亲水作用色谱-串联质谱法测定稻米中的草甘膦和氨甲基磷酸残留量

采用亲水作用色谱-串联质谱建立了同时测定稻米中草甘膦及其主要代谢物氨甲基磷酸残留量的检测方法。样品经水提取,C18固相萃取柱和超滤膜净化,以1 mmol/L乙酸铵溶液(用氨水调pH=11.0)-乙腈为流动相,亲水作用色谱柱分离,采用电喷雾离子源、负离子扫描模式和多反应监测模式质谱检测,基质匹配标准溶液外标法定量。草甘膦和氨甲基磷酸分别在0.001～0.250 mg/L和0.0025～0.250 mg/L质量浓度范围内线性关系良好,检出限(信噪比为3)分别为0.010 mg/kg和0.020 mg/kg。通过对空白大米样品进行0.100、0.500和2.500 mg/kg 3个加标水平的回收试验,草甘膦和氨甲基磷酸的平均回收率和相对标准偏差分别为96.3%～107.3%和1.3%～9.1%(n=3)。该方法无需衍生,净化步骤简便快速,定量准确,可满足稻米中草甘膦和氨甲基磷酸残留检测要求。     

气相色谱结合分光光度计测定尿素醇解合成碳酸二甲酯产物

采用GDX-203色谱柱,热导检测器,异丁醇为内标,分析测定了尿素与甲醇合成碳酸二甲酯产出物中的原料甲醇(Me),产物碳酸二甲酯(DMC),氨基甲酸甲酯(MC),N-甲基氨基甲酸甲酯(NMMC)的含量.用对二甲氨基苯甲醛(PDAB)作显色剂,总吸光度差减去氨基甲酸甲酯吸光度后,测定产物中少量的尿素(Urea).分析的相对标准偏差低于3.5%,回收率在97%～103%.     

气相色谱-质谱联用法同时测定乳及乳制品中的三聚氰胺及肌酐

建立了同时测定乳制品中三聚氰胺及肌酐的气相色谱-质谱联用方法。样品经1%三氯乙酸溶液萃取,混合型阳离子交换固相萃取净化,提取液用氮气吹干后加入N,O-双(三甲基硅基)三氟乙酰胺-三甲基氯硅烷(BSTFA-TMCS)硅烷化试剂,于75 ℃下衍生60 min,最后采用选择离子模式下的气相色谱-质谱测定。三聚氰胺和肌酐的定量限分别为0.10 mg/kg和0.20 mg/kg;在0.1～50 mg/L范围内的线性相关系数均大于0.99。实际样品中,肌酐在10～100 mg/kg和三聚氰胺在0.1～5.0 mg/kg添加范围内的回收率分别为80.7%～116.8%和77.6%～107.5%,相对标准偏差分别小于9.4%和8.5%。该方法能有效除去干扰,灵敏度高,回收率较好,可用于乳制品中三聚氰胺和肌酐的同时测定。     

气相色谱-质谱法测定香水中的甲基丁香酚

建立了气相色谱-质谱法测定香水中甲基丁香酚的分析方法。该方法在0.01～1.00 mg/L范围内线性关系良好。香水样品平均加标回收率为100.1%～102.9%,相对标准偏差为0.08%～1.7%,方法检出限为0.50 mg/kg。     

反反相色谱-串联质谱法直接测定植物源性食品中草甘膦及其代谢物残留

采用反反相色谱-串联质谱法建立了直接测定植物源性食品中草甘膦(GLY)及其主要代谢物氨甲基膦酸(AMPA)的方法。样品用水提取,阴离子交换柱(MAX)净化,以5 mmol/L的乙酸铵溶液和5%水-95%乙腈的乙酸铵溶液为流动相,反反相色谱分离,采用电喷雾离子源、负离子扫描模式和多反应监测模式质谱检测,外标法定量。草甘膦和氨甲基膦酸的线性范围分别为10～500μg/L和20～1 000μg/L,相关系数(r2)均大于0.99。方法的检出限(S/N=3)均为0.01 mg/kg,定量下限(S/N=10)分别为0.02 mg/kg和0.04 mg/kg。在6种基质中,GLY和AMPA在3个加标水平下的回收率为78%～113%,相对标准偏差(RSD,n=6)为3.2%～11.0%。方法的灵敏度和回收率高,选择性好,能满足日常食品检测工作的要求。     

高效液相色谱法测定覆铜板粘结片中的N,N-二甲基乙酰胺残余量

建立高效液相色谱法检测覆铜板粘结片中N,N-二甲基乙酰胺残余量的方法。以甲醇溶液萃取覆铜板粘结片中的N,N-二甲基乙酰胺,高效液相色谱法测定N,N-二甲基乙酰胺的含量。试验并确定了最佳色谱条件。在选定条件下,N,N-二甲基乙酰胺含量在0.05~300 mg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数为0.999 95,检出限为0.6 mg/kg,加标回收率为101.0%~107.8%,测定结果的相对标准偏差小于10%(n=6)。该方法准确、快速,可用于覆铜板生产的质量控制。     

