TACN eclassroom

Choose the correct definition of "Triplicate"

• the time that a solute spends in a column

• to measure small mass in the sub-milligram range

• to make three repeats of (something)

• to remove (an adsorbed substance) by washing with a solvent, especially in chromatography

Choose the correct definition of "Solid-phase extraction"

• a type of graph used as a quantitative research technique

• a phase over which the mobile phase passes in the technique of chromatography

• a technique designed for rapid, selective sample preparation and purification prior to the chromatographic analysis

• a device or instrument designed to detect the presence of a particular object or substance and to emit a signal in response

What is the name of CH3OH

• Acetone

• Acetonitrile

• Methanol

• Ethanol

Which characteristic is different between the "reversed-phase" HPLC and "normal-phase" in terms of stationary and mobile phases

• Polarity

• Density

• Mass

• Volume

The meaning of word "expressed" in the following sentence: "Using the mean values determined in Step 5 above, calculate the concentration of caffeine in your sample expressed in terms of milligrams caffeine in a 12-oz. can (1 ml = 0.0338 oz) using the standard curve based on peak height"

• Biểu diễn

• tính toán

• làm tròn

• ý nghĩa khác

The meaning of word "volatile" in the following sentence: "Unlike gas chromatography, it is not necessary for the compound being analyzed to be volatile."

• bay hơi

• tan

• phân cực

• không phân cực

Choose the correct definition of "Elute"

• the time that a solute spends in a column

• to measure small mass in the sub-milligram range

• make three repeats of (something)

• to remove (an adsorbed substance) by washing with a solvent, especially in chromatography

Choose the correct definition of "Detector"

• a type of graph used as a quantitative research technique

• a phase over which the mobile phase passes in the technique of chromatography

• a technique designed for rapid, selective sample preparation and purification prior to the chromatographic analysis

• a device or instrument designed to detect the presence of a particular object or substance and to emit a signal in response.

Fill in the missing word for (5):Food analysis methods are built around high-performance liquid chromatography, which has proven to be an optimal technology for detecting and/or (1)……… the vast majority of food analytes. These methods employ a stepwise approach that first removes the sample (2) ….., then isolates the analytes of interest and individually resolves them on a (3)…… column. The efficiency of the (4)…….. depends on, among other things, the differential interaction of analytes of interest with both mobile and column stationary phases. Of course, classifying food analytes according to their relative volatility and (5)……. are factors that must be considered when selecting an appropriate analytical method for their determination.

• polarity

• mass

• conductivity

• hardness

Fill in the missing word for (3):Food analysis methods are built around high-performance liquid chromatography, which has proven to be an optimal technology for detecting and/or (1)……… the vast majority of food analytes. These methods employ a stepwise approach that first removes the sample (2) ….., then isolates the analytes of interest and individually resolves them on a (3)…… column. The efficiency of the (4)…….. depends on, among other things, the differential interaction of analytes of interest with both mobile and column stationary phases. Of course, classifying food analytes according to their relative volatility and (5)……. are factors that must be considered when selecting an appropriate analytical method for their determination.

• chromatographic

• chromatography

• analysis

• analytically