液相色谱-串联质谱法测定液态乳制品中的苯代三聚氰胺

建立了液态乳制品中苯代三聚氰胺的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法。优化了前处理条件、液相色谱和质谱参数。样品经LC-C18固相萃取柱富集净化后,采用ZORBAX-Eclipse Plus C18色谱柱分离,流动相为乙腈-水(15∶85,体积比),流速为0.3 mL/min。采用正离子模式的电喷雾质谱检测,多反应(MRM)选择离子监测,定量离子与定性离子分别为m/z 104.1与m/z 146.0,外标法定量。结果表明,苯代三聚氰胺在2~100 μg/L范围内线性关系良好,相关系数为0.999 1,方法的检出限和定量下限分别为1.0 μg/kg和3.0 μg/kg。在低、中、高3个加标水平下的平均回收率为77%~105%,相对标准偏差(RSD)为2.3%~5.0%。该方法操作简单、准确可靠,适用于液态乳制品中苯代三聚氰胺的测定。     

高效液相色谱-质谱法对饲料及食品添加剂中三聚氰胺的测定

建立了饲料中三聚氰胺的高效液相色谱-质谱测定方法.色谱条件:Kromasil C18柱(4.6 mm×250mm,5 μm),流动相:乙腈-0.1%(体积分数)甲酸(体积比5:95),流速0.4 mL/min.采用正离子模式的电喷雾质谱检测,以一级质谱得到的准分子离子m/z 127作为母离子,进行碰撞诱导解离(CID)二级质谱(MS2)分析,选择母离子和MS2的碎片离子m/z 85、109定性确证,提取m/z 85、109、127三个离子质量色谱峰面积定量.实验优化了质谱条件.线性范围为0.01～0.5 mg/L,检出限0.01 mg/L(S/N=3),回收率为80%～99%.     

超高效液相色谱-串联质谱法测定乳制品中三聚氰胺的残留量

建立一种用超高效液相色谱-电喷雾质谱联用技术测定乳制品中三聚氰胺残留量的方法.样品经含5%乙酸铅的三氯乙酸溶液提取,离心分离后经PCX-C18混合填料固相萃取柱净化.色谱分离采用Agilent ZORBAX-CN柱(250 mm×4.6 mm i.d.,5 μm),以10 mmol/L V(乙酸铵)∶V(乙腈)＝10∶90混合溶液为流动相.采用电喷雾离子源,正离子多反应监测(MRM)模式检测.该方法在1～1000 ng/mL范围内线性关系良好.在添加水平为10,30,45 μg/kg时,回收率在78.5%～92.6%之间,相对标准偏差在3.5%～8.6%之间,检出限为10 μg/kg.该方法适合于乳制品中三聚氰胺残留量的检测.     

超高效液相色谱-串联质谱法测定水产品中三聚氰胺残留量

建立超高效液相色谱-串联质谱(UPLC-MS/MS)快速测定水产品中三聚氰胺残留的方法.采用ACQUITY UPLC BEH HILIC色谱柱(100 mm×2.1 mm, 1.7 μm),流动相为乙腈-0.5 mmol/L乙酸铵溶液(0.1%甲酸),流速为0.3 mL/min.采用电喷雾质谱检测,以正离子模式5 min完成质谱分析.实验结果表明,三聚氰胺在水产品中的检测限为0.05 mg/kg,在0.05～0.50 mg/kg添加水平时的加标回收率为63%～90%,测定结果的相对标准偏差均小于7.2%(n=6).     

