The dietary toxicity of flocoumafen to hens: Elimination and accumulation following repeated oral administration

In a dietary toxicity study, laying hens received a diet containing the rodenticide flocoumafen at concentrations of 1.5, 5, 10 and 50 mg kg^?1 for five consecutive days. The LC₅₀ at termination following a 28-day observation period was 16.4 mg kg^?1. Livers of birds which received doses of flocoumafen between 5 and 50 mg kg^?1 had concentrations of flocoumafen (1.5 nmol g^?1) that were independent of dose. The data indicate the presence in hen liver of a saturable high-affinity flocoumafen binding site with similar characteristics and capacity to that of the quail and rat. Residues of flocoumafen in samples of breast and leg muscle were low in all exposure groups. Higher, dose-related residues were found in samples of abdominal fat and skin-associated fat and there was a clear demonstration of the transfer of dose-related residues into eggs. In a separate study in which hens were dosed with [¹⁴C]flocoumafen for five consecutive days at a daily rate of 1 and 4 mg kg^?1 body weight, the majority (68 %) of the daily radioactive dose was eliminated over the following 24 hours via excreta. Residues in liver at death or when killed accounted for < 1 % of the cumulative administered radioactivity. Residues in eggs were located primarily in the yolk with maximum concentrations 1.0 mg kg^?1 or 0.18% of the low dose; 2.1 mg kg^?1 or 0.06% of the high dose as [¹⁴C]flocoumafen equivalents were observed at 10 days after start of dosing. Some 40 % of the total activity in the yolk was unchanged flocoumafen.     

A bioassay for determining simazine in water using aquatic flowering plants (Ceratophyllum oryzetorum,Ranunculus trichophyllus and Alisma plantago-aquatica)

A simple and rapid bioassay for the measurement of simazine in water using aquatic flowering plants (Ceratophyllum oryzetorum Kom., Ranunculus trichophyllus Chaix. and Alisma plantago-aquatica L.) is reported in this paper. It is based on the effect of simazine on the amount of oxygen produced by photosynthesis which is measured directly using a Clark-type oxygen electrode. This method is rapid, sensitive, and capable of measuring a simazine concentration of 0.02 mg litre^?1 within 10 min of treatment. The precision of this method was examined with spiked river water by comparing the results obtained with HPLC. Mean recoveries of simazine measured by bioassay using C. oryzetorum were 96 to 100% which were comparable to those (98 to 100%) obtained with C18 column extraction and HPLC measurement. The results obtained by the two methods showed excellent agreement. Maintenance of stock cultures of the plants and the bioassay procedure itself were much simpler and more easily conducted than methods using algae.     

Determination of residues of endosulfan and endosulfan sulfate on eggplant,mustard and chickpea

Extractable residues of endosulfan stereoisomers and its toxic metabolite, endosulfan sulfate, on a vegetable, an oilseed and a pulse crop were determined by gas-liquid chromatography. The study revealed that the alpha isomer degraded faster than the beta isomer. Beta-endosulfan accumulated during the first three days following the treatment. Endosulfan sulfate residues appeared a few days after application and decreased with time. The total endosulfan residues in the seeds from treated mustard ranged from 0.08 to 0.12 mg kg^?1 and were at or below the limit of determination (0.02 mg kg^?1) in chickpea seeds following harvest.     

Residues of diflubenzuron and two of its metabolites in a forest ecosystem after control of the pine looper moth,Bupalus piniarius L