气相色谱-串联质谱法快速测定调味品中3种糠醛类物质

建立了同时测定调味品中糠醛、5-甲基糠醛和5-羟甲基糠醛的气相色谱-串联质谱法(GC-MS/MS)。对样品的前处理方法及GC-MS/MS分析条件进行优化,样品经乙酸乙酯萃取,GC-MS/MS多反应监测模式(MRM)进行测定。3种糠醛类物质在0.001～20 mg/L范围内均呈良好的线性关系,相关系数为0.999 0～0.999 5;检出限(S/N=3)均为0.005 mg/kg,加标回收率为86%～95%。该法简便、快速、溶剂用量少,可消除调味品中复杂基质的干扰,结果准确可靠、灵敏度高,适用于调味品中3种糠醛类物质的同时测定。     

液相色谱-串联质谱法测定饮料中邻苯二甲酸二(2-乙基)己酯和邻苯二甲酸二异壬酯

建立了饮料中邻苯二甲酸二(2-乙基)己酯(DEHP)和邻苯二甲酸二异壬酯(DINP)残留的液相色谱-串联质谱(LC-MS/MS)检测方法。2.0 g样品经8 mL甲醇振荡提取、定容、离心,取上清液过滤,采用LC-MS/MS电喷雾电离,多反应监测(MRM)模式对样品进行分析。DEHP在浓度范围为2～200μg/L,DINP在10～1000μg/L内线性良好,相关系数均大于0.998。实验表明:样品无明显的基质效应。样品中添加0.01～5 mg/kg的DEHP和DINP,其回收率为86.2%～111.6%;相对标准偏差(n=6)小于11%;DEHP检出限为0.008 mg/kg,定量限为0.01 mg/kg;DINP检出限为0.01 mg/kg,定量限为0.05 mg/kg。本方法提取效果好,具有良好的灵敏度、回收率和重复性,被成功用于实际饮料样品中DEHP和DINP的测定。     

柱后衍生液相色谱法测定粮食中草甘膦和氨甲基磷酸残留量

建立了固相萃取-高效液相色谱(HPLC)柱后衍生荧光检测粮食中草甘膦(GLY)和氨甲基磷酸(AMPA)残留的测定方法.样品中分析物用水提取,强阳离子柱(SCX)净化,钾离子交换柱分离,柱后采用次氯酸钠(NaClO)和邻苯二甲醛(OPA)、巯基乙胺衍生化,最终为荧光检测器(FLD)所分析.草甘膦和氨甲基磷酸在0～20 mg/L范围内线性良好,相关系数达0.9966和0.9999;在精米和小麦粉1、5、10 mg/kg 3个添标水平上,平均回收率(重复3次)在83.2%～119.1%之间;7次测量精密度分别为2.86%和4.86%;样品稀释22.22倍,方法的检出限为0.5 mg/kg.     

高效液相色谱-串联质谱法检测茶叶中痕量草胺膦、草甘膦及其代谢物氨甲基膦酸残留

建立高效液相色谱–串联质谱法测定茶叶中除草剂草胺膦、草甘膦及其代谢物氨甲基膦酸残留的方法。以纯水提取茶叶中的草胺膦、草甘膦、氨甲基膦酸,用二氯甲烷、阴离子交换固相萃取柱净化、富集,以0.25 mol/L碳酸氢钠溶液洗脱,然后直接采用1%芴甲氧羰酰氯进行衍生,衍生时间为5 min,用反相液相色谱柱分离,以电喷雾正离子模式,多反应模式(MRM)检测。草胺膦、草甘膦、氨甲基膦酸的质量浓度在0～20μg/L范围内均具有良好的线性,线性相关系数大于0.995,方法定量限为0.01 mg/kg。在不同茶叶基质中,0.01,0.025,0.05 mg/kg三水平的平均添加回收率为94.0%～116.0%,测定结果的相对标准偏差为3.5%～7.1%(n=6)。该方法操作简便,灵敏度与准确度高,满足茶叶样品中草胺膦、草甘膦及其代谢物氨甲基膦酸低残留的检测要求。     

