高效液相色谱-二极管阵列检测法测定L-丙氨酸与L-氨基丙醇

建立了柱前衍生同时测定L丙-氨酸、L氨-基丙醇的高效液相色谱方法。色谱条件为:Shim-pack VP-ODS柱(150 mm×4.6 mm.ID.,5μm);二极管阵列检测器;流动相为甲醇-磷酸盐缓冲溶液(NaH2PO4浓度为0.02 mol/L,pH 4.00 H3PO4调节)(体积比为30∶70),流速为0.5 mL/m in,检测波长为222 nm,柱温为30℃。L丙-氨酸与L氨-基丙醇的线性范围分别为2.30~178 mg/L和9.3~8690 mg/L;检出限分别为1.1 mg/L和1.6 mg/L;日内、日间测定的相对标准偏差(RSD)分别为0.22%、0.46%和0.02%、0.03%。     

食用菌中多菌灵残留的分散固相萃取/高效液相色谱法测定

建立了食用菌中多菌灵残留量的测定方法.采用乙腈提取样品,提取液经十八烷基硅烷(ODS)和乙二胺-N-丙基硅烷(PSA)吸附净化后,采用反相高效液相色谱-紫外可见检测器进行测定,外标法定量.色谱条件:色谱柱为Agilent Eclipse XDB C18柱(4.6 mm×150 mm,5 μm,i.d.),流动相为甲醇-0.02 mol/L磷酸盐缓冲溶液(pH 7.4)(体积比25 ∶ 75),流速1 mL/min,柱温30 ℃,检测波长282 nm.结果表明,多菌灵在0.05 ～10 mg/L质量浓度范围内线性良好,相关系数为0.999 9;方法的相对标准偏差(RSD)不大于3.4%,添加回收率为81% ～98%;多菌灵在食用菌中的检出限(LOD)和定量下限(LOQ)分别为0.03、0.10 mg/kg.该方法操作简单快速、准确度高,能够满足多菌灵残留限量标准的检测要求.     

离子色谱-抑制电导检测法同时测定草甘膦母液中的含磷副产物及无机阴离子

建立了一种抑制电导检测-离子色谱(IC)同时测定草甘膦生产工艺中母液里的草甘膦及其副产物、无机阴离子的方法。样品经过滤后直接进样,色谱条件: IonPac AS11-HC分离柱(250 mm×4 mm)和IonPac AG11-HC保护柱(50 mm×4 mm),在线淋洗液发生器KOH梯度淋洗,流速1.0 mL/min,采用抑制电导检测。草甘膦、甲基草甘膦、六甲基磷酰三胺(HMPA)、增甘膦、亚磷酸、磷酸、Cl~和SO2~4的线性范围分别为0.1～20 mg/L、0.1～20 mg/L、0.1～50 mg/L、0.25～50 mg/L、0.05～20 mg/L、0.2～50 mg/L、0.02～20 mg/L和0.05～50 mg/L,相关系数分别为0.9995、0.9993、0.9999、0.9998、0.9999、0.9985、0.9999和0.9980,加标回收率为93.7%～104.0%,相对标准偏差均小于2.5% (n=7),检出限(以信噪比(S/N)=3计)为0.002～0.025 mg/L。该方法用于草甘膦生产工艺中母液里草甘膦及其含磷副产物和无机阴离子的测定,结果令人满意。     

高效阴离子交换色谱-脉冲安培检测法测定乳粉中的低聚果糖

建立了测定乳粉中低聚果糖的高效阴离子交换色谱-脉冲安培检测(HPAEC-PAD)方法。样品经50%(v/v)乙醇水溶液提取,On Guard RP柱除脂,CarboPac PA200阴离子交换色谱柱(250 mm×3 mm)分离。采用水、0.2 mol/L NaOH溶液和0.4 mol/L NaAc溶液三元梯度淋洗,流速为0.4 mL/min,柱温为30 ℃,进样量为25 μL,脉冲安培检测器检测。蔗果三糖、四糖、五糖在0.05~10 mg/L范围内线性关系良好,相关系数(r²)> 0.9993;定量限分别为0.02、0.005和0.02 mg/L。在0.5、1.0、5.0 mg/L添加水平下,蔗果三糖、四糖、五糖的平均回收率为86.0%~114.0%。该方法处理简单、结果准确、灵敏度高,适用于乳粉中低聚果糖的测定。     

