基于固相基质分散的高效液相色谱-串联质谱法测定茄科蔬菜及其制品中龙葵素的含量

目的建立高效液相色谱-串联质谱法测定茄科蔬菜及其制品中龙葵素α-茄碱和α-卡茄碱含量。方法样品采用0.1%甲酸水溶液:乙腈=1:1(V:V)提取,C18固相基质分散净化,经过色谱柱BEHAmide (2.1mm×100 mm, 1.7μm)分离,以2 mmol/L乙酸铵的0.1%甲酸水溶液:2 mmol/L乙酸铵的乙腈溶液为流动相进行梯度洗脱,柱温40℃,流速0.4m L/min,多反应模式监测,外标法定量。结果α-茄碱和α-卡茄碱在5～1000ng/m L内线性关系良好(r20.999)。α-茄碱方法检出限和定量限范围分别为0.1～1 mg/kg, 0.3～3 mg/kg;α-卡茄碱检出限和定量限分别为0.03～0.3 mg/kg, 0.1～1 mg/kg;在低、中、高3水平添加下,α-茄碱回收率为90.7%～108.0%,α-卡茄碱回收率为89.8%～102.7%,相对标准偏差均小于5.6%(n=6)。结论本方法快速简便、准确度好、灵敏度高等特点,适用于大批量茄科蔬菜及其制品中α-茄碱和α-卡茄碱的测定。     

气相色谱法测定茄果类蔬菜中12种有机磷类农药残留

目的建立气相色谱法同时测定茄果类蔬菜中12种有机磷类农药的残留分析方法。方法样品用乙腈提取、旋蒸后经有机微孔滤膜净化,采用DB-1701毛细管色谱柱程序升温分离,采用火焰光度检测器(flame photometric detector,FPD)测定。结果在本试验条件下,12种有机磷类农药分离效果较好,在0.05～1.0 mg/L范围内呈现良好的线性关系,相关系数r值为0.99935～0.99993,回收率为71.5%～112.4%,RSD值为1.0%～9.4%,检出限为0.01～0.06 mg/kg。结论该方法快速、准确,适合茄果类蔬菜中多种农药残留定量检测要求。     

6种茄果类蔬菜中多环芳烃分布特征及健康风险评估

目的 研究多环芳烃(polycyclic aromatic hydrocarbons,PAHs)在茄果类蔬菜中的分布特征和积累规律,并对南宁市不同人群摄食茄果类蔬菜的健康风险进行评估。方法 以番茄、茄子、辣椒为研究对象,采用高效液相色谱法测定PAHs含量,分析番茄、紫茄子、黑茄子、彩椒、线椒、指天椒6种茄果类蔬菜中的PAHs组成,并针对3个辣椒品种进行PAHs含量动态分析以及不同器官组织的PAHs差异分析。结果 6种茄果类蔬菜中PAHs的含量范围为525.03～1216.14 μg/kg,大小依次为指天椒>线椒>紫茄子>彩椒>黑茄子>番茄,不同品种间∑16 PAHs存在显著性差异;各苯环数PAHs含量占比大小为3环>4环>5环>6环>2环。随着采摘时间的推迟,辣椒果实∑16 PAHs含量呈逐渐升高趋势。∑16 PAHs在辣椒不同器官部位富集规律为果实>根>叶片>茎,各部位PAHs含量的差异达到显著性水平。健康风险分析表明,南宁市居民摄食茄果类蔬菜终生致癌风险值为9.73×10^-7～8.84×1...     

