Separation and determination of triadimefon and its metabolites triadimenol enantiomers in fruit puree by supercritical fluid chromatography

A method was established for the separation and determination of triadimefon and its metabolite triadimenol enantiomer residues in major complementary fruit puree for infants and young children (banana puree, pineapple puree, and grape puree) by supercritical fluid chromatography. After the samples were extracted with acetonitrile and purified with a solid phase extraction cartridge, Acquity Trefoil CEL2 chiral chromatographic column was adopted for separation, and gradient elution was conducted at the flow rate of 1.0 ml/min under the mobile phase of supercritical carbon dioxide - 0.5% ammonia methanol, the detection wavelength was 220 nm and quantification was conducted with the external standard method. The limits of quantitation of triadimefon and triadimenol enantiomers were both 0.05 mg/kg, the linear ranges were 0.5–50 mg/L, and the linear correlation coefficients were greater than 0.9993. The recoveries in the spiked samples at 0.05, 0.2, and 3.0 mg/kg were from 80.1 to 106%, and the relative standard deviation reached 3.3–7.6%. The method is efficient, rapid, reproducible, and environmentally friendly, enabling accurate analysis of pesticide enantiomers, which can detect the enantiomer residues of triadimefon and its metabolite triadimenol in major complementary fruit puree for infants and young children.     

高效液相色谱法测定强化食品中维生素C的含量

建立了强化食品(饮料、奶粉、含乳饮料、大米、果泥及果冻)中维生素C含量的高效液相色谱检测方法。优化了样品处理方法,在水浴控温和避光条件下处理样品,避免维生素C被氧化。选用Tech Mate C18–ST(250 mm×4.6 mm,5μm)反相色谱柱,以0.05 mol/L磷酸二氢钾缓冲溶液(p H 3)为流动相,流量为1.0m L/min,检测器为光电二极管阵列检测器,检测波长为266 nm。线性范围为0.2~100μg/m L,相关系数为0.999 6,果泥中维生素C的定量限为20 mg/kg,其它为100 mg/kg,加标回收率为82.2%~107%,测定结果的相对标准偏差为1.23%~6.86%(n=8)。该方法简单快速,其灵敏度、准确度和精密度均能满足强化食品中维生素C的检测要求。     

高效液相色谱-串联质谱法测定食品中20种氨基甲酸酯类农药残留

建立了食品中20种氨基甲酸酯类农药残留量的高效液相色谱-串联质谱联用(HPLC-MS/MS)测定与确证方法。20种氨基甲酸酯类农药在0.005～0.1 mg/kg范围内线性良好,相关系数为0.991 7～0.999 6;在0.005～0.025 mg/kg范围内, 20种目标物的回收率为51.2%～125.0%,相对标准偏差为1.4%～19.8%。该方法准确、灵敏、快速,可满足国际上对食品中这20种氨基甲酸酯类农药残留量的检测需要。     

微波辅助提取-气相色谱法同时测定中草药中有机磷和氨基甲酸酯农药残留

建立了中草药中有机磷和氨基甲酸酯类农药同时检测的气相色谱分析新方法.中药材试样依据正交实验的优化条件,用正己烷-丙酮(1∶4,V∶V)混合提取剂进行微波辅助提取,经弗罗里硅土和中性氧化铝混合层析柱净化后,采用HP-5毛细管柱分离,氮磷检测器同时检测中草药中15种有机磷和6种氨基甲酸酯类农药残留量.21种农药在0.01～1.0 mg/L的浓度范围内线性良好,线性相关系数为0.9950～1.000,检出限为0.002～0.01 mg/L.在0.05、0.2、0.5 mg/kg三个添加水平的平均回收率分别为75.11%～128.57%、75.85%～120.71%和76.43%～117.25%,相对标准偏差分别为 3.10%～10.58%、5.27%～9.94%和4.03%～9.03%.方法用于中草药中有机磷和氨基甲酸酯类农药残留的同时检测,结果良好.     