奶粉中高氯酸盐的液相色谱-串联质谱测定

建立了奶粉中高氯酸盐的液相色谱-串联质谱(LC-MS/MS)测定方法.奶粉样品用水-乙腈(体积比1:2)超声波振荡提取2次,于4 000 r/min离心后,上清液经Oasis HLB固相萃取小柱净化;采用离子交换色谱分离,色谱柱为METROSEP A Supp 5(150 mm×4.0 mm)阴离子交换柱,流动相为0.2 mol/L乙酸铵溶液-乙腈(体积比1 : 1),流速0.7 mL/min;电喷雾负离子模式电离,质谱多反应选择离子检测(MRM),检测离子对为 m/z 99→83和m/z 101→85,其中m/z 99→83为定量离子对.方法的相对标准偏差为3.59%,回收率为91% ～106%,检出限为1.0 μg/kg,定量下限为5.0 μg/kg.结果表明,该法简便快速、准确可靠,也适用于鲜牛奶、酸牛奶等其他乳制品中高氯酸盐的测定.     

电喷雾萃取电离质谱法检测1-羟基芘

采用电喷雾萃取电离质谱(EESI-MS)分析致癌性环境有机污染物多环芳烃(PAHs)生物标志物1-羟基芘(1-OHP),探究1-OHP在EESI源中电离的可行性,考察ESI溶剂和样品溶液组成对方法灵敏度的影响,初步建立I-OHP的EESI MS半定量分析方法.结果表明,溶液中1-OHP能够在EES1源中有效电离,生成准分子离子[M-H]- (m/z 217),并得到其二级质谱特征碎片离子[M- H- CO]- (m/z 189);水、甲醇、乙醇、正丙醇和正丁醇5种ESI溶剂中,使用甲醇时,离子峰m/z 217信噪比最大.样品溶液中甲醇含量越高,离子峰m/z 217强度越强.离子峰m/z 217强度与1-OHP浓度在10～200 μg/L内的线性相关性相对最好;相关系数(R)0.982;相对标准偏差(RSD)为3.4％～14.0％(n=5);定量下限约为10 μg/L(S/N=10);单次检测时间小于0.5 min.     

液相色谱-质谱法对饮用水中六价铬的测定

建立了液相色谱分离、电喷雾质谱测定饮用水中六价铬的方法.水样经微孔滤膜过滤后直接进样,以乙腈-1.5 mmol/L四丁基氢氧化铵水溶液为流动相,Xterra~(TM) MS C_(18)色谱柱分离六价铬,使用单四极杆质谱,选择离子模式检测,监测离子为m/z 118、117、101、85,其中117为定量离子.Cr(Ⅵ)的线性范围为1.0 ～100.0 μg/L,方法定量下限为1 μg/L.在空白水样中分别添加1.0、2.0、10.0 μg/L的六价铬,测得平均回收率(n=5)依次为91%、94%、97%,相对标准偏差分别为12.2%、7.4%、3.5%.测定了42个饮用水样品,其中17批检出六价铬,检出量为1.2 ～15.4 μg/L.     

超高效液相色谱-电喷雾串联质谱法对饲料中匹莫林的测定

建立了超高效液相色谱-串联质谱测定饲料中匹莫林的方法.饲料样品经甲醇-乙腈溶液提取,取部分上清液氮气吹干,用甲醇和水分步溶解后用正己烷除脂,Waters Oasis HLB固相萃取小柱净化,然后用Waters Acquity UPLC BEH C18色谱柱(2.1 mm×50 mm i.d.,1.7 μm)分离,以甲醇和0.1%甲酸-水溶液为流动相进行梯度洗脱,外标法定量.对前处理及液相色谱和质谱条件进行优化.结果表明,匹莫林质量浓度在1 ～500 μg/L范围内线性良好,相关系数大于0.999;在5.0 ～200 μg/kg的添加水平下,匹莫林的平均加标回收率为77% ～86%;相对标准偏差为4.4% ～7.9%;方法的检出限低至2.0 μg/kg,定量下限低至5.0 μg/kg.该方法灵敏度高、稳定性好,可满足饲料中匹莫林残留的检测与确证的要求.     