离子色谱法检测食品添加剂焦碳酸二甲酯中的氯离子

建立离子色谱法检测食品添加剂焦碳酸二甲酯（DMDC）中的杂质氯离子的方法。样品用水溶解超声定容后,采用SH-AC-1阴离子交换柱（250mm×4．6mm,5μm）分离,抑制电导法检测。考察了淋洗液种类、浓度对氯离子与干扰离子分离度的影响。最佳色谱条件：以0．005mol／L的四硼酸钠水溶液为淋洗液,流速1．0mL／min。在此条件下,样品中的氯离子可以和其它干扰离子分离,而且分离度达3．0以上,峰形对称。在氯离子浓度为0．1～5．0mg／L的范围内,可获得良好的线性关系,线性相关系数大于0．999;氯离子检出限（S／N=3）达0．007mg／L,加标回收率为97．5％～98．9％。该方法可以用于食品添加剂DMDC中氯离子的测定。     

离子色谱法检测高纯硅微粉中痕量铁和氧化铁杂质

建立了柱后衍生-紫外检测-离子色谱法同时测定高纯硅微粉中痕量铁和氧化铁杂质含量的方法。方法选用具有阴阳离子交换基团的高选择性Thermo Scientific Dionex^TM IonPac^TM CS5A色谱柱,选择与铁形成单一络合形态、中等络合能力的2,6-吡啶二羧酸（PDCA）为淋洗液,在线柱后添加普适性的4-2-吡啶偶氮苯二酚（PAR）金属显色剂,于530 nm波长下准确完成了二价和三价铁离子的分离测定。结果表明,本方法对二价铁离子和三价铁离子的检出限分别为0.013 mg/kg和0.006 mg/kg,线性相关系数r²均大于0.999,实际样品中二价铁和三价铁的加标回收率分别为79%~90%和92%~105%,具有较高的灵敏度、准确度和选择性。该方法可以准确测定高纯硅微粉中痕量二价铁和三价铁的含量,以此结果反馈高纯硅微粉产品中铁杂质含量的不同来源,为其生产工艺的持续优化和改进提供重要的参考数据。     

花生及其制品中多种霉菌毒素残留同时测定方法

利用液相色谱-质谱联用（LC-MS／MS）建立了花生及其制品中多种霉菌毒素包括黄曲霉毒素（B1,B2,G1,G2）、赭曲霉毒素A、伏马毒素B1、脱氧雪腐镰刀菌烯醇、T-2毒素、HT-2毒素及玉米赤霉烯酮的同时测定方法。样品经PBS溶液和甲醇-水溶液提取,提取液经稀释、过滤后,用免疫亲和柱净化,通过淋洗去除免疫亲和柱上的杂质,随后用洗脱液过柱,将目标物分离下来,氮吹干后定容。以液相色谱-质谱／质谱测定,外标法定量。方法的检出限黄曲霉毒素B1为0．0005mg／kg,黄曲霉毒素B2,G1,G2为0．001mg／kg,赭曲霉毒素A为0．002mg／kg,伏马毒素B1为0．020mg／kg,脱氧雪腐镰刀菌烯醇为0．050mg／kg,T-2毒素为0．010mg／kg,HT-2毒素为0．010mg／kg,玉米赤霉烯酮为0．002mg／kg。在样品中添加检出限水平的毒素混标溶液,加标回收率为72．35％-97．82％,测定结果的相对标准偏差为8．95％～18．41％（n=10）.     

高效液相色谱柱后衍生测定脱水蔬菜中的亚硫酸盐

建立了检测脱水蔬菜中亚硫酸盐的反相硅胶柱净化-柱后衍生-高效液相色谱方法.样品经甲醛提取,通过反相硅胶固相萃取小柱净化,采用Discover ODS-C18柱,流动相为0.005 mol/L氢氧化四丁基铵和乙腈,在碱性条件下以5,5’-二硫代双(2-硝基苯甲酸)为柱后衍生化试剂,445 nm检测.实验结果表明,在0.050～50.00 mg/L浓度范围内,相关系数为0.9987,方法的检出限和定量限分别为1 mg/kg和2 mg/kg,添加浓度在2～900mg/kg范围内,平均添加回收率为62％～88％,相对标准偏差不大于7.8％.该法能有效地避免脱水蔬菜中亚硫酸盐测定的假阳性结果,可满足实际检测工作的需要.     

Method of fast trace microanalysis of the chiral pesticides epoxiconazole and novaluron in soil samples using off-line flow-through extraction and on-column direct large volume injection in reversed-phase high performance liquid chromatography