Simultaneous determination of 22 phthalate esters in polystyrene food‐contact materials by ultra‐performance convergence chromatography with tandem mass spectrometry

A method for the determination of 22 phthalate esters in polystyrene food‐contact materials has been established using ultraperformance convergence chromatography with tandem mass spectrometry. In this method, 22 phthalate esters were analyzed in <3.5 min on an ACQUITY Tours 1‐AA column by gradient elution. The mobile phase, the compensation solvent, the flow rate of mobile phase, column temperature, and automatic back pressure regulator pressure were optimized, respectively. There was a good linearity of 20 phthalate esters with a range of 0.05–10 mg/L, diisodecyl phthalate and diisononyl phthalate were 0.25–10 mg/L, and the correlation coefficients of all phthalates were higher than 0.99 and those of 16 phthalates were higher than 0.999. The limits of detection and the limits of quantification of 15 phthalates were 0.02 and 0.05 mg/kg, meanwhile diallyl phthalate, diisobutyl phthalate, dimethyl phthalate, di‐n‐butyl phthalate, and di(2‐ethylhexyl) phthalate were 0.05 and 0.10 mg/kg, and diisodecyl phthalate and diisononyl phthalate were 0.10 and 0.25 mg/kg. The spiked recoveries were in the range of 76.26–107.76%, and the relative standard deviations were in the range of 1.78–12.10%. Results support this method as an efficient alternative to apply for the simultaneous determination of 22 phthalate esters in common polystyrene food‐contact materials.     

Determination of chlormequat and mepiquat in foods by liquid chromatography/mass spectrometry or liquid chromatography/tandem mass spectrometry: interlaboratory study

Interlaboratory validation studies have been performed on 2 methods for the determination of chlormequat (CLQ) and mepiquat (MPQ). Both methods used identical extraction procedures and stable isotope internal standardization but differed in the use of liquid chromatography/mass spectrometry (LC/MS) or LC/tandem mass spectrometry (LC/MS/MS) for the determination, the amount of internal standard used, and the expected limit of detection. After addition of deuterated internal standards, CLQ and MPQ were extracted with methanol-water and determined by LC//MS or LC/MS/MS with positive electrospray ionization. Eight European laboratories participated in the LC/MS method study, analyzing mushroom, pear, wheat flour, and fruit puree with residues of CLQ in the range 0.040-1.19 mg/kg and of MPQ in the range 0.041-0.39 mg/kg. For CLQ, the Horwitz ratio (HoRat) values for individual test materials/levels were in the range 0.85-1.13 with a mean of 1.00, showing good method performance. For MPQ, the Ho values for mushroom, pear (both levels), and wheat flour were in the range 0.83-0.94, again indicating good method performance. For the determination of MPQ in infant food (fruit puree) at 0.041 mg/kg, the Ho was 1.7 when a value of 0 reported by one participant was excluded. In the LC/MS/MS study, in which 11 laboratories participated, a separate sample set was analyzed with residues of CLQ in the range 0.007-1.03 mg/kg and of MPQ in the range 0.008-0.72 mg/kg. Ho values for CLQ were in the range 0.27-1.36 and for MPQ in the range 0.51-2.10, all corresponding to acceptable method performance.     

高效液相色谱-串联质谱法测定水果中残留的烯唑醇

建立了水果中烯唑醇残留量的高效液相色谱-串联质谱（LC-MS/MS）测定方法。样品采用丙酮-正己烷液液振荡提取,经分散固相萃取（DSPE）净化后,采用ODS-C18柱为分离柱,以乙腈-0.1％甲酸溶液为流动相,采用液相色谱-串联质谱(ESI)多反应监测（MRM）正离子模式测定,外标法定量。烯唑醇在0.002～0.2 mg//L质量浓度范围内线性关系良好,方法定量下限（LOQ）为0.001 mg/kg。在0.005～0.1 mg/kg之间的3个添加浓度水平下,添加回收率为78.8 %~108.0 %,相对标     

