Gas chromatographic-mass spectrometric study of deacetylation and oxidation of 2-acetylaminofluorene by rat liver epithelial cell lines upon cocarcinogen induction

Cell line cultures from postnatal and adult rats were incubated with 5-100 mumol/l [9-14C]-2-acetylaminofluorene. On incubation of 10 mumol/l, ring-hydroxylated metabolites, expressed as nmol hydroxy-2-acetylaminofluorene (OH-2-AAF)/mg cell protein/24 h, were 9-OH- 1.28 +/- 0.37, 7-OH- 1.08 +/- 0.28 and 5-OH- 0.30 +/- 0.08, and deacetylated 2-AAF (2-AF) 1.20 +/- 0.18. For 5, 10, 50 and 100 mumol/l 2-AAF, the total production of OH-2-AAF (same units) and 2-AF (%) were, respectively, 0.86 (0%), 3.86 (35%), 17.8 (60%) and 35.03 (89%). On preincubation with phenobarbital (BP) or 3-methylcholanthrene (3-MC) and then incubation of 10 mumol/l 2-AAF, the total synthesis of OH-2-AAF increased 1.9-fold (PB) and 2.5-fold (3-MC). In addition, four other OH-2-AAF (1-OH-, 3-OH- and two unknown OH-2-AAF) were produced and glucuronidation of all metabolites was induced and amounted to 57% of the total after PB and 75% after 3-MC preincubation. Metyrapone or alpha-naphthoflavone inhibition of BP or 3-MC, respectively, markedly affected the production of free and conjugated metabolites and, almost completely, the deacetylation of 2-AAF.     

Determination of 5-fluorouracil and 5-fluoro-2'-deoxyuridine-5'-monophosphate in pancreatic cancer cell line and other biological materials using capillary electrophoresis

Capillary zone electrophoresis (CZE) was used for the rapid determination of 5-fluorouracil (5-FU) and 5-fluoro-2'-deoxyuridine-5'-monophosphate (FdUMP) in pancreatic cancer cell line (PANC-1), culture medium, plasma and pancreatic tissue. The assay is based upon protein precipitation with acetonitrile followed by a 9-min CZE analysis of the supernatant in an uncoated fused-silica capillary employing a borate buffer and on-column absorbance detection at 265 nm. Using 50 microl of sample, 5-FU levels between 4.12 and 132 microg/ml (31.7-1000 microM) were found to provide linear calibration graphs. Intra-day and inter-day RSD values evaluated from peak height ratios (n=5) were <7.6 and <8.8%, respectively. Corresponding RSD values of detection times (n=7) were <1 and <1.5%, respectively. The limits of detection for 5-FU and FdUMP were 1.72 and 5.29 microg/ml, respectively. As application, the accumulation of 5-FU by PANC-1 cells over a 4-h time period was investigated. Having a culture medium concentration of 100 microg/ml, the 5-FU cell content was estimated to become equal to that of the surrounding medium (i.e., 100 microg/ml or 3.61 fmol per cell with a volume of 4.7 pl) within that time period. The sensitivity of the assay was sufficient for the determination of 5-FU in all cell samples. FdUMP, however, could not be detected in these samples. Furthermore, the data obtained in uncoated capillaries are compared to those measured in a fused-silica capillary whose inner surface was coated with linear polyacrylamide (about 10-fold reduction of electroosmosis). The latter capillary format was found to be useless for simultaneous analysis of 5-FU and FdUMP in pancreatic cells but could be potentially useful for analysis of these compounds in plasma.     

Determination of purine and pyrimidine bases in DNA by micellar electrokinetic capillary chromatography with electrochemical detection

A method based on micellar electrokinetic capillary chromatography with electrochemical detection was developed for the determination of cytosine, 5-methylcytosine (5-MC), thymine, adenine, and guanine in the hydrolysates of DNA. The working electrode was fabricated in a novel self-positioning carbon disc electrode system that can align the capillary outlet with the working electrode without a three-dimensional micromanipulator. The five analytes could be well separated within 10 min in a 40 cm length capillary at a separation voltage of 9 kV in a 40 mmol/l borate buffer (pH 10.0) containing 100 mmol/l sodium dodecyl sulfate. Good linearity was observed between peak current and concentration of bases over three orders of magnitude with the detection limits (SIN=3) ranging from 1.28 x 10(-6) to 5.02 x 10(-6) mol/l. This proposed method demonstrated long-term stability and reproducibility with relative standard deviations of less than 5% for both migration time and peak current (n=7). It has been successfully applied to determine bases including 5-MC in the hydrolysates of fish sperm DNA, calf thymus DNA, and DNA isolated from spleen cells of female mice.     