液相色谱-串联质谱法测定液态乳制品中的苯代三聚氰胺

建立了液态乳制品中苯代三聚氰胺的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法。优化了前处理条件、液相色谱和质谱参数。样品经LC-C18固相萃取柱富集净化后,采用ZORBAX Eclipse Plus C18色谱柱分离,流动相为乙腈-水(15∶85,体积比),流速为0.3 mL/min。采用正离子模式的电喷雾质谱检测,多反应(MRM)选择离子监测,定量离子与定性离子分别为m/z 104.1与m/z 146.0,外标法定量。结果表明,苯代三聚氰胺在2~100μg/L范围内线性关系良好,相关系数为0.999 1,方法的检出限和定量下限分别为1.0μg/kg和3.0μg/kg。在低、中、高3个加标水平下的平均回收率为77%~105%,相对标准偏差(RSD)为2.3%~5.0%。该方法操作简单、准确可靠,适用于液态乳制品中苯代三聚氰胺的测定。     

SPE-LC-MS联用同时测定环境水样中痕量三聚氰胺和灭蝇胺

建立了一种同时测定环境水样中痕量三聚氰胺和灭蝇胺的固相萃取-高效液相色谱-质谱联用(SPE-LC-MS)分析方法。水样经PCX柱固相萃取,以CN柱为分析柱,V(甲醇)∶V(水)=30∶70为流动相,采用电喷雾正离子模式全扫描,三聚氰胺、灭蝇胺的定量离子分别为m/z127,m/z167,获得的最低检出限分别为0.05,0.08μg/L,对不同来源的实际水样加标回收率为85.2%～104.2%,相对标准偏差为1.5%～5.1%。应用该方法测定了湖水、河水、江水等不同基质实际水样。     

衍生化-离子阱气相色谱质谱联用检测乳粉中三聚氰胺时不同质谱检测方法研究

利用N,O-双三甲基硅基三氟乙酰胺(BSTFA)和三甲基氯硅烷(TMCS)衍生化试剂对乳粉中三聚氰胺进行衍生化处理,利用离子阱气相色谱质谱联用仪,建立了全扫描、选择离子监测、二级质谱3种测定三聚氰胺的质谱方法.选择离子监测以三聚氰胺衍生物的特征离子m/z342,327,171,99为定性离子,以m/z327为定量离子;全扫描法二级质谱特征峰为定性依据,以特征离子m/z327为定量离子;二级质谱法以衍生物二级质谱m/z285,171,213为定性离子,以m/z 285为定量离子.3种方法的线性范围为0.05～2.0 mg/L,线性相关系数分别为0.9986、0.9990、0.9988;检测限分别为0.005、0.002、0.003 mg/kg,RSD分别为6.3%、5.7%、6.1%(n=6),方法的回收率为84%～105%.3种不同质谱检测方法应用到乳粉的检测中效果良好,均能够满足乳粉中三聚氰胺的检测要求.     

亲水作用色谱-电喷雾串联质谱法检测原料奶及奶制品中的三聚氰胺

建立了亲水作用色谱-电喷雾串联质谱测定原料奶及奶制品中三聚氰胺的方法。样品采用1%三氯乙酸水溶液-乙腈（体积比为1∶1）混合溶液提取,混合型阳离子交换反相固相萃取柱（MCX）富集净化,亲水作用色谱柱分离,电喷雾串联四极杆质谱仪进行检测。结果表明,三聚氰胺的质量浓度在0.05～10.0 mg/L范围内具有良好的线性关系。原料奶及奶制品中的三聚氰胺在0.5,2.5和10 mg/kg 3个添加水平下,平均回收率为76.3%～98.7%,相对标准偏差均小于6.8%;定量限（S/N＞10）为0.05 mg/kg。     