超高效液相色谱-串联质谱法检测婴幼儿辅助食品中多种兽药残留

生产婴幼儿辅助食品的原辅料中常常含有鱼类、肉类、肝类等动物性组织,存在兽药残留的风险,为了更加全面地对这类产品进行安全监管,研究并开发了同时检测婴幼儿辅助食品中6大类(喹诺酮类、磺胺类、大环内酯类、硝基咪唑类、氯霉素类和抗病毒类)50种抗生素和抗病毒类兽药残留的超高效液相色谱-三重四极杆质谱法(UPLC-MS/MS)。样品采用酸化乙腈超声提取,提取液经新型的脂质增强型Captiva EMR-Lipid固相萃取柱净化,浓缩复溶后采用流动相乙腈和0.1%(v/v)甲酸水溶液,经C18柱梯度洗脱分离,电喷雾多反应监测(MRM)模式检测,基质匹配外标法定量。结果显示,该方法50种兽药在0.5~50 μg/L范围内线性关系较好,相关系数均不低于0.995,方法检出限为0.03~0.70 μg/kg,定量限为0.09~2.33 μg/kg。50种化合物在不同基质中,添加5和50 μg/kg两个加标水平进行试验,平均回收率为64.37%~119.3%,相对标准偏差均小于15%。将该方法应用于14份国产和6份进口的婴幼儿辅助食品检测,结果显示,1份进口肉类婴幼儿辅助食品中检出磺胺喹噁啉、磺胺二甲嘧啶和替米考星。该方法简单快速,灵敏度和准确度高,样品量消耗少,适用于婴幼儿辅助食品中多种兽药残留的检测。     

串联双柱固相萃取-液相色谱-串联质谱法测定番茄酱中链霉素和双氢链霉素残留量

建立了同时测定番茄酱中链霉素和双氢链霉素残留量的串联双柱净化-液相色谱-串联质谱方法。样品中的残留物用磷酸盐缓冲液(pH 4)提取,经分散固相萃取净化和串联双柱固相萃取净化后,用极性色谱柱在梯度洗脱条件下分离待测物,采用正离子电喷雾离子源(ESI+)在多反应监测(MRM)扫描模式下进行测定,外标法定量。链霉素和双氢链霉素在0.01～0.2 mg/L质量浓度范围内线性关系良好,相关系数(r)大于0.999。链霉素和双氢链霉素的定量限均为0.02 mg/kg,回收率为71%～101%,相对标准偏差为2.3%～15%。该方法操作简便,净化效果好,灵敏,准确,适用于检测和分析番茄酱及其制品中链霉素和双氢链霉素残留量。     

免疫亲和柱净化-高效液相色谱法同时检测鸡蛋中6种玉米赤霉醇类化合物残留量

建立了鸡蛋中6种玉米赤霉醇类化合物(α-玉米赤霉醇、β-玉米赤霉醇、α-玉米赤霉烯醇、β-玉米赤霉烯醇、玉米赤霉酮和玉米赤霉烯酮)残留量的免疫亲和柱净化-高效液相色谱检测方法。样品酶解后用叔丁基甲醚提取、氢氧化钠反萃取,经免疫亲和柱富集和净化后,采用高效液相色谱-紫外检测器进行测定。色谱柱: Agilent Eclipse XDB-C18(150 mm×4.6 mm, 3.5 μm);流动相: 甲醇-乙腈-水(50:15:35, v/v/v);流速: 1.0 mL/min;检测波长: 270 nm。结果表明,6种目标物在0.01～0.2 mg/L范围内线性关系良好,相关系数(r)≥0.9998,检出限(LOD,S/N≥3)为1.0 μg/kg,平均回收率为73.2%～95.7%,相对标准偏差小于8%。该方法灵敏度高、重现性好,适用于鸡蛋样品中痕量玉米赤霉醇类药物残留的测定。     

Determination of residual (free) monomer in water based polymer emulsions by head space gas chromatography mass spectrometry

A method for determination of residual acrylonitrile, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethyl hexyl acrylate, styrene and 2-methyl styrene monomers in polymer emulsions by head space gas chromatography mass spectrometry. Monomers were separated on DB-624 column and detected by MS under SIM (Selected ion monitoring) mode. The linear regression analysis data for the calibration curve for all monomers showed a good linear relationship with a regression coefficient of 0.99 over the concentration range of 5.3 mg/kg to 1172 mg/kg. The limit of detection and limit of quantification for the target analytes were in the range from 0.4 to 2.9 mg/kg and 0.9 to 7.3 mg/kg respectively.     

气相色谱法对水果样品中三碘苯甲酸残留的测定

分别选取了苹果、梨等6种水果基质,样品经1%硫酸酸化,用二氯甲烷提取,提取液蒸干后用三甲基硅重氮甲烷进行甲酯化衍生,经弗罗里硅土固相萃取柱净化后上机测定.采用气相色谱,程序升温,电子捕获检测器测定,保留时间定性,外标法定量.优化了衍生条件,并对方法的灵敏度、准确度、精密度和回收率进行了实验,三碘苯甲酸的检出限可达0.000 8 mg/kg,方法在0.01 ～20 mg/L范围内线性关系良好.各浓度水平的添加回收率为63% ～107%,相对标准偏差为1.8% ～9.3%.建立的方法符合国家标准对食品中农药残留测定的要求,可用于对食品安全的监测.     