High-performance liquid chromatographic method with ultraviolet detection for the determination of dapsone and its hydroxylated metabolite in human plasma

A validated high-performance liquid chromatographic method with ultraviolet detection for the quantitative determination of dapsone (4,4'-diaminodifenyl sulfone, DDS) and a metabolite, hydroxylaminodapsone (4-amino-4-hydroxylaminodiphenyl sulfone, DDS-NOH), in human plasma is described. Human plasma was deproteinized with acetone and the clear supernatant solution after centrifugation was evaporated to dryness under a gentle stream of nitrogen at 70 degrees C. The residue was dissolved in a mixture of HPLC eluent and acetone (18:5 v/v) and an aliquot of this solution (50 microL) was injected onto the HPLC column. Dapsone, hydroxylaminodapsone and diazoxide as internal standard, were separated within 10 min by isocratic elution with water:acetonitrile:glacial acetic acid:triethylamine (80:20:1.0:0.5 by volume) as eluent. Detection was by ultraviolet at the wavelength of 295 nm. The within-day repeatability coefficients of variation were 3-5% for dapsone (0.301-20.0 mg/L, n = 5) and 3-5% for hydroxylaminodapsone (0.0948-6.32 mg/L, n = 5), whereas the between-day repeatability coefficients of variation were 3-8% (0.301-20.0 mg/L, n = 5) for dapsone and 4-10% for hydroxylaminodapsone (0.0948-6.32 mg/L, n = 5). The mean recoveries -were 92-107% (0.301-20.0 mg/L, n = 2), 80-82% (0.0948-6.32 mg/L, n = 2) and 88% (0.0200 mg/mL, n = 5), for dapsone, hydroxylaminodapsone and diazoxide, respectively. The average correlation coefficient of the calibration curve was 0.99988 (n = 5) for dapsone at a concentration range of 0.301-20.0 mg/L, whereas the average correlation coefficient of the hydroxylaminodapsone calibration curve was 0.99981 (n = 5) at a concentration range of 0.0948-6.32 mg/L. The limits of detection were 0.00200 and 0.0470 mg/L for dapsone and hydroxylaminodapsone, respectively. The method is suitable for drug level monitoring and for pharmacokinetic studies.     

Determination of metrifonate and dichlorvos in whole blood using gas chromatography and gas chromatography-mass spectrometry

Analytical methods for determining metrifonate and dichlorvos in whole blood and a sampling procedure suitable for pharmacokinetic studies in man are described. Metrifonate concentrations were determined after chloroform extraction using gas chromatography-nitrogen-phosphorus detection. The within-assay coefficients of variation were 4 and 9% at 19.4 and 0.8 mumol/l (limits of determination), respectively. Dichlorvos was determined using gas chromatography-mass spectrometry of toluene extracts. The within-assay coefficients of variation were 2 and 5% at 225 and 50 nmol/l (limits of determination), respectively. Since both substances are chemically unstable, the blood was collected by dripping it directly from the vein into 0.74 M phosphoric acid.     

Cathodic stripping voltammetry of the anticancer agent 5-fluorouracil and determination in urine

Cathodic stripping voltammetry was used to determine 5-fluorouracil (5-FU) in the presence of traces of Cu(II). It was found that the addition of 5 x 10(-9) mol dm(-3) Cu(II) to the measurement cell greatly enhanced the peak current of the adsorbed molecule. Different parameters were tested to optimize the conditions for the determination of 5-FU. The adsorbed form is reduced irreversibly. It was observed that by controlling the deposition potential, the technique could be directed to the determination of Cu(II) or the drug. The linear range was from 5 x 10(-9) to 6 x 10(-8) mol dm(-3) for 5-FU and from 6 x 10(-9) to 5 x 10(-8) mol dm(-3) for Cu(II). Detection limits of 4.6 x 10(-10) and 5 x 10(-10) mol dm(-3) were obtained for 5-FU and Cu(II), respectively. The method was applied to urine and molecules or ions which may interfere were studied.     

