柱前衍生高效液相色谱法测定面制品中溴酸盐的含量

针对目前离子色谱电导法检测面制品中溴酸盐的假阳性问题,建立柱前衍生高效液相色谱测定面制品中的溴酸盐的方法。面制品经超纯水提取、过滤、衍生,采用C18色谱柱,紫外检测器检测。结果表明,采用亚铁氰化钾-乙酸锌作为沉淀剂,待测液在45℃时衍生60 min,溴酸盐浓度在0.025¹ mg/L范围内与峰面积呈现良好线性关系,方法的加标回收率为87.90%⁹4.80%,检出限为0.3 mg/kg,定量限为1 mg/kg。与离子色谱法相比,该方法具有干扰少,灵敏度高,成本低等优点,可很好地满足面制品中溴酸盐的检测和质控要求。      

2种方法检测食品模拟物中矿物油含量的比较研究

目的 考察离线固相萃取-气相色谱-氢火焰离子化检测器法(off-line solid phase extraction-gas chromatography-flame ionization detector,off-line SPE-GC-FID)与高效液相色谱-气相色谱-氢火焰离子化检测器在线联用法(on-line...     

无蔗糖冷冻饮品中蔗糖的测定

目的建立一种测定无蔗糖冷冻饮品中的蔗糖含量的高效液相色谱蒸发光散射法。方法无蔗糖冷冻饮品经乙腈提取其中蔗糖,离心沉淀杂质后采用液相色谱-蒸发光散射法进行检测。结果蔗糖质量浓度在0.1~0.5 g/L范围内标准曲线的相关系数r20.99,在质量分数为0.2、0.4、1.0 g/100 g三个加标水平下,方法回收率为93.5%~99.5%,相对标准偏差为1.8%~3.4%。结论该方法简便、快速、实用、准确,各项技术指标满足国内外法规的要求,适用于无蔗糖冷冻饮品中蔗糖的检测。     

HPLC-DAD法测定馒头中喹啉黄、食用绿S和亮绿3种色素含量的研究

建立了高效液相色谱(HPLC)串联紫外器(DAD)测定馒头中3种色素含量的方法。以无水乙醇—氨水—水(7:2:1)溶液作为提取溶剂,用超声辅助提取样品中的色素,用HPLC-DAD进行检测,检测波长425 nm、624 nm,色谱柱为PAK CAPCELL C_(18)(5μm,4.6×200 mm),流速1.0 mL·min~(-1),柱温35℃,以甲醇-乙酸铵溶液为流动相进行梯度洗脱。结果表明:3种色素分离度较好,具有良好的线性关系(r=0.999 9),重现性、精密度良好(RSD%均小于3%),检出限食用绿S为0.848 4 ng、喹啉黄为6.833 9 ng、亮绿为1.336 0 ng,平均加标回收率为91%~105%。该方法简单、快速、灵敏度高、回收率高、检出限低,适用于馒头中喹啉黄、食用绿S、亮绿含量的测定。     

两种分析塑料食品包装材料中抗氧化剂的方法

采用气相色谱/氢火焰离子化法(GC/FID)和高效液相色谱/二极管阵列法(HPLC/DAD)分别对塑料食品包装材料中BHA、BHT、TBHQ三种酚类抗氧化剂进行定性定量分析。分别用正己烷及乙腈超声提取塑料食品包装材料中抗氧化剂,并对超声提取时间、次数及温度进行优化。结果表明:在本试验条件下,抗氧化剂添加量为6~30mg/kg范围内,气相色谱法测定BHA、BHT、TBHQ三种成分的平均添加回收率分别为95.8%~97.2%、93.1%~96.3%、91.5%~95.8%;相对标准偏差分别为1.55%~2.38%、1.95%~2.60%、2.35%~3.14%;检出限分别为0.40、0.32、0.72mg/kg。高效液相色谱法测定BHA、BHT、TBHQ三种成分的平均添加回收率为94.5%~96.2%、90.5%~93.7%、88.2%~91.6%;相对标准偏差分别为1.87%~2.58%、2.05%~2.72%、2.62%~3.38%;检出限分别为0.30、1.25、0.90mg/kg。两种方法皆准确、灵敏、重现性好,适用于塑料食品包装材料中抗氧化剂的检测。     

气相色谱法测定皮革废水技术改进的研究

本文采用降低热导池检测器(TCD)内压强的方法，成功解决了气相毛细管柱与TCD联用的难题。设计了适合于毛细管柱联用的TCD。通过对制革废水的测定证明了该技术具有更快速、准确、高效的优点。     

小麦不完善粒快速检测仪器研究(Online First, Recommended Article)

采用图像分析技术与自动控制技术,将人工智能技术应用于小麦不完善粒检测,研究开发了小麦不完善粒指标的自动快速无损检测仪器。通过验证该仪器检测小麦不完善粒的准确性、重复性、稳定性、台间差等相关性能参数,结果表明：该仪器检测性能稳定,准确性、重复性、稳定性、台间差均符合行业标准要求,操作简单,检测速度快,克服了人工检测主观性强、重复性差、不同人员间检验一致性较差等问题,可实现小麦不完善粒的自动快速无损检测,能够满足粮食收储企业、加工企业和检测机构的检测需要。     

Acrylamide in Romanian food using HPLC-UV and a health risk assessment

The aim of this study was to investigate the level of acrylamide from coffee, potato chips and French fries in Romanian food. According to the European Food Safety Authority, coffee beans, potato chips and French fries have the highest levels of acrylamide. For this survey, 50 samples of coffee beans, 50 samples of potato chips and 25 samples of French fries were purchased from different producers from the Romanian market. Acrylamide levels have been quantified using high-performance liquid chromatography with a diode array detector (HPLC-DAD) method, using water as mobile phase. Health risk assessment was achieved by computing the average daily intake, hazard quotient, cumulative risk, carcinogenic risk and cancer risk. For coffee, potato chips and French fries, acrylamide was not shown to pose a health risk in Romanian food.     

磁动式测氧仪数据特性的分析

从磁动式测氧仪的工作原理,分析仪器中充氮哑铃球的扭转角度与氧含量的关系.利用居里定律,推导气体的体积磁化率随温度的变化公式.实验测出测氧仪中光点在CCD的像元值随氧气百分比及温度变化的规律,得出对定标和温度补偿数据的处理可采用二次曲线拟合;在不同温度点对CCD像元值长时间观测比较,得出仪器的校零应采用曲线平移方案处理.     

Development of a Bolometer Detector System for the NIST High Accuracy Infrared Spectrophotometer

A bolometer detector system was developed for the high accuracy infrared spectrophotometer at the National Institute of Standards and Technology to provide maximum sensitivity, spatial uniformity, and linearity of response covering the entire infrared spectral range. The spatial response variation was measured to be within 0.1 %. The linearity of the detector output was measured over three decades of input power. After applying a simple correction procedure, the detector output was found to deviate less than 0.2 % from linear behavior over this range. The noise equivalent power (NEP) of the bolometer system was 6 × 10⁻¹² W/Hz at the frequency of 80 Hz. The detector output 3 dB roll-off frequency was 200 Hz. The detector output was stable to within ± 0.05 % over a 15 min period. These results demonstrate that the bolometer detector system will serve as an excellent detector for the high accuracy infrared spectrophotometer.