HPLC法同时测定石蒜中加兰他敏和石蒜碱

建立了高效液相色谱同时测定石蒜中加兰他敏和石蒜碱含量的方法。 采用phenomenex-C18色谱柱,以乙腈(A)-0.1%TFA水溶液(B)为流动相梯度洗脱,检测波长289 nm。 结果表明,加兰他敏和石蒜碱均在0.5～10 mg/L(r=0.9999)呈现良好的线性关系,最低检测限(S/N=3)分别为0.09和0.15 mg/L,平均加样回收率分别为99.53%和96.82%。 该方法简单、快速、准确,适合于石蒜中加兰他敏和石蒜碱的测定。     

离子色谱法测定循环冷却水中的羟基-1,1-亚乙基二磷酸

建立了循环冷却水中羟基-1,1-亚乙基二磷酸(HEDP)的离子色谱检测方法。色谱柱为IonPac AS14A阴离子交换柱,流动相为80 mmol/L NaOH水溶液,流速1.0 mL/min,抑制型电导检测器检测。方法的线性范围为0.25～25 mg/L,平均回收率为102%,检出限为0.1 mg/L;对0.25 mg/L和0.5 mg/L的HEDP标准溶液分别进行13次平行测定,相对标准偏差(RSD)分别为4.7%和3.5%。该方法具有简单、快速、灵敏、抗干扰等优点,用于循环冷却水中HEDP的检测,结果令人满意。     

高效液相色谱法测定水性涂料中的酚类防霉剂

建立了简便、准确的高效液相色谱法检测涂料样品中五氯苯酚(PCP)、四氯苯酚(TeCP)和邻苯基苯酚(OPP)。选用C18柱为分离柱,以甲醇-10 mmol/LNH4Ac为流动相进行梯度洗脱,二极管阵列检测器检测,检测波长为220 nm。在该色谱条件下,PCP、TeCP、OPP分析线性范围分别为0.02~200 mg/L,0.02~200 mg/L,0.04~200 mg/L;最低检测浓度分别为0.01、0.01、0.02 mg/L,分别相当于涂料中的质量分数为5.0×10-4%,5.0×10-4%,1.0×10-3%;方法加标回收率为96.6%~103.6%,相对标准偏差为0.98~4.3%(n=7)。本法能满足涂料中PCP、TeCP、OPP的分析测定。     

高效液相色谱法测定化妆品中α-、β-熊果苷及烟酰胺

建立了美白类化妆品中熊果苷的两种光学异构体α-熊果苷和β-熊果苷及烟酰胺的高效液相色谱检测方法。样品用氯化钠水溶液-氯仿(2:1, v/v)进行萃取。固定相为依利特ODS-BP柱(200 mm×4.6 mm, 5 μm),流动相为甲醇-水(10:90, v/v),柱温为25 ℃,检测波长为220 nm,流速为0.5 mL/min,进样量为20 μL。在上述条件下α-熊果苷、β-熊果苷和烟酰胺的质量浓度依次在0.07~50, 0.06~50, 0.05~50 mg/L时与色谱峰面积之间的线性关系良好,相对标准偏差(n=7)分别为1.65%、1.73%和1.33%。将该方法用于化妆品的检测,回收率为91.7%～109.6%。该法简便、快速、准确,可用于化妆品美白成分的测定。     

