微波消解-火焰原子吸收法测定垃圾焚烧飞灰中的金属含量

采用NHO3＋HF＋H2O2体系微波消解垃圾焚烧飞灰,火焰原子吸收光谱法测定金属Cu,Fe,Pb,Ni,Mn,Cr和Cd的含量。结果表明,飞灰中Cu质量分数为0．8927mg／g,Pb质量分数为1．8490mg／g,Ni质量分数为0．1523mg／g,Mn质量分数为1．1033mg/g,Fe质量分数为86．4517mg／g,Cr质量分数为0．3667mg／g,Cd质量分数为0．0581mg／g。铁的检测限为3．9041mg／L,其它元素均小于1mg／L,加标回收率在98．0％-108．0％之间。RSD〈4．0％。该法简便快速,具有较好的准确度和精密度,测定结果为处理垃圾焚烧所产生的飞灰提供了理论依据。     

高效液相色谱法测定肉制品中甘草抗氧化物的含量

建立了测定肉制品中甘草抗氧化物含量的方法。样品经流动相提取,采用C．8色谱柱分离,以甲醇-0．2mol／L乙酸铵-冰乙酸（体积比70：29：1）为流动相,流速为1．0mL／min,波长为250nm,以保留时间进行定性,峰面积进行定量。甘草酸在1．0-80．0μg／mL范围内线性关系良好,回归方程为y=8．55×10^-5x-0．599（r=0．9997）,检出限为1．0mg／kg,定量限为3．0mg／kg,加标回收率为95．7％-103．4％,测定结果的相对标准偏差为1．57％-3．53％（n=6）。该方法适用于检验机构日常检验中大批量肉制品中甘草抗氧化物含量的测定。     

ICP—OES测定饰品中砷、镉、汞、铅总量的不确定度评定

在用ICP-OES检测重金属含量过程中,含量在仪器检出限以上的得出正值结果,在仪器检出限以下的往往会产生一些负值观测结果,对饰品中铅、镉、汞、砷总量测定过程产生的正值、负值观测结果（As：-9mg／kg;Cd：46mg／kg;Hg：-4mg／kg;Pb：81mg／kg）进行了不确定度评定,最后结合样品检出限给出报告为As：小于37mg／kg;Hg：小于48mg／kg;Cd：（46±4）mg／kg（k=2）;Pb：（81±8）mg／kg（k=2）。     

HPLC法测定食用香菇中的甲醛

建立了用高效液相色谱测定食用香菇中甲醛的方法。将食用香菇用水提取,提取液经2,4-二硝基苯肼(DNPH)衍生后,用高效液相色谱法测定其中的甲醛。外标法定量测定时,甲醛标准溶液的峰面积与样品质量浓度在10．7～856μg／L范围内呈良好的线性关系,线性回归系数(r2)为0．9998,方法的检出限为8．2μg／L。所测定的6种香菇样品中甲醛的平均加标回收率为72％～93％;相对标准偏差为1％～8％。除了一种野生香菇样品未检出外,其它5种市售香菇样品中甲醛的质量分数为34～292mg／kg。     

30％毒死蜱微乳剂在甘蓝及土壤中的残留动态研究

利用气相色谱（配FPD检测器）分析测定了30％毒死蜱微乳剂在甘蓝和土壤中的残留消解动态和最终残留量。毒死蜱色谱峰面积与质量浓度在0．01～0．5mg／L范围内呈良好的线性关系,相关系数,为0．9992。甘蓝和土壤中毒死蜱的最低检出浓度均为0．005mg／kg,在0．01,0．02,0．1mg／kg3个添加水平下,甘蓝及土壤中毒死蜱的平均回收率分别为80．1％～96．4％和82．1％-98．7％,变异系数分别为1．2％～5．0％和2．5％-3-3％（n=10）。残留消解动态的结果表明：毒死蜱在甘蓝中的半衰期为5．8～10．5d,在土壤中的半衰期为8．0～10．5d。毒死蜱在收获期甘蓝及土壤中最终残留量均低于我国规定的限量值（1．0mg／kg）。     

中草药中有机氯农药和拟除虫菊酯农药残留量的测定

建立了中草药中11种有机氯农药和8种拟除虫菊酯农药的残留气相色谱分析方法。样品用含30％丙酮的乙腈提取,用正己烷进行液液分配,提取液用弗罗里硅土柱净化,采用兰州化物所的农残Ⅱ号毛细管柱分离,用GC-ECD同时检测。在两个水平添加时的回收率(n=5)分别为78．6％～119．7％和86．5％～114．0％,相对标准偏差分别为3．6％～8．7％和4．4％～10．2％。该方法的检出限为：有机氯农药0．005mg／kg,拟除虫菊酯农药0．01mg／kg。方法用于江西中草药样品中农药残留测定,结果满意。     