Diflubenzuron, 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea was used to control the pine looper population in about 1160 ha of Scots pine stand in eastern Finland in summer 1984. The control measure was effective, resulting in the collapse of the population in the treated area. Residues of diflubenzuron and two of its metabolites, 4-chloroaniline and 4-chlorophenylurea, were determined in water, pine needles, litter, humus, boleti and other wild mushrooms, bilberry (Vaccinium myrtillus L.) and cowberry (Vaccinium vitis-idaea L.) samples taken from this area. In water samples taken from the treated area diflubenzuron was still detected at concentrations of 0.1 μg litre^?1 2 months after application. No diflubenzuron was detected in this area the following year, nor outside the treated area. Neither metabolite was detected at any time. The sum of diflubenzuron and its metabolites in the litter layer was, on average, 0.7mg kg^?1 both 1 week and 1 month after the application. The next year, however, it had increased to 1.4 mg kg^?1. Diflubenzuron and its metabolites were not detected in the humus layer. The amount of diflubenzuron residues in the pine needles was, on average, 3.0 mg kg ^?1 1 day after the application, but in 2 months the level had decreased to 0.2-0.3 mg kg ^?1 or was not detectable. The following year the sum of diflubenzuron and its metabolites in two pine-needle samples was 0.3 and 1.6 mg kg ^?1. The sum of diflubenzuron and its metabolites in wild mushrooms was, on average, 0.07 mg kg ^?1 1 week after the application, but the following year no residues were detected. No residues were found in the boletus samples. The residues of diflubenzuron and its two metabolites in bilberries totalled, on average, 0.2 mg kg ^?1 1 day after the application, and 6 μg kg ^?1 the following year. The sum of diflubenzuron and metabolites in cowberries was, on average, 0.2 mg kg ^?1 1 month after application.     

气相色谱-串联质谱法测定莲雾中的灭蚁灵和哒螨灵残留

建立了同时测定莲雾Syzygium samarangense(Bl.)Merr.et Perry中灭蚁灵和哒螨灵残留的气相色谱-串联质谱(GC-MS/MS)分析方法。样品经乙腈匀浆提取,石墨化碳黑/氨基混合型固相萃取柱净化,GC-MS/MS检测。采用所建立的方法,在0.01~0.5 mg/kg下进行添加回收试验,2种农药的平均回收率在89%~102%之间,相对标准差为1.7%~5.2%(n=5);方法的线性范围为0.01~0.5 mg/L,决定系数(R2)0.99;对灭蚁灵和哒螨灵的定量限均为0.005 mg/kg。所建方法能满足莲雾中灭蚁灵和哒螨灵残留同时检测的要求。     

Acaricides and their residues in Spanish commercial beeswax

BACKGROUND: The purpose of this work was to determine residues of acaricides in recycled Spanish beeswax. RESULTS: Chlorfenvinphos, fluvalinate, amitraz, bromopropylate, acrinathrin, flumethrin, coumaphos, chlorpyrifos, chlordimeform, endosulfan and malathion residues were determined by GC‐µECD/NPD/MS detection. Owing to the extreme instability of amitraz, this analyte was transformed into the stable end‐metabolite 2,4‐dimethylaniline, later derivatised with heptafluorobutyric anhydride and determined by GC‐µECD/MS. Recoveries from spiked samples ranged from 86 to 108%, while quantification limits varied from 0.10 to 0.30 mg kg^?1 using GC‐µECD/NPD, and from 12 to 85 µg kg^?1 by GC‐MSD. Of a total of 197 samples analysed, only eight samples (4%) were free of residues of chlorfenvinphos (0.019–10.6 mg kg^?1), fluvalinate was present in 93.6% of samples analysed (0.027 –88.7 mg kg^?1), while coumaphos was confirmed in only five of the 134 samples analysed at concentrations of less than 195 µg kg^?1. The remaining acaricides were identified with different levels of incidence at concentrations from 12 to 231 µg kg^?1. CONCLUSIONS: Residues of acaricides were found in an extensive number of beeswax samples. The contamination with chlorfenvinphos and tau‐fluvalinate was very relevant, particularly as chlorfenvinphos is not legally authorised for use in beekeeping. The possible impacts of the main acaricides detected on larval and adult honey bees are discussed. Copyright © 2010 Society of Chemical Industry     

Effects of repeated applications of ten soil-active herbicides on weed population,residue accumulation and nitrification*