超高效液相色谱法同时测定布洛芬注射液中布洛芬和精氨酸的含量

建立了一种同时测定布洛芬注射液中布洛芬和精氨酸含量的超高效液相色谱方法。精氨酸与衍生化试剂2,4-二硝基氟苯(DNFB)反应后,与布洛芬同时在超高效液相色谱-二极管阵列检测器(UPLC-PDA)上检测。采用BEH C18色谱柱(50 mm×2.1 mm, 1.7 μm),以乙腈-0.05 mol/L磷酸二氢钾缓冲液(pH 2.5)为流动相进行梯度洗脱,流速为0.4 mL/min,柱温为30 ℃,检测波长分别为357 nm(精氨酸衍生物)和220 nm(布洛芬)。结果表明,布洛芬与精氨酸分别在2.0～100.5 mg/L和1.7～84.5 mg/L范围内呈良好的线性关系,相关系数(r)均为0.9997;平均回收率分别为99.8%和99.6%,相对标准偏差(RSDs)分别为0.37%和0.25%;定量限(信噪比（S/N）=10)分别为0.1 ng和0.2 ng;检出限(S/N=3)分别为0.03 ng和0.05 ng。本方法快速、准确,重复性好,可较全面地评价布洛芬注射液的质量。     

离子液体中卤素离子杂质的离子色谱-直接电导检测法分析

研究了离子色谱-直接电导检测法分离测定离子液体中的卤素离子(F~-、Cl~-、Br~-)杂质.采用Shim-pack IC-A3阴离子交换色谱柱,考察了淋洗液种类及浓度、流速和色谱柱温度对分离测定的影响.最佳色谱条件为:以1.25 mmol/L邻苯二甲酸氢钾为淋洗液,流速1.5 mL/min,色谱柱温45 ℃.在此条件下可以基线分离卤素离子,且NO~-_3、BF~-_4、SO~(2-)_4不干扰测定.该法测定卤素离子的检出限(S/N=3)为0.02 ～0.11 mg/L,峰面积的相对标准偏差(n=5)不大于0.7%,F~-、Cl~- 和Br~- 的标准曲线的线性范围分别为0.1 ～50、0.1 ～50、0.5 ～100 mg/L.将方法用于烷基咪唑四氟硼酸盐离子液体中卤素离子杂质的测定,加标回收率为98% ～102%.     

改进的高效液相色谱法测定婴幼儿配方奶粉中5种核苷酸

建立并优化了高效液相色谱检测婴幼儿配方奶粉中5种核苷酸(尿嘧啶核苷酸(UMP)、腺嘌呤核苷酸(AMP)、次黄嘌呤核苷酸(IMP)、鸟嘌呤核苷酸(GMP)、胞嘧啶核苷酸(CMP))的方法。样品用水提取后,经乙酸沉淀蛋白质和HLB固相萃取柱净化,采用Waters XBrigde Amide(150 mm×4.6 mm,3.5μm)色谱柱分离,以乙腈、10 mmol/L磷酸二氢钠溶液和0.12%(v/v)磷酸溶液为流动相进行梯度洗脱,二极管阵列检测器(波长为254nm)检测。结果表明,5种核苷酸检测的线性范围宽,相关性好,相关系数(r2)均为0.999 9;方法的加标回收率为86.9%~105.7%;定量限为5.6~8.0 mg/kg;日内和日间精密度分别为0.5%~1.7%(n=5)和0.6%~1.9%(n=9)。该法前处理简单,分离效果好,回收率高,重复性好,可作为婴幼儿配方奶粉中5种核苷酸的有效检测方法。     

棉宝中常见单磷酸核苷酸的高效 液相色谱分离与测定

建立了以浓度为 0.05mol/L 的 KH     

HILIC-MS/MS method for the quantitation of nucleotides in infant formula and adult nutritional formula: First Action 2011.21