裂解氢化气相色谱/质谱法对聚乙烯类塑料裂解氢化产物微细结构的鉴别

采用裂解氢化气相色谱/质谱(Py-H-GC/MS)分析技术,对国内12个厂家、国外12个厂家生产的高密度聚乙烯、低密度聚乙烯、线性低密度聚乙烯及乙烯和α-烯烃共聚物类塑料的47个样品进行了分析。发现主链中存在的甲基短支链特征组分的含量与聚乙烯的类别有关,根据裂解氢化产物C12～C13之间存在的4个甲基短支链（5-甲基十二烷(5-MC12)、4-甲基十二烷(4-MC12)、2-甲基十二烷(2-MC12)、3-甲基十二烷(3-MC12)）相对含量的变化,可以将47个样品划分为8个类别。该方法的建立为法庭科学中常见的聚乙烯类塑料物证的鉴别提供了进一步的科学分析依据。     

胶束扫集毛细管电动色谱法测定药物中3种邻苯二甲酸酯

采用胶束扫集毛细管电动色谱技术,建立了测定药物中邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DZP)和邻苯二甲酸二丁酯(DBP)的方法。电泳缓冲体系含80 mmol/L SDS,20 mmol/L NaH2PO4(pH 2.20),5%甲醇(V/V),分离电压-18 kV,重力进样80s×15.0cm,检测波长225 nm,使用Φ50μm×62.0 cm石英毛细管,有效长度50.0 cm。讨论了磷酸盐浓度、有机改善剂、SDS浓度、分离电压、进样时间等因素的影响,并考察了胶束扫集法对DMP、DEP和DBP的富集能力。在优化条件下,线性关系良好,相关系数大于0.9986,DMP、DEP和DBP的线性范围分别为1.25～240,1.04～200和1.56～200 mg/L,检出限分别为0.26,0.26和0.39 mg/L。方法应用于肠溶片中DMP、DEP和DBP的测定,回收率在93.3%～108%之间,RSD≤5.2%。每次样品测定可在10 min内完成。     

Simultaneous determination of Cr(III)-EDTA and Cr(VI) by ion interaction chromatography using a C18 column

The simultaneous determination of Cr(III) and Cr(VI) by ion interaction chromatography has been investigated. The mobile phase consisted of a 5 mM octylammonium orthophosphate at pH 4.0 with 35% (v/v) MeOH. The Nucleosil-100, C18 (5 microm, 250 x 4.6 mm) was used as the separating column and the component was detected at 200 nm. The separation of Cr(III) and Cr(VI) was based on anionic interaction. Since the Cr(III) did not exist as an anionic form like the Cr(VI) (Cr2O7(2-)) presented at the optimum condition, Cr(II) was firstly reacted with EDTA (1:40 mole ratio) to form the anionic complex prior to injecting into the chromatographic system. The characteristics of the method for separation of Cr(III)-EDTA and Cr(VI) were satisfactory. The wide linear range (0.3-50.0 mg l(-1)) was achieved. The repeatabilities (%R.S.D.) calculated from peak areas were 0.49% and 0.14%, detection limit (signal to noise ratio of 3) of 0.02 mg l(-1) and 0.3 mg l(-1) were obtained and the average of percent recoveries were found to be 98.5% and 99.6% for Cr(III) and Cr(VI), respectively.     

Application of ion-exchange cartridge clean-up in food analysis. II. Determination of benzylpenicillin, phenoxymethylpenicillin, oxacillin, cloxacillin, nafcillin and dicloxacillin in meat using liquid chromatography with ultraviolet detection.

A multiresidue analytical method was developed for the simultaneous determination of benzylpenicillin (PCG), phenoxymethylpenicillin (PCV), oxacillin (MPIPC), cloxacillin (MCIPC), nafcillin (NFPC) and dicloxacillin (MDIPC) in meat. The method involves the use of an ion-exchange cartridge for sample clean-up followed by ion-pair high-performance liquid chromatography with ultraviolet detection. The recoveries of PCG, PCV, MPIPC, MCIPC, NFPC and MDIPC from pork muscle spiked at levels of 0.5, 0.1 and 0.05 mg/kg were in the range of 77-90, 73-95 and 80-93% with coefficients of variation of 0.5-1.7, 1.6-4.4 and 3.2-6.6%, respectively. For beef muscle spiked at levels of 0.5, 0.1 and 0.05 mg/kg, the recoveries of these compounds were 83-92, 71-86 and 77-90% with coefficients of variation of 1.7-4.4, 2.6-7.0 and 3.9-6.4%, respectively. The detection limits for each penicillin were 0.02 mg/kg in meat.     