气相色谱-质谱法测定乳制品中光引发剂异丙基硫杂蒽酮的残留量

建立了采用气相色谱（GC）-质谱(MS)检测由包装材料迁移到乳制品中的光引发剂异丙基硫杂蒽酮残留量的方法。使用氘代蒽为内标,样品经Carrez试剂除蛋白质后用丙酮-正己烷(体积比为1∶1)提取,上层提取液用氟罗里硅土固相萃取小柱净化。采用单四极杆质谱进行样品筛选和定量,选取的监测离子为m/z 184,m/z 224,m/z 239,m/z 254(异丙基硫杂蒽酮)和m/z 80,m/z 94,m/z 188,m/z 160(氘代蒽)。疑似样品采用离子阱串联质谱法进行确证,选取的母离子和子离子分别为m/z 254,m/z 239(异丙基硫杂蒽酮)和m/z 188,m/z 160(氘代蒽)。本方法的测定低限(LOQ)分别为7.0 μg/L(GC-MS)和5.0 μg/L(GC-MS/MS),回收率为74.9%~89.6%。采用该方法对11种不同类型的乳制品进行了检测,发现了两例阳性样品。     

Liquid chromatographic determination of honokiol and magnolol in hou po (Magnolia officinalis) as the raw herb and dried aqueous extract

A validated analytical method is described for the determination of honokiol and magnolol in Hou Po (Magnolia officinalis) as the dried raw herb and the commercially prepared dried aqueous extract. The samples were extracted with methanol by the Soxhlet method, and the extract was analyzed by liquid chromatography with photodiode array (LC/PDA) detection with confirmation of analyte identity by negative-ion electrospray ionization tandem mass spectrometry (ESI-MS/MS). A C18 column was used with a menthanol--0.1% aqueous acetic acid gradient mobile phase. Honokiol and magnolol were quantified at 288 nm. With the MS detector, the honokiol precursor ion at m/z 265 was shown to produce ions at m/z 222 and 224. For magnolol, the precursor ion at m/z 265 produced the ions at m/z 247 and 245. Comparable results were obtained for the LC/PDA and LC/ESI-MS/MS methods of quantitation. Six commercially prepared dried aqueous extracts were analyzed. The levels of honokiol and magnolol found in the raw herb were 17.0 and 21.3 mg/g, respectively. The limits of detection for honokiol and magnolol in the raw herb were 0.45 and 0.58 mg/g, respectively, and in the dried aqueous extract, 0.04 and 0.30 mg/g, respectively.     

Determination of trace level of perchlorate in Antarctic snow and ice by ion chromatography coupled with tandem mass spectrometry using an automated sample on-line preconcentration method

A new ion chromatography coupled with tandem mass spectrometry（IC-ESI-MS/MS） method,with automated sampling and on-line preconcentration,has been developed for the determination of perchlorate in Antarctic snow and ice at low part-per-trillion（ng/L） levels.To the best of our knowledge, this is the first time that an analytical method is used for the determination of perchlorate in Antarctic snow and ice.The IC-ESI-MS/MS instrumentation consisted of an ICS2000 ion chromatography（IC） system coupled to an API3200 electrospray tandem mass spectrometer（ESI-MS/MS）.On-line preconcentration was realized through a six-port injector valve,a TAC-ULP1 concentrator column and an AS auto-sampler.Multiple reaction monitoring（MRM） mode was used to quantify the perchlorate anion.The transition of ³⁵Cl¹⁶O₄^-（m/z 98.9） into ³⁵Cl¹⁶O₃^-（m/z 82.9） was monitored for quantifying the main analyte,and the transition of ³⁷Cl¹⁶O₄^-（m/z 100.9） into ³⁷Cl¹⁶O₃^-（m/z 84.9） was monitored for examining a proper isotopic abundance ratio of ³⁵Cl to ³⁷Cl,which was used as a confirmation tool.The limit of detection（LOD） and limit of quantitation（LOQ） for the method was 0.2 ng/ L and 0.5 ng/L,respectively.And this new method exhibited acceptable accuracy and precision for samples at ng/L levels.All the tested snow and ice samples were found to contain measurable amount of perchlorate,ranging from 10 ng/L to 340 ng/L.     