An analytical method combining off-line flow-through extraction of a soil micro-sample (mass around 100 mg, packed into a short HPLC glass column) and direct on-column large-volume injection (LVI up to 1.00 mL) of a methanol-water soil extract onto a conventional C18 RP HPLC column enabled fast (within 3.5 minutes) trace micro-analysis of the relatively new chiral pesticides epoxiconazole (E) and novaluron (N), respectively. Linear calibration curves were evaluated from UV detection (230 nm) data in the range from 0.1 to 5 mg/kg in three most abundant Slovak agricultural soils. LOD (confidence band) at the levels 0.08-0.11 mg/kg and LOQ 0.4-0.6 mg/kg and LOD (S/N = 3) at the levels 0.007-0.018 mg/kg and LOQ (S/N = 10) 0.024-0.060 mg/kg, respectively, of dry soil were achieved. Recovery of pesticides in the overall LVI method including flow-through 130-200 mg soil micro-sample extraction was: for epoxiconazole from 74 to 85% and from 56% to 90% for novaluron with reproducibility within +/- 6% RSD. This fast (30 min) and simple method consists of just three steps which are short column filling with a solid micro-sample; flow-through liquid extraction and direct large-volume injection RP HPLC DAD analysis. The method is prepared for automation and further analysis of enantiomers of both investigated pesticides by achiral-chiral column switching techniques.     

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.     

改进的QuEchERS-串联质谱法测定莴苣中的124种农药残留

通过比较d-SPE(PSA+GCB)、SPE(NH2-Carb柱)和SPE(GCB/PSA柱)3种前处理方法的净化效果及方法稳定性,选取了GCB/PSA柱固相萃取作为净化方法。样品经前处理后,采用大体积进样,气相色谱-串联质谱测定,内标法定量。124种农药在浓度为0.010～0.200 mg/kg范围内与峰面积呈线性关系,相关系数均大于0.9800,以10倍信噪比计算,定量限在0.1～19.0μg/kg之间。当农药在样品中添加水平为0.040 mg/kg时,124种农药平均回收率(n=5)为80.0～130.7%,RSD为1.1～2.0%。     

An internal surface reversed phase column for the effective removal of humic acid interferences in the trace analysis of mecoprop in soils with coupled-column RPLC-UV

In the development of a screening method for the determination of residues of mecoprop in soils involving coupled-column RPLC-UV (228 nm) the cleanup performance of a 5 μm GFF-II internal surface reversed phase (ISRP, Pinkerton) analytical column (50 × 4.6 mm I.D.) as a first column was investigated. In comparison to an analytical C18 column the ISRP column substantially improved the separation between acidic analyte and co-extracted humic substances. Under the selected coupled-column conditions soil extracts obtained after hydrolysis with an aqueous alkaline solution, acidifying and centrifugation could be analyzed directly allowing the determination of mecoprop in soils to a level of about 0.02 mg/kg. A rapid concentration step on a 100 mg C18 solid phase extraction (SPE) cartridge was adopted into the procedure providing a limit of detection (S/N = 3) of 0.01 mg/kg of mecoprop in soil. The method was validated by analyzing freshly spiked soil samples and samples with aged residues. In case of freshly spiked samples the overall recovery was 87% (n = 18, spiked level 0.02–8.0 mg/kg) with a repeatability of 6.8% and a reproducibility of 8.3%. No significant decrease of the recovery was observed for samples with aged residues (n = 15, spiked level 0.1 and 8.0 mg/kg) during a storage of 29 days in the refrigerator at about 4?°C; a storage of 67 days provided a mean recovery of 76% (n = 14, spiked level 8.0 mg/kg).     

A new method research for determination of natural pigment crocin yellow in foods by solid-phase extraction ultrahigh pressure liquid chromatography

Crocin yellow was determined in soft drinks, sausages and sauces by ultra performance liquid chromatography coupled with ultraviolet detector and analyzed within 5 min using a short analytical column ACQUITY UPLC HSS T3 2.1 x 100 mm 1.8 μm) with gradient elution. An innovative pretreatment method based on homemade macroporous resin solid-phase extraction (SPE) column was established. The SPE column packed with macroporous resins could simplify the sample preparation of multi-matrices and be reused by regeneration steps. The recoveries of crocin yellow added to soft drinks, sausages and sauces at three levels ranged from 81.3% to 106.2%, and relative standard deviations (RSDs) were within 8.8%. The limits of quantitation of soft drinks, sausages and sauces were 0.5 mg/kg, 5 mg/kg and 5 mg/kg, respectively.     

气相色谱-质谱法测定茶叶中29种酸性除草剂的残留量

建立了茶叶中29种酸性除草剂残留量的气相色谱-质谱测定与确证方法。采用乙腈超声振荡提取试样中29种酸性除草剂,石墨化炭黑固相萃取柱净化,三甲基硅烷化重氮甲烷衍生化,再经弗罗里硅土固相萃取柱净化,用气相色谱-质谱法选择离子监测方式测定,外标法定量,根据离子丰度比确证。在加标水平为0.01,0.05,0.1 mg/kg时,29种目标物的加标回收率为57.1%～120.4%,相对标准偏差(RSD)为4.3%～20.9%;方法的检出限在0.002～0.005 mg/kg之间。该方法准确、灵敏、快速,可满足国际上对茶叶中29种酸性除草剂残留的检测需要。