柱前衍生高效液相色谱法测定二乙醇胺脱氢产物亚氨基二乙酸和甘氨酸

以对甲苯磺酰氯(PTSC)为衍生剂,建立了柱前衍生高效液相色谱(HPLC)测定二乙醇胺脱氢产物中亚氨基二乙酸(IDA)和甘氨酸(Gly)含量的分析方法。IDA和Gly与衍生剂在碱性(pH 11)条件下于45℃反应15 min,进行柱前衍生,并利用高效液相色谱-质谱对衍生产物进行定性分析。衍生化产物采用VP-ODS色谱柱(200 mm×4.6 mm,5μm)分离,以0.03 mol/L醋酸铵溶液(pH 5.5)为流动相A、乙腈为流动相B(体积比为87∶13),进行等度洗脱,流速为1 mL/min,并采用配有紫外检测器的高效液相色谱仪测定,检测波长为235 nm。该法在IDA质量浓度为900~2 100 mg/L、Gly质量浓度为20~100 mg/L的范围内线性关系良好,相关系数(R2)均大于0.999。IDA和Gly的检出限(LOD)分别为0.089 7 mg/L和0.026 2 mg/L,加标回收率分别为98.7%~99.3%和98.0%~99.5%,相对标准偏差(RSD)分别为0.89%~1.23%和0.95%~1.11%(n=3)。该法具有反应条件温和、准确性高的特点,可用于工艺生产中IDA和Gly含量的测定。     

以离子液体作流动相添加剂的高效液相色谱法测定复方苦参注射液中4种生物碱

将离子液体1-丁基-3-甲基咪唑四氟硼酸盐(［BMIM］BF4)作为流动相添加剂建立了同时测定复方苦参注射液中4种主要生物碱的HPLC分析方法。以Agilent TC-C18柱(250 mm×4.6 mm, 5 μm)为分离柱,甲醇-0.1%磷酸水溶液(含2.2×10-4mol/L ［BMIM］BF4)(5:95, v/v)为流动相,流速1.0 mL/min,柱温30 ℃,进样量20 μL,在205 nm下检测。结果表明,苦参碱、槐定碱、氧化槐果碱以及氧化苦参碱的质量浓度分别在25.8～155.0 mg/L, 40.0～240.0 mg/L, 21.7～130.0 mg/L和37.5～225.0 mg/L范围内线性关系良好,相关系数均大于0.9990,平均回收率(n=9)在96.2%和98.9%之间。离子液体的加入能明显改善C18柱分离生物碱的色谱峰形并提高分离度。本法简便、快速、重复性好,可用于复方苦参注射液中生物碱的分离与测定。     

高效液相色谱法同时测定香兰素与邻位香兰素

建立了同时测定香兰素和邻位香兰素的高效液相色谱法.考察了流动相组成、柱温等因素对分析效率的影响.在流动相为5% 乙酸-乙腈(60 :40,体积比),流速1.0 mL/min,柱温25 ℃的优化条件下,香兰素和邻位香兰素可在5 min内实现分离.测定结果表明,香兰素和邻位香兰素在10 ～240 mg/L范围内线性关系良好...     

Application of the slotted quartz tube in flow-injection flame atomic-absorption spectrometry

The slotted quartz has been applied to flow-injection flame atomic-absorption spectrometry (FI-FAAS) showing several important advantages. The tube life was improved by a factor of 5-6 compared to conventional continuous aspiration. Flow impact systems were found not to be necessary in the applications so that larger enhancement factors may be achieved without sacrifice in precision. For 1.0 mg/l. copper, 1.0 mg/l. lead, 0.1 mg/l. cadmium and 1.0 mg/l. gold sensitivity enhancement factors of 3.1, 5.5, 5.3 and 4.0 were obtained with precisions of 1.3%, 1.1%, 1.6% and 1.7% RSD (n = 11) respectively. Application of the slotted quartz tube FI-FAAS method to the determination of heavy metals in urine has shown improved tolerance to interfering matrices. Recoveries obtained by spiking undiluted urine samples with 0.1 mg/l. copper and lead, and 0.01 mg/l. cadmium were in the range 100-102%.     