Official Method 2011.21 is for the quantitation of the following nucleotides: adenosine 5'-monophosphate (AMP), guanosine 5'-monophosphate (GMP), uridine 5'-monophosphate (UMP), cytidine 5'-monophosphate (CMP), and inosine 5'-monophosphate (IMP) in infant formula and adult/pediatric nutritional formula. It uses hydrophilic interaction liquid chromatography with tandem mass spectrometry (HILIC-MS/MS). Preparation of the internal standards was conducted using centrifugal ultrafiltration and the standards are AMP- (13)C10, (15)N5; GMP-(13)C10, (15)N5; UMP-(13)C9, (15)N2; and15 CMP- (13)C9, (15)N3. Data were collected by using multiple reaction monitoring of the product ions of protonated molecules of the five nucleotides generated by positive-electrospray ionization. The HILIC conditions were conducted with ammonium formate (30 mmol/L) in water (pH 2.5, adjusted with formic acid) and methanol. The LOD and LOQ of the standard solution were 0.005-0.01 and 0.01-0.03 microg/mL, respectively. Recovery data were collected for intraday and interday testing and ranged from 98.1 to 108.9% with an RSD of 0.7-5.4%. The analytical range of the method is between 0.04 to 5 microg/mL for standard solution.     

Semiempirical studies on the interactions of dialkyldi(aquo)tin cations, [R2Sn(H2O)2]2+, with selected nucleotides

Semiempirical calculations have been carried out on the interactions of [R₂Sn(H₂O)₂]²⁺, [R = H(CH₂)_n: n = 1–8], mainly with five nucleotides, 5′‐adenosine monophosphate (5′‐AMP), but also with guanosine 5′‐monophosphate (5′‐GMP), cytidine 5′‐monophosphate (5′‐CMP), uridine‐5′‐monophosphate (5′‐UMP) and inosine 5′‐monophosphate (5′‐IMP). The preferred sites of interaction were calculated to be the ribose O2 and O3 hydroxyl oxygens and/or the phosphate oxygens, with the nitrogen sites in the bases the least attractive to the tin compounds. This is in general agreement with experimental findings. Structures of the 1:1 coordination complexes vary from distorted tetrahedral, to distorted trigonal pyramidal to distorted octahedral geometries. Copyright © 2007 John Wiley & Sons, Ltd.     

Cytosine to uracil conversion through hydrolytic deamination of cytidine monophosphate hydroxy‐alkylated on the amino group: a liquid chromatography – electrospray ionization – mass spectrometry investigation

A novel pathway for cytosine to uracil conversion performed in a micellar environment, leading to the generation of uridine monophosphate (UMP), was evidenced during the alkylation reaction of cytidine monophosphate (CMP) by dodecyl epoxide. Liquid chromatography‐electrospray ionization – ion trap ‐ mass spectrometry was used to separate and identify the reaction products and to follow their formation over time. The detection of hydroxy‐amino‐dodecane, concurrently with free UMP, in the reaction mixture suggested that, among the various alkyl‐derivatives formed, CMP alkylated on the amino group of cytosine could undergo tautomerization to an imine and hydrolytic deamination, generating UMP. Interestingly, no evidence for this peculiar conversion pathway was obtained when guanosine monophosphate (GMP), the complementary ribonucleotide of CMP, was also present in the reaction mixture, due to the fact that NH₂‐alkylated CMP was not formed in this case. The last finding emphasized the role played by CMP–GMP molecular interactions, mediated by a micellar environment, in hindering the alkylation reaction at the level of the cytosine amino group. Copyright © 2012 John Wiley & Sons, Ltd.     