固相萃取–气相色谱–串联质谱法测定茶叶中9种农药残留量

建立固相萃取净化–气相色谱–串联质谱法同时测定茶叶中9种农药残留量的方法。茶叶样品用乙腈均质提取,提取液经固相萃取净化处理后,采用DB–5MS毛细管色谱柱分离,在多反应监测模式下测定,外标法定量。9种农药组分的质量浓度在0.01~0.50 mg/L范围内与其色谱峰面积呈良好线性,相关系数r~2大于0.998,方法测定下限(10 S/N)为0.002~0.01 mg/kg。以空白绿茶、红茶、普洱茶和乌龙茶为基体,在0.05,0.1,0.2 mg/kg 3个添加水平进行加标回收试验,加标回收率在73.6%~99.7%之间,相对标准偏差为4.2%~8.7%(n=6)。该法操作简便、快速,适用于茶叶中多种农药残留的测定。     

超高效合相色谱法快速检测塑料食品接触材料中13种紫外吸收剂

建立了一种同时检测塑料食品接触材料中13种紫外吸收剂的超高效合相色谱法。以甲醇为溶剂对塑料食品接触材料样品进行超声提取，经C18固相萃取柱净化，过0.22 μm有机滤膜，采用超高效合相色谱仪分析。选择ACQUTY UPC² HSS C18 SB色谱柱（150 mm×3.0 mm，1.8 μm），以超临界二氧化碳为流动相，异丙醇为改性剂进行梯度洗脱，在最优色谱条件下，13种紫外吸收剂能够在4 min内实现有效分离。结果表明，在各自线性范围内，13种紫外吸收剂的线性关系良好，标准曲线相关系数不低于0.9985，检出限（S/N=3）为0.05~0.15 mg/kg，加标回收率为86.8%~115.7%，相对标准偏差为0.73%~5.61%。该方法快速简便，准确可靠，同时大大减少了有机溶剂的消耗，可用于塑料食品接触材料中13种紫外吸收剂的快速检测。     

液相色谱法测定番茄制品中链霉素和双氢链霉素的残留量

建立了测定番茄制品中链霉素和双氢链霉素残留量的净化方案.样品中的残留物用磷酸盐缓冲液(pH4)提取,经分散固相萃取法初步净化后,再经串联双柱固相萃取净化,用RPC18(Symmetry Shield)色谱柱在梯度洗脱下分离待测物,外标法定量.链霉素的线性范围为0.05～0.8 mg/L,相关系数r＞0.999 8.方法的回收率为71％～95％,定量限(S/N=10)为0.1 mg/kg,测定结果的相对标准偏差为2.6％～10.5％.该方法操作简便,净化效果好,灵敏、准确,检测成本低,适用于检测和分析番茄制品中链霉素和双氢链霉素的残留量.     

固相萃取-液相色谱-串联质谱法测定食品包装材料中16种全氟烷基类化合物

建立了使用固相萃取-液相色谱-串联质谱(SPE-LC-MS/MS)同时检测食品包装材料中16种全氟烷基类化合物(PFAS)的方法。分别对样品前处理方法、质谱条件等进行了比较和优化,样品用甲醇超声提取,经Oasis WAX固相萃取小柱净化后,用Atlantis T3 C₁₈色谱柱分离,以乙腈和5 mmol/L乙酸铵溶液为流动相进行梯度洗脱,多反应监测(MRM)负离子模式扫描,同位素内标法和外标法结合定量。16种PFAS在0.5~20.0 μg/L范围内线性关系良好,相关系数(r²)均大于0.99。加标回收率为68.6%~109.2%,RSD为2.5%~18.1%(n=6)。检出限为0.2~0.5 μg/kg,定量限为0.5~1.0 μg/kg。该方法简便、快速、准确,可用于食品包装材料样品中PFAS的检测。     

Enantioseparation and dissipation of acephate and its highly toxic metabolite methamidophos in pakchoi by supercritical fluid chromatography tandem mass spectrometry