Ten herbicides, bromacil, chlorthal-dimethyl, diphenamid, diuron, fluometuron, neburon, prometryne, pyrazon, simazine and trifluralin at two doses were repeatedly sprayed, in autumn and in spring, for 4 consecutive years on non-cultivated, sprinkler-irrigated field plots. Herbicidal effect was assessed at 1–2 month intervals on the natural weed population and after each observation a paraquat + diquat spray destroyed emerged weeds. The response of various weed species to herbicides varied markedly but a herbicide-induced shift in the composition of weed population did not occur, presumably because of the paraquat treatment. The overall phytotoxicity to weeds present was, in decreasing order: diuron, bromacil, simazine, trifluralin, prometryne, neburon, fluometuron, pyrazon, diphenamid, chlorthal-dimethyl. Persistence of herbicides was in decreasing order: diuron = bromacil, simazine, neburon (at higher rate), fluometuron, trifluralin, prometryne. Control produced by pyrazon improved with the number of applications, but that of diphenamid and chlorthal-dimethyl remained weak and short. After repeated applications, the activity of these herbicides increased or remained at similar level, but in no case decreased. Soil samples were taken 5 months after each application and bioassayed. Phytotoxic residues were detected beneath the disturbed top-soil from bromacil, diuron, fluometuron and simazine after the first application, and from neburon after the second application; residues from trifluralin were found in the top soil only after the fifth application. After the seventh spraying, residues of bromacil were found in the 45–60-cm soil layer. Ammonia content in soil samples taken from treated plots after the fourth, sixth and seventh application was generally similar to the untreated control. In these samples, nitrate content appeared to be correlated negatively with remaining weed number; the control thus contained less nitrate than efficient herbicidal treatments. Soil samples taken after the seventh application of bromacil, diuron, fluometuron, neburon and simazine, which contained appreciable residual concentrations, did not show significant differences from control, in an in vitro nitrification test.     

高效液相色谱法测定糙米和土壤中6种杀虫剂的残留

建立了糙米和土壤中氟啶虫酰胺、氯虫苯甲酰胺、甲氧虫酰肼、氟虫双酰胺、虫螨腈和虱螨脲6种杀虫剂残留的高效液相色谱检测方法。样品用乙腈浸泡过夜后振荡提取,其中糙米过氨基小柱净化,土壤无需净化;采用高效液相色谱仪,以甲醇-乙腈-水为流动相,利用C18柱和二极管阵列检测器(检测波长:265、254、230 nm)对待测组分进行分离和测定。结果表明,在0.05~5 mg/L范围内,标准品质量浓度与峰面积之间呈良好的线性关系(R2=0.999 4~1)。在0.1、0.5和1 mg/kg 3个添加水平下,糙米和土壤中氟啶虫酰胺、氯虫苯甲酰胺、甲氧虫酰肼、氟虫双酰胺、虫螨腈和虱螨脲的平均回收率在84.5%~113.2%之间,相对标准偏差(RSD)≤9.3%;供试6种农药在样品中的检出限(LOD)为0.010~0.016 mg/kg,定量限(LOQ)为0.03~0.05 mg/kg。所建 立的方法具有准确、快速、简便、重复性好等特点,其准确度和精密度均能满足农药残留分析的要求。     

Insect growth inhibition,antifeedant and antifungal activity of compounds isolated/derived from Zingiber officinale Roscoe (ginger) rhizomes

Fresh rhizomes of Zingiber officinale (ginger), when subjected to steam distillation, yielded ginger oil in which curcumene was found to be the major constituent. The thermally labile zingiberene‐rich fraction was obtained from its diethyl ether extract. Column chromatography of ginger oleoresin furnished a fraction from which [6]‐gingerol was obtained by preparative TLC. Naturally occurring [6]‐dehydroshogaol was synthesised following condensation of dehydrozingerone with hexanal, whereas zingerone and 3‐hydroxy‐1‐(4‐hydroxy‐3‐methoxyphenyl)butane were obtained by hydrogenation of dehydrozingerone with 10% Pd/C. The structures of the compounds were established by ¹H NMR, ¹³C NMR and mass (EI‐MS and ES‐MS) spectral analysis. The test compounds exhibited moderate insect growth regulatory (IGR) and antifeedant activity against Spilosoma obliqua, and significant antifungal activity against Rhizoctonia solani. Among the various compounds, [6]‐dehydroshogaol exhibited maximum IGR activity (EC₅₀ 3.55 mg ml ^?1) while dehydrozingerone imparted maximum antifungal activity (EC₅₀ 86.49 mg litre^?1). © 2001 Society of Chemical Industry     