凝胶渗透色谱-气相色谱质谱法测定：花生中6种除草剂农药残留

建立了凝胶渗透色谱一气相色谱质谱（GPC～GC=MS）法测定花生中6种除草剂（氟乐灵、异恶草酮、甲草胺、二甲戊乐灵、乙氧氟草醚、喹禾灵）农药残留的方法。样品经乙腈提取,氨基固相萃取柱和凝胶渗透色谱净化,在选择离子扫描（SIM）模式下进行气相色谱质谱法测定,外标法定量。6种除草剂浓度在0．02-1．00mg／L范围内与色谱峰面积呈良好的线性,线性相关系数为O．9949～0．9998,添加回收率为77．8％-101．6％,测定结果的相对标准偏差为4．4％～11．4％（月=5）,方法的检出限为0．1～1．3μg／kg。     

异辛烷溶解-直接进样-电感耦合等离子体发射光谱法测定银制品涂层中8种有害元素

建立电感耦合等离子体发射光谱测定银制品表层涂层中硒、砷、锑、铅、镉、汞、铬、钡8种有害元素含量的分析方法。采用异辛烷作为浸泡溶剂，采用装载有机进样附件的电感耦合等离子体发射光谱仪对样品进行测定。8种元素的质量分数在0.0～5.0 mg/kg范围内与光谱强度的线性关系良好，线性相关系数均不小于0.999 8，检出限为0.000 2～0.034 4 mg/kg。加标质量为0.5、2.0、4.0 mg/kg时，测定结果的相对标准偏差分别为0.32%～3.65%、0.41%～2.44%、0.33%～2.82%(n=6)，平均加标回收率分别为100.0%～108.9%、100.8%～108.6%、97.2%～103.8%。     

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）.     

面粉中偶氮甲酰胺含量的高效液相色谱法测定

面粉中偶氮甲酰胺（azodicarbonamide,ADA）用丙酮提取,提取液氮吹浓缩后用20mmol／L乙酸铵的水溶液定容,并用正己烷脱脂。样液供高效液相色谱仪测定,外标法定量。方法的线性范围为0—50mg／L（r=1．000）,定量下限为1．0mg／kg。在面粉基质中分别添加1．0、2．0、50．0mg／kg 3个水平的偶氮甲酰胺标准品,方法的回收率为80％～92％,相对标准偏差小于7％。     

蜂花粉的营养价值研究

蜂花粉经微波消解完全后,通过ICP-OES测定了其多种微量元素的含量.结果表明,蜂花粉中含有丰富的微量元素,平均含量以钙、铁、镁居多,分别为1 118.110、782.135、82.351 mg/kg;其它被检测的微量元素均有一定的含量,且均在人体健康适用范围之内;有毒害性的元素铅、镉含量极微.由此可见,蜂花粉因其含量...     

石墨炉原子吸收光谱法测定压水反应堆硼酸介质中钙

以甘露醇为基体改进剂,建立石墨炉原子吸收光谱法测定压水反应堆硼酸介质中钙含量的方法。考察基体改进剂用量、灰化温度、原子化温度、基体干扰以及共存离子干扰对测定结果的影响,确定最佳测定条件:以硼含量为1000 mg/kg的硼酸为背景基体,加入适量甘露醇,样品作酸化处理,灰化温度为1700℃,原子化温度为2450℃。钙含量在8~32 μg/kg范围内与光谱强度成良好的线性关系,相关系数为0.9996,方法检出限为1.79 μg/kg。对于硼基体含量为0~2500 mg/kg的样品,测定结果的相对标准偏差为0.5%~7.5%(n=6),相对误差不大于13.2%,加标回收率为93.9%~113.3%。该方法检测速度快,结果准确,能满足实际生产要求。     

Determination of Ascorbic Acid,Total Ascorbic Acid,and Dehydroascorbic Acid in Bee Pollen Using Hydrophilic Interaction Liquid Chromatography-Ultraviolet Detection

Ascorbic acid (AA) is one of the essential nutrients in bee pollen, however, it is unstable and likely to be oxidized. Generally, the oxidation form (dehydroascorbic acid (DHA)) is considered to have equivalent biological activity as the reduction form. Thus, determination of the total content of AA and DHA would be more accurate for the nutritional analysis of bee pollen. Here we present a simple, sensitive, and reliable method for the determination of AA, total ascorbic acids (TAA), and DHA in rape (Brassica campestris), lotus (Nelumbo nucifera), and camellia (Camellia japonica) bee pollen, which is based on ultrasonic extraction in metaphosphoric acid solution, and analysis using hydrophilic interaction liquid chromatography (HILIC)-ultraviolet detection. Analytical performance of the method was evaluated and validated, then the proposed method was successfully applied in twenty-one bee pollen samples. Results indicated that contents of AA were in the range of 17.54 to 94.01 µg/g, 66.01 to 111.66 µg/g, and 90.04 to 313.02 µg/g for rape, lotus, and camellia bee pollen, respectively. In addition, percentages of DHA in TAA showed good intra-species consistency, with values of 13.7%, 16.5%, and 7.6% in rape, lotus, and camellia bee pollen, respectively. This is the first report on the discriminative determination between AA and DHA in bee pollen matrices. The proposed method would be valuable for the nutritional analysis of bee pollen.     