Acephate is widely used in crops as racemate. However, the enantioselective dissipation of acephate enantiomers has not been investigated in pakchoi. A sensitive and effective approach was established for determining residues of acephate and its highly toxic metabolite methamidophos enantiomers by supercritical fluid chromatography tandem mass spectrometry. Baseline separations for their enantiomers were achieved by using a Chiralcel OD-H column. The optimal chromatographic conditions were obtained as follows: CO₂/ethanol (95/5) as mobile phase; flow rate, 3.0 mL/min; column temperature, 40°C. The mean recoveries (RSDs) of analytes were in the range of 77–83.1% (6.1–9.9%), 75.4–87.5% (9.3–13.2%), and 81.5–84.2% (7.1–13.4%) at three fortification levels (0.005, 0.05, and 0.5 mg/kg for each enantiomer) for interday assay (n = 18). The method was used to evaluate the enantioselective dissipation of acephate and methamidophos in pakchoi. S-acephate dissipated faster than R-acephate, while the concentration of R-methamidophos was higher than that of S-methamidophos during the entire study period. The results indicated that the R-enantiomer of acephate and methamidophos was preferentially enriched in pakchoi. The established analysis approach and the study data provided useful information for the rational use of acephate in agriculture.     

A simplified method for the determination of fenpropathrin residues in fruits

Summary A simple and efficient method is described for the determination of fenpropathrin in oranges, pears, apples and strawberries. The procedure is based on the extraction of each homogenized fruit sample with hexane:acetone (1∶1, v/v) mixture, followed by a cleanup technique on a column packed with florisil, using a hexane:ethyl ether (7∶3, v/v) mixture, and gas chromatographic analysis with electron capture detection (ECD). The fortification levels (0.5;1.0;2.0 mg kg⁻¹) were selected according to the maximum residue limits (MRLs) established for fenpropathrin by Brazilian legislation. Mean recoveries from five replicates of fortified fruit samples ranged from 83 % to 98%, with coefficients of variation from 1.4 to 13.5 and detection limits varying from 0.1 to 0.2 mg kg⁻¹.     

Enantioselective separation of the carfentrazone‐ethyl enantiomers in soil,water and wheat by HPLC

A simple enantioselective HPLC method was developed for measuring carfentrazone‐ethyl enantiomers. The separation and determination was accomplished on an amylose tris[(S)‐α‐methylbenzylcarbamate] (Chiralpak AS) column using n‐hexane/ethanol (98:2, v/v) as mobile phase at a flow rate of 1.0 mL/min with UV detection at 248 nm. The effects of mobile‐phase composition and column temperature on the enantioseparation were discussed. The accuracy, precision, linearity, LODs, and LOQ of the method were also investigated. LOD was 0.001 mg/kg in water, 0.015 mg/kg in soil and wheat, with an LOQ of 0.0025 mg/kg in water and 0.05 mg/kg in soil and wheat for each enantiomer of carfentrazone‐ethyl. SPE was used for the enrichment and cleanup of soil, water, and wheat samples. Recoveries for two enantiomers were 88.4–106.7% with RSD_r of 4.2–9.8% at 0.1, 0.5, and 1 mg/kg levels from soil, 85.8–99.5% with the RSD_r of 4.4?9.6% at 0.005, 0.025, and 0.05 mg/kg levels from water, and from wheat the recoveries were 86.3?91.3% with RSD_r below 5.0% at 0.2, 0.5, and 1 mg/kg levels. This method could be used to identify and quantify the carfentrazone‐ethyl enantiomers in food and environment.     

Determination of pyrethroid pesticide residues in processed fruits and vegetables by gas chromatography with electron capture and mass spectrometric detection

A gas chromatographic method was developed for the simultaneous determination of 12 pyrethroids (tefluthrin, bifenthrin, fenpropathrin, cyhalothrin, permethrin, cyfluthrin, cypermethrin, alpha-cypermethrin, flucythrinate, fenvalerate, fluvalinate, and deltamethrin) in tomato puree, peach nectar, orange juice, and canned peas. A miniaturized extraction-partition procedure requiring small amounts of nonchlorinated solvents is used. Samples are extracted with acetone, partitioned with ethyl acetate-cyclohexane (50 + 50, v/v), and cleaned up on a Florisil cartridge. The final extract is analyzed by gas chromatography with both electron capture and mass spectrometric detection modes. Studies at fortification levels of 0.010-0.100 mg/kg gave mean recoveries ranging from 70.2 to 96.0% and coefficients of variation between 4.0 and 13.9% for all compounds. Quantitation limits were < 0.010 mg/kg for electron capture detection.