蚯蚓粪基质对茄果类蔬菜穴盘苗耐热性的影响

为深入了解蚯蚓粪基质茄果类蔬菜穴盘苗的耐热性,以常规草炭系基质为对照,测定了番茄、茄子、辣椒穴盘苗叶片叶绿素含量、抗氧化酶(SOD、POD、CAT)活性、电解质渗出率和丙二醛(MDA)含量等指标。结果表明:高温胁迫下对照叶绿素总量降低幅度较大,比蚯蚓粪基质穴盘苗提高3.13%～246.02%;蚯蚓粪基质穴盘苗在高温胁迫下叶片抗氧化酶活性增强,对照抗氧化酶活性有所减弱;高温胁迫下对照穴盘苗叶片电解质渗出率和MDA含量增加幅度较大,分别比蚯蚓粪基质穴盘苗提高20.21%～122.53%和13.88%～58.14%,说明蚯蚓粪基质茄果类蔬菜穴盘苗具有较强的耐热性。     

高效液相色谱-串联质谱法测定茄科蔬菜及其制品中α-茄碱和α-卡茄碱的含量

目的建立通过式固相萃取-高效液相色谱-串联质谱法同时测定茄科蔬菜及其制品中α-茄碱和α-卡茄碱含量的分析方法。方法样品采用1%甲酸水溶液:乙腈=1:1 (V:V)涡旋提取, Oasis? PRiME HLB固相萃取(solid phase extraction, SPE)柱净化,经过色谱柱BEH Amide (2.1 mm×100 mm, 1.7μm)分离,以2 mmol/L乙酸铵的0.1%甲酸水溶液(A):2mmol/L乙酸铵的乙腈溶液(B)为流动相进行梯度洗脱,柱温40℃,流速0.4 mL/min,多反应模式监测,基质匹配标准曲线外标法定量。结果在1~500 ng/mL范围内,α-茄碱和α-卡茄碱与峰面积线性关系良好(相关系数r2>0.998)。在低、中、高3个水平添加下,α-茄碱回收率为91.3%~104.6%,α-卡茄碱回收率为90.3%~108.4%,相对标准偏差不超过5.5%(n=6)。结论该方法快速简便、准确度好、灵敏度高,适用于大批量茄科蔬菜及其制品中α-茄碱和α-卡茄碱的快速测定。     

番茄、辣椒、茄子中甲基毒死蜱残留量测定

采用高效液相色谱-二极管阵列检测器对番茄、辣椒和茄子中甲基毒死蜱残留量进行测定。样品用乙腈提取后,经Carb/NH2固相萃取小柱净化,用C8液相色谱柱、二极管阵列检测器,对甲基毒死蜱残留量的测定可取得满意的结果。该方法样品平均加标回收率为80.7%～92.4%,相对标准偏差为1.1%～4.6%;蔬菜中甲基毒死蜱检出下限为0.02mg/kg。     

四川型蔬菜大棚节能高效的措施

四川盆地是我国日照最少的地区，蔬菜设施栽培难度较大．本文论述了发展寡日照地区蔬菜设施栽培的主要措施，并提出了今后的发展方向。     

Colorado Potato Beetle Toxins Revisited: Evidence the Beetle Does Not Sequester Host Plant Glycoalkaloids

The Colorado potato beetle feeds only on glycoalkaloid-laden solanaceous plants, appears to be toxic to predators, and has aposematic coloration, suggesting the beetle may sequester alkaloids from its host plants. This study tested 4th instars and adults, as well as isolated hemolymph and excrement, to determine if the beetles sequester, metabolize, or excrete alkaloids ingested from their host plants. HPLC analysis showed: that neither the larvae nor the adults sequestered either solanine or chaconine from potato foliage; that any alkaloids in the beetles were at concentrations well below 1 ppm; and that alkaloids were found in the excrement of larvae at approximately the same concentrations as in foliage. Analysis of alkaloids in the remains of fed-upon leaflet halves plus excreta during 24 hr feeding by 4th instars, as compared to alkaloids in the uneaten halves of the leaflets, showed that equal amounts of alkaloids were excreted as were ingested. The aposematic coloration probably warns of a previously-identified toxic dipeptide instead of a plant-derived alkaloid, as the Colorado potato beetle appears to excrete, rather than sequester or metabolize, the alkaloids from its host plants.