气相色谱-质谱法测定水中痕量的四乙基铅

建立了气相色谱-质谱(GC-MS)测定水中痕量四乙基铅的分析方法。用正己烷萃取水样中的四乙基铅,萃取液浓缩后加入同位素内标萘-d8,采用GC-MS选择离子方式(SIM)进行检测,在200 mL水样中四乙基铅的检出限可达0.04 μg/L;添加回收率为92.2%～103%,准确度好;平行5次测定的相对标准差为4.4%～13.3%。结果表明: 方法简便、快速、准确、实用,可用于水中痕量四乙基铅的测定。     

Liquid chromatography/tandem mass spectrometry analysis of chloramphenicol in cooked crab meat

A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method is described for the extraction, cleanup, determination, and confirmation of chloramphenicol (CAP) in cooked crab meat. The method involves pulverization of cooked crab meat with dry ice; extraction of the CAP into ethyl acetate (EtOAc); evaporation (by N2) of the EtOAc; addition of methanol, aqueous NaCl, and heptane; extraction of the lipids into the heptane, followed by extraction of the aqueous phase with EtOAc; evaporation (by N2) of the EtOAc; dissolution into methanol-water; filtration; and separation/detection/confirmation using LC/MS/MS. Crab meat was fortified at 0.25, 0.50, and 1.0 ng/g (ppb) chloramphenicol. Average absolute recoveries were 67, 84, and 86%, respectively, with relative standard deviation values all less than 1%. Four daughter ions (m/z 152, 176, 194, and 257) were monitored off the m/z 321 precursor ion. Determination was based on a standard curve using the peak areas of the m/z 152 daughter ion (the base peak) for standard solutions equivalent to 0.10, 0.20, 0.50, and 1.0 ppb in tissue (made with control crab extract). A set of 6 matrix controls (unfortified crab meat) was also analyzed, in which no chloramphenicol was detected. For identification purposes, the ion ratios (of each daughter ion versus the base daughter ion) of the fortified crab versus those of the chloramphenicol standards agreed within 10% (relative) at fortified chloramphenicol concentrations of 0.25-1.0 ppb.     

Determination of the metabolites of gestrinone in human urine by high performance liquid chromatography, liquid chromatography/mass spectrometry and gas chromatography/mass spectrometry

Gestrinone was studied by high performance liquid chromatography (HPLC) for screening and by gas chromatography/mass spectrometry (GC/MS) for confirmation. When the chromatograms of blank, spiked urine and dosed urine were compared by HPLC, two unknown metabolites were found and these were excreted as the conjugated forms. Metabolites 1 and 2 were tested by LC/MS and LC/MS/MS and both had parent ions at m/z 325. The fragment ion of metabolite 1 was at m/z 263 and ions for metabolite 2 were m/z 307 [MH - H(2)O](+), 289, 279 and 241. LC/MS/MS of m/z 263 as the parent ion of metabolite 1 gave fragment ions at m/z 245 and 217, which were assumed to be [263 - H(2)O](+) and [235 - H(2)O](+), respectively. The trimethylsilyl (TMS)-enol-TMS ether derivative of gestrinone displayed three peaks in its GC/MS chromatogram, formed by tautomerism.     

高效液相色谱-电喷雾离子阱质谱联用测定尿中的8-羟基脱氧鸟嘌呤

建立了尿样中8-羟基脱氧鸟嘌呤的HPLC-MS测定方法.尿样中的8-羟基脱氧鸟嘌呤采用WCX固相萃取小柱预富集后,以0.5%甲酸-甲醇洗脱,吹干后用0.5 mL流动相溶解剩余物上机测定.采用分子的二级碎片,方法在5.0～500.0 μg/L范围内呈良好线性关系,相关系数r=0.999 4,检出限(S/N=3)为0.50...     

高效液相色谱串联质谱法测定牛奶中的高氯酸盐

建立了高效液相色谱-串联质谱测定牛奶中高氯酸盐的方法.样品经1%乙酸-乙腈(体积比1:4)混合溶液提取,于6 000 r/min离心20 min后,经0.2μ m的尼龙滤膜、On-GuardⅡRP柱、On-GuardⅡAg柱和On-GuardⅡBa柱净化,最大反相性能色谱柱C12(Synergi 4u MAX-RP 8...