液相色谱-串联质谱法测定花粉中的链霉素和双氢链霉素

建立了花粉中链霉素（streptomycin,STR）与双氢链霉素（dihydrostreptomycin,DHS）的高效液相色谱-串联质谱（HPLC-MS/MS）检测方法。样品经提取液提取、三氯甲烷沉淀蛋白后,用C18固相萃取柱进行富集净化,采用HPLC-MS/MS对目标物进行定性确证和定量分析。在Protemix WCX-NP5色谱柱（100 mm×2.1 mm,5 μm）上以5%（v/v）甲酸、20 mmol/L醋酸铵和甲醇为流动相进行梯度洗脱分离;质谱采集模式为电喷雾正离子监测模式。链霉素和双氢链霉素的检出限（以信噪比（S/N）=3计）均为5 μg/kg,定量限（以S/N=10计）均为10 μg/kg;在10~200 μg/L的质量浓度范围内呈现良好的线性关系,相关系数（r）大于0.99。本底空白的松花粉、玉米花粉、茶花粉、葵花粉、油菜花粉、杂花粉等6种基质中10、20、50 μg/kg添加水平下的加标回收率范围为76.8%~100.3%,精密度范围为3.70%~12.6%。该方法无需使用对LC-MS联用仪容易造成污染的七氟正丁酸,且方法准确可靠,适用于大部分花粉基质的测定。     

Determination of chloramphenicol residues in bee pollen by liquid chromatography/tandem mass spectrometry

A novel liquid chromatographic/tandem mass spectrometric (LC/MS/MS) method was developed for the trace residue determination of chloramphenicol (CAP) in bee pollen. CAP was extracted from bee pollen with a mixture of methanol and 1% metaphosphoric acid solution, followed by a 2-stage solid-phase extraction enrichment and cleanup. The first stage involved a polymeric cartridge, and the second stage involved an alumina neutral cartridge. The LC separation was performed on a C18 column with 10 mM ammonium formate-acetonitrile (7 + 3) as the mobile phase and MS detection with negative-ion electrospray ionization. CAP-d5 was used as the internal standard. The method was validated according to Commission Decision 2002/657/EC. The calibration curves were linear between 0.1 and 5.0 ng/mL, and overall recoveries ranged from 98 to 113%. Decision limits (CCalpha) ranged from 0.05 to 0.07 microg/kg, and detection capabilities (CCbeta) ranged from 0.08 to 0.12 microg/kg. The developed method was applied to 11 samples.     

液相色谱-串联质谱法测定蜂产品中吡虫啉及其3种代谢物

建立了蜂蜜和蜂花粉中吡虫啉及其代谢物吡虫啉烯烃、吡虫啉脲、6-氯烟酸的液相色谱-串联质谱(LC-MS/MS)检测方法.在QuEChERS方法基础上,针对目标物化学性质和样品杂质情况,对提取溶液的pH值、提取次数、净化材料等参数进行了优化.最终以5％甲酸-乙腈溶液提取两次,无水MgSO4、NaCl盐析分层,提取液经增强型脂类去除材料(EMR)净化,以LC-MS/MS进行测定,基质外标法进行定量分析.结果表明,蜂蜜和蜂花粉中吡虫啉、吡虫啉烯烃、吡虫啉脲、6-氯烟酸的平均加标回收率为86.0％～111.5％, 相对标准偏差在1.7％～9.6％之间, 检出限分别为0.20, 3.50, 0.40和14.00 μg/kg,定量限分别为0.60, 11.64, 1.20和45.00 μg/kg.本方法分析速度快、灵敏度高、重现性好,适用于蜂蜜和蜂花粉中吡虫啉及其3种代谢物的快速测定.     