The comparative behaviour of simazine and terbacil in soils

Adsorption of simazine (2-chloro-4,6-bisethyl-amino-1,3,5-triazine) was 2.2–4 times greater than that of terbacil (5-chloro-6-methyl-3-t-butyl-uracil) in the same soils and adsorption of both herbicides was 2–4 times greater in the topsoils than subsoils. Adsorption was inversely correlated with herbicide movement in a thick-layer chromatography system. One year after application of 3 kg/ha to field plots, simazine residues were highest near the soil surface, whereas terbacil residues increased with soil depth in the sandy and sandy loam soils. Total residues recovered from the upper 25 cm of soils was 5% or less of the simazine originally applied, and 10% or less of the applied terbacil. In an oat seedling bio-assay, the GR₅₀ values were generally 1.5–3 times higher for simazine than for terbacil in the same soils.     

Development of methods for the analysis of crops and soils for residues of benzoylprop-ethyl and its breakdown products

Methods are described for the analysis of residues of the herbicide benzoylpropethyl, ethyl (±)-2-[ N-(3,4-dichlorophenyl)benzamido]propionate, and its breakdown product, (±)-2-[ N-(3,4-dichlorophenyl)benzamido]propionic acid, in wheat and soil. In wheat the acid degradation product conjugates with plant sugars and the present paper includes methods for determination of these residues either separately or as a combined residue with unconjugated acid. Efficient extraction procedures have been developed together with partition and column chromatographic techniques for purification of extracts. The full analytical procedures are described and the final determinations are by g.1.c. with electron capture detection with blank values for field samples in the range 0.01–0.05 mg/kg. Good recoveries were obtained. Radiochemical techniques have been used to verify the extraction and subsequent procedures in the methods.     

高效液相色谱法检测环氧虫啶在柑橘及土壤中的残留

建立了环氧虫啶在柑橘和土壤中残留量测定的高效液相色谱(HPLC-UVD)分析方法。柑橘样品采用V(蒸馏水):V(二氯甲烷)=1:2提取后经弗罗里硅土柱净化(土壤样品提取后直接测定),HPLC-UVD测定,外标法定量,并运用此方法对田间样品进行了环氧虫啶残留量检测验证。结果表明:在0.05~5mg/L范围内,环氧虫啶质量浓度与对应的峰面积间呈良好线性关系,线性方程为y=10243x+233.0(R2=0.9990);土壤和柑橘中环氧虫啶的最低检测浓度均为0.1mg/kg;在0.1~1mg/kg3个添加水平下,环氧虫啶在土壤和柑橘中的平均回收率在76%~93%之间,相对标准偏差(RSD,n=5)在1.6%~5.8%之间。该方法快速、灵敏、稳定,可用于柑橘和土壤中环氧虫啶残留量的检测。     

Metabolism and cell wall incorporation of phenoxyacetic acid in soybean cell suspension culture

The metabolism of [¹⁴C]phenoxyacetic acid (POA) was studied in cell suspension culture of soybean (Glycine max). POA was metabolized to 4-HO-POA, 4-HO-POA glucoside and 4-HO-POA glycosidic ester. A large part of the 4-HO-POA glucoside and small amounts of the glycosidic ester were recovered in the medium. POA was also converted to non-extractable residues bound to cell walls. Sequential extraction of cell-wall polymers showed that non-extractable residues, partly identified with 4-HO-POA and POA, were mainly associated with hemicelluloses and lignin. Comparison of the metabolism of [carboxy-¹⁴C]- and [phenyl-¹⁴C]POA revealed some degradation of the POA side-chain, followed in all probability by the incorporation of the aromatic moiety into cell walls. However, the sturdiness of the resulting bonds prevented precise identification of these bound aromatic structures. In summary, the degradation of POA in soybean cell culture provided a good model to study the formation of non-extractable residues of pesticides. © 1999 Society of Chemical Industry