三酰甘油氧化聚合物的制备型快速柱层析-体积排阻色谱测定法

建立了一种简便、灵敏、无需内标的检测油脂中三酰甘油氧化聚合物(TGP)的分析方法。以制备型快速层析柱(PFC)(flash硅胶柱,20 g,40～60μm,6 nm)分离1 g油脂样品中极性组分(PC),经高效体积排阻色谱(HPSEC)(GPC柱,Ф7.8 mm×300 mm,粒径5μm,孔径10 nm)将PC细分为氧化三酰甘油寡聚物(TGO)、氧化三酰甘油二聚物(TGD)、氧化三酰甘油单体(ox-TGM)、二酰甘油(DG)、游离脂肪酸(FFA)。结合重量法测定油脂中PC、面积归一法测定PC中TGP,可准确定量油脂中的TGP含量。结果表明,TGO、TGD分别在28～1 800、11～2 800 mg/L范围内线性关系良好,相关系数(r2)分别为0.998 2、0.998 7,TGO及TGD的检出限(LOD)分别为28、11 mg/L,定量下限(LOQ)分别为113、44 mg/L;相当于油脂中TGP的LOD为0.01%。PFC-HPSEC法检测油脂TGP的相对标准偏差(RSD)均小于10%。PFC对3个PC加标水平(2.27%、8.47%、30.94%)的平均回收率为95%～98%,相对标准偏差(RSD)均低于4%。PFC-HPSEC方法与经典的硅胶柱-HPSEC方法定量油脂TGP的结果吻合度高,相对误差为0～8.9%。该方法能够在2 h内实现各种油脂中TGP含量的定量检测,包括使用过的废弃油脂与未使用的食用油脂,尤其适用于低含量TGP的初榨油和精炼油脂。     

Rapid and simultaneous determination of capecitabine and its metabolites in mouse plasma, mouse serum, and in rabbit bile by high-performance liquid chromatography

A rapid high-performance liquid chromatography method has been developed for simultaneous determination of capecitabine and its metabolites: 5'-deoxy-5-fluorocytidine (5'-DFCR), 5'-deoxy-5-fluorouridine (5'-DFUR) and 5-fluorouracil (5-FU). 5'-DFCR was synthesized by hydrolyzing capecitabine using commercially available carboxyl esterase (CES) and characterized by NMR, mass spectrometry and elemental analysis. Base-line separations between capecitabine, 5'-DFCR, 5'-DFUR and 5-FU were found with symmetrical peak shapes on a Discovery RP-amide C16 column using 10 mM ammonium acetate at pH 4.0 and methanol as the mobile phase. The retention times of capecitabine, 5'-DFCR, 5'-DFUR and 5-FU were 8.9, 5.0, 5.3 and 3.0 min, respectively. Linear calibration curves were obtained for each compound across a range from 1 to 500 microg ml(-1). The intra- and inter-day relative standard deviations (%RSD) were <5%. A single-step protein precipitation method was employed for separation of the analytes from bio-matrices. Greater than 85% recoveries were obtained for capecitabine, 5'-DFCR, 5'-DFUR and 5-FU from bio-fluids including mouse plasma, mouse serum and rabbit bile.     

Quantitative analysis of 2-furfural and 5-methylfurfural in different Italian vinegars by headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry using isotope dilution

A new method was developed for the determination of 2-furfural (2-F) and 5-methylfurfural (5-MF), two products of Maillard reaction in vinegar, with head-space solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). A divinylbenzene (DVB)/carboxen (CAR)/polydimethylsiloxane (PDMS) fibre was used and SPME conditions were optimised, studying ionic strength effect, temperature effect and adsorption time. Both analytes were determined by calibration established on 2-furfural-d4 (2-F-d4). The method showed good linearity in the range studied (from 16 to 0.12 mg/l), with a regression coefficient r2 of 0.9999. Inter-batch precision and accuracy were found between 14.9 and 6.0% and between -11.7 and 0.2%, respectively. Detection limit was 15 microg/l. The method is simple and accurate and it has been applied to a series of balsamic and non-balsamic vinegars.     

Determination of thiazolidine-4-carboxylates in urine by chloroformate derivatization and gas chromatography-electron impact mass spectrometry

The derivatization method of thiazolidine-4-carboxylic acid (TZCA) and methyl-thiazolidine-4-carboxylic acid (Me-TZCA) in urine with alcohol/chloroformate was achieved. TZCA and Me-TZCA were derivatized in one step in urine with ethyl chloroformate in 1 min at room temperature. The derivatives of TZCA and Me-TZCA had very good chromatographic properties and offered very sensitive response for gas chromatography-electron impact ionization-mass spectrometry (GC-EI-MS). On the basis of derivatization, the method for simultaneous determination of TZCA and Me-TZCA in human urine was developed. Deuterated Me-TZCA (Me-TZCA-d(4)) was synthesized as the internal standard (IS) for the analysis of urine samples. TZCA and Me-TZCA were derivatized and extracted from urine at pH 9.5 with toluene, and then the dried extract was dissolved with 100 microl ethyl acetate and injected in GC/MS system. The recoveries of TZCA and Me-TZCA were about 102 and 103%, respectively, at the concentration of 0.05 mg/l. The method detection limits (MDL) were 1.0 and 0.5 microg/l, respectively, for TZCA and Me-TZCA in 1 ml human urine. The coefficients of variation of TZCA and Me-TZCA were less than 6% at the concentrations of 0.05 and 0.2 mg/l, respectively. To assess the formation of TZCA during inhalation with formaldehyde (FA) (about 3.1 and 38.1 ppm FA in air), urine samples from rats were taken during 3 days after initiation of treatment. The mean amount of TZCA determined was 0.07 mg/l in control group and 0.18 mg/l during treatment with 3.1 ppm. The TZCA levels increased up to about 1.01 mg/l during treatment with 38.1 ppm. It is planned to study whether urinary TZCA can be used as an indicator in the biological monitoring of exposure to FA.     