Determination of monophosphate nucleotides by capillary electrophoresis inductively coupled plasma mass spectrometry

A preliminary study of a modified microconcentric nebulizer (CEI-100, CETAC) as the sample introduction device of capillary electrophoresis inductively coupled plasma mass spectrometry (CE-ICP-MS) for the determination of monophosphate nucleotides is described. The monophosphate nucleotides studied include adenosine 5'-monophosphate (AMP), guanosine 5'-monophosphate (GMP), uridine 5'-monophosphate (UMP) and inosine 5'-monophosphate (IMP). The species studied were well separated using a 70 cm length x 75 microm id fused silica capillary while the applied voltage was set at -22 kV and a 20 mmol l(-1) ammonium citrate/citric acid buffer (pH 4.0) containing 0.1% m/v cationic polymer (hexadimethrine bromide, Polybrene) was used as the electrophoretic buffer. The electroosmotic flow was reversed by flushing the fused silica capillary with 0.2% m/v Polybrene to accelerate separation. The detection limit of various species studied was in the range of 0.036-0.054 microg P ml(-1), which corresponded to the absolute detection limit of 1.1-1.6 pg P based on the injection volume of 30 nl. We determined the concentrations of nucleotides in two IG-enriched monosodium glutamates purchased from the local market. The recovery was in the range of 100-112% for various species, and the concentrations of IMP and GMP in these samples were in the range of 0.15-0.18% m/m.     

Borate-nucleotide complex formation depends on charge and phosphorylation state

Flow injection analysis with electrospray ionization mass spectrometry was used to investigate borate-nucleotide complex formation. Solutions containing 100 microM nucleotide and 500 microM boric acid in water-acetonitrile-triethylamine (50:50:0.2, v/v/v; pH 10.3) showed that borate complexation with nicotinamide nucleotides was significantly influenced by the charge on the nicotinamide group and the number of phosphate groups on the adenine ribose. Borate binding decreased in the order of NAD(+), NADH, NADP(+) and NADPH. To investigate the relationship between complex formation and phosphorylation, association constants (K(A)) of borate-adenine (AMP, ADP, ATP), -guanine (GMP, GDP, GTP), -cytidine (CMP, CDP, CTP) and -uridine (UMP, UDP, UTP) complexes were compared. The results showed that the number of nucleotide phosphate groups was inversely proportional to the relative abundance of the borate complexes, with the K(A) of borate-nucleotide complex decreasing in the order mono-, di- and tri-phosphates (AMP approximately GMP approximately CMP approximately UMP > ADP approximately GDP approximately CDP approximately UDP > GTP > ATP approximately CTP approximately UTP). At pH 7.4, using ammonium bicarbonate buffer, only borate-NAD(+) complex was observed. This indicates that the borate-NAD(+) complex may be the most physiologically relevant of those studied.     

离子色谱法测定增味剂中的5′-肌苷酸二钠和5′-鸟苷酸二钠

建立了增味剂中5′-肌苷酸二钠和5′-鸟苷酸二钠的离子色谱分析方法。采用lonPacASll阴离子交换色谱柱,以20mmol／LNa2CO3一体积分数为15％的甲醇溶液为淋洗液,检测波长254um。方法已用于实际样品的测定。     

离子色谱法测定增味剂中的5′-肌苷酸二钠和5′-鸟苷酸二钠

 建立了增味剂中5′-肌苷酸二钠和5′-鸟苷酸二钠的离子色谱分析方法。采用lonPacASll阴离子交换色谱柱,以20mmol／LNa2CO3一体积分数为15％的甲醇溶液为淋洗液,检测波长254um。方法已用于实际样品的测定。     

超高效液相色谱法测定婴幼儿配方奶粉中的叶黄素

建立了采用超高效液相色谱测定婴幼儿配方奶粉中叶黄素的检测方法。样品经丙酮溶液提取,离心分层,冷冻离心去脂,YMC Carotenoid C30色谱柱（150 mm×4.6 mm,3 μm）分离。以甲醇-甲基叔丁基醚（70：30,v/v）为流动相等度洗脱,流速为0.5 mL/min,进样量5 μL,柱温25 ℃,二极管阵列检测器检测,检测波长445 nm。方法在20~500 μg/L范围内线性关系良好;相关系数为0.999 9;定量限为20 μg/L。添加量在50、250、2000 μg/kg时,叶黄素的回收率为97.9%~104.4%。本方法操作简便,结果准确,灵敏度高,适用于婴幼儿奶粉中叶黄素的测定。