Screening of Plant Pollen Sources,Polyphenolic Compounds,Fatty Acids and Antioxidant/Antimicrobial Activity from Bee Pollen

In this study, the botanical origin, total flavonoid and phenolic content, antioxidant activity, phenolic profile and fatty acid composition of mixed bee pollen loads collected in Bayburt, Turkey, were determined. In addition to these assays, antibacterial activity of bee-collected pollen extract (BCPE) against a variety of food-borne pathogenic bacteria was determined in vitro. Pollen loads were classified into five botanical families based on their color: Asteraceae, Fabaceae, Campanulaceae, Cistaceae and Rosaceae. Total flavonoid, total phenolic, CUPRAC and CERAC concentrations were 173.52 mg GAE/g, 79.21 mg QE/g, 85.59 mg Trolox/g and 118.13 mg Trolox/g, respectively. Twenty-three phenolic compounds were scanned in bee pollen extract by LC-MS/MS, with rutin being the most abundant. Cis-4,7,10,13,16,19 docosahexaenoic acid was the predominant fatty acid, followed by cis-11-eicosenoic acid, palmitic acid, and alfa linolenic acid. In addition, the agar well diffusion (AWD) and micro-broth dilution methods were used to determine of the antibacterial activity of the BCPE sample. MIC values were observed to vary between 2.5–5 mg/mL for Gram-positive bacteria and 5–10 mg/mL for Gram-negative bacteria. These findings indicate that bee pollen could be a potential source of antioxidants and antimicrobials.     

Volatile compounds composition and antioxidant activity of bee pollen collected in Lithuania

Characterization of volatile compounds composition and evaluation of antioxidant properties of bee pollen collected in Lithuania is presented in the paper, which is the first study on pollen of Lithuanian origin to our knowledge. Three polyfloral pollen samples collected by honey bees were analyzed. Characterization of volatile compounds was performed using solid phase microextraction (SPME) and GC-MS. Styrene was predominant in all samples contributing 19.6–27.0 mass %. Sample A distinguished by a high amount of limonene, 9.0 mass %, sample B differed from the rest by a high content of hexanal, 9.3 mass %, and nonanal, 12.3 mass %, while sample C showed the highest content of 1-tridecene, 43.3 mass %. Screening of antioxidant properties was carried out by spectrophotometric methods and liquid chromatography coupled with a post-column 1,1-diphenyl-2-picrylhydrazyl (DPPH) reaction detector and electrochemical detector. Total phenolic and flavonoid contents together with radical scavenging activity in the free radical (DPPH) model system were evaluated in the tested samples. Total phenolic content varied from 24.4 mg g^?1 to 38.9 mg g^?1, total flavonoid content was in the range of 7.3–10.0 mg g^?1 and radical scavenging activity was found between 30.7 mg g^?1 and 34.9 mg g^?1, all data are expressed in rutin equivalents. To process the collected data statistically and classify the bee pollen samples to clusters according to their volatile composition and antioxidant activity, principal component analysis, hierarchical cluster analysis and non-linear discriminant analysis were applied.     

Determination of tryptophan in bee pollen and royal jelly by high‐performance liquid chromatography with fluorescence detection

A method for tryptophan analysis in bee pollen and royal jelly was developed using HPLC with fluorescence detection. To determine the free tryptophan in bee pollen and royal jelly, ultrasonic extraction was performed using water (pH 6.3)–acetonitrile (10:1, v/v) as extraction solvent. While determining the total tryptophan in these bee products, the method involves alkaline hydrolysis of the proteins with 4 mol/L sodium hydroxide at 110°C for 20 h under anaerobic conditions. The operating conditions for the HPLC analysis were: Symmetry C₁₈ column (4.6 × 250 mm, 5 µm), 0.1% trifluoroacetic acid–methanol (75:25, v/v) as the mobile phase at a flow rate of 1.0 mL/min at 30°C. The fluorescence detector was operated at an excitation wavelength of 280 nm and an emission wavelength of 340 nm. A linear response (r² > 0.9998) was obtained in the range 0.0625–5.0 µg/mL. The method was successfully applied to the determination of the free and total tryptophan contents in bee pollens, which were 0.069 ± 0.003 and 2.693 ± 0.476 mg/g, respectively, while only the total tryptophan was detected in royal jelly, with a content of 1.743 ± 0.066 mg/g. Copyright © 2009 John Wiley & Sons, Ltd.     

Use of NIRS technology with a remote reflectance fibre-optic probe for predicting major components in bee pollen

In the present work, we study the use of near infra-red spectroscopy (NIRS) technology together with a remote reflectance fibre-optic probe for determination of the major components in bee pollen. The method allows immediate control of the bee pollen without prior sample treatment or destruction through direct application of the fibre-optic probe to the sample.The regression method employed was modified partial least squares (MPLS). The calibration results obtained using 45 samples of bee pollen allowed the measurement of protein, moisture, ash, reducing sugars, and pH with multiple correlation coefficients (RSQ) and prediction corrected standard errors (SEPC) of 0.91, 0.56% for protein, of 0.78 and 0.49% for moisture; 0.92 and 0.049% for ash; 0.81 and 1.32 g of glucose/100 g of bee pollen; 0.84 and 0.15 for pH, respectively.The prediction capacity of the pattern was checked by applying it to samples of unknown pollen in external validation.