Quantitative determination of melatonin in human plasma and cerebrospinal fluid with high-performance liquid chromatography and fluorescence detection

A validated new and precise reversed-phase high-performance liquid chromatographic method for the determination of melatonin in human plasma and cerebrospinal fluid, with 5-fluorotryptamine as internal standard, is described. Liquid-liquid extraction with dichloromethane was performed under alkaline conditions. After evaporation of the organic solvent, the extract was dissolved in eluent and chromatographed on a base-deactivated octadecyl column, using an eluent composed of 650 mL potassium dihydrogenphosphate solution (0.07 mol/L water), adjusted to a pH of 3.0 with a 43% phosphoric acid solution, mixed with 350 mL methanol. Fluorescence detection at an excitation wavelength of 224 nm and an emission wavelength of 348 nm was used for quantitation. Melatonin and 5-fluorotryptamine chromatographed with retention times of 5.3 and 9. 3 min, respectively. Mean recoveries of 96% (n = 10) and 95% (n = 5) were found for melatonin in plasma and cerebrospinal fluid respectively. 5-Fluorotryptamine was found to have a mean recovery of 90% (n = 10) and 82% (n = 5) in plasma and cerebrospinal fluid, respectively. The repeatability coefficients of variation for both melatonin and 5-fluorotryptamine in plasma were 4-5% [five different samples (r = 5) on two consecutive days (n = 2)], with reproducibility coefficients of 1.6-7% (n = 2, r = 5) and 0.9-4% (n = 2, r = 5) for melatonin and internal standard, respectively. In cerebrospinal fluid the repeatability coefficient of variation of the extraction procedure was 5% (n = 1, r = 5) for melatonin and 7% (n = 1, r = 5) for 5-fluorotryptamine. The correlation coefficients of the calibration curves were 0.9998 (n = 2) in plasma at a concentration range of 0.108-25.9 ng/mL and 0.9994 (n = 2) at a concentration range of 0.108-25.9 ng/mL in cerebrospinal fluid. The limit of detection was determined at 8 pg/mL which enables to measure melatonin concentrations at physiological concentrations reached during daytime.     

固相萃取-气相色谱-串联质谱法测定乳胶儿童用品中15种N-亚硝胺及其前体物的迁移量

建立了同时测定乳胶儿童用品中15种N-亚硝胺及其前体物迁移量的固相萃取-气相色谱-串联质谱(SPEGC-MS/MS)分析方法。以人工唾液作为迁移模拟物,以Chromabond Easy固相萃取柱(填料的主要成分是极性修饰的聚乙烯-二乙烯基苯共聚物)对迁移液中的N-亚硝胺分析物进行净化,采用HP-5 MS UI色谱柱分离,MS/MS在多反应监测模式下进行定性及定量分析。15种N-亚硝胺在5~2 000μg/L范围内呈良好的线性关系,相关系数均大于0.998;方法定量限(S/N=10)为0.625~12.50μg/kg,低于欧盟2 009/48/EC指令的限量要求。在低、中、高3个添加水平的回收率为53.8%~116.2%、52.7%~105.1%和49.5%~102.9%;日内精密度分别为1.3%~14.0%(n=6),日间精密度为1.6%~7.6%(n=4)。采用本方法对婴儿奶嘴样品和气球样品进行了测定,其中4件奶嘴和7件气球样品中检出亚硝胺及其前体物,奶嘴和气球中N-亚硝胺的总检出含量分别为0.049 9~0.126mg/kg和0.515~41.2 mg/kg;N-亚硝胺前体物总检出量分别为0.026 4~0.030 0 mg/kg和0.187~12.5mg/kg。