3. Comprehension

a. Read the text and answer the questions in your own words.

1. Why analytical chemistry is subdivided?

2. What do analytical and physical chemistry have in common?

3. Which methods are called classical? What are they?

4. What modern analytical techniques are mentioned in the article?

5. How new techniques might be helpful in the future?

b. Match the words with their definitions.

1. Sample A. an instrument used for doing special jobs

2. Overlap B. to take liquids

3. Tool C. as much as is needed for a purpose

4. Emit D. to cover partly and go beyond it

5. Absorb E. a small part representing the whole

6. Analyte F. of noticeable importance

7. Reagent G. chemical substance

8. Sufficient H. the measure of the amount of a substance in a liquid

9. Concentration I. to send out

10. Significant J. substance that shows the presence of another

substance in a compound

4. Reading

Text B

a. Read the text and fill in the numbered gaps with suitable sentences.

1. The next step is sample preservation.

2. Once the sample preparation is complete, the analysis is carried out by an instrument of choice.

3. It could be the chemical or physical composition, structural or surface properties, or a sequence of proteins in genetic material.

4. The pesticides have to be extracted into a solution, which can be analyzed by an instrument.

5. It is obvious that an error in the first three steps cannot be rectified by even the most sophisticated analytical instrument.

The measurement process

The purpose of an analytical study is to obtain information about some object or substance. The substance could be a solid, a liquid, a gas, or a biological material. The information to be obtained can be varied.1__________________. Despite the sophisticated arsenal of analytical techniques available, it is not possible to find every bit of information of even a very small number of samples. For the most part, the state of current instrumentation has not evolved to the point where we can take an instrument to an object and get all the necessary information. Although there is much interest in such noninvasive devices, most analysis is still done by taking a part of the object under study and analyzing it in the laboratory or at the site. Some common steps involved in the process are shown below.

1.Sampling		2.Sampling preservation		3.Sample preparation		4.Analysis

The first step is sampling, where the sample is obtained from the object to be analyzed. This is collected such that it represents the original object. Sampling is done with variability within the object in mind. For example, while collecting samples for determination of Ca ²⁺in a lake, it should be kept in mind that its concentrations can vary depending on the location, the depth, and the time of year. 2.___________This is an important step, because there is usually a delay between sample collection and analysis. Sample preservation ensures that the sample retains its physical and chemical characteristics so that the analysis truly represents the object under study. Once the sample is ready for analysis, sample preparation is the next step. Most samples are not ready for direct introduction into instruments. For example, in the analysis of pesticides in fish liver, it is not possible to analyze the liver directly. 3._____________There might be several processes within sample preparation itself. Some steps commonly encountered are shown below.

1. Homogenization		2. Extraction		3. Concentration		4. Clean-up		5. Analysis

However, they depend on the sample, the matrix, and the concentration level at which the analysis needs to be carried out. For instance, trace analysis requires more stringent sample preparation than major component analysis.4.________________ A variety of instruments are used for different types of analysis, depending on the information to be acquired: for example, chromatography for organic analysis, atomic spectroscopy for metal analysis, capillary electrophoresis for DNA sequencing, and electron microscopy for small structures. The sample preparation depends on the analytical techniques to be employed and their capabilities. 5.______________ .So the importance of the prior steps, in particular the sample preparation, cannot be under stressed.

b. Complete the definitions below with the words: available, liver, to obtain, noninvasive, capability, variability, stringent, encounter, prior, employ.

1. To……………..means to get something.

2. If something is…………..it is easy of access.

3. ……………….is a large organ in the body which cleans blood.

4. ……………………means without any contact, hands free.

5. …….................is diversity or a range to choose from.

6. If you ………………..it means you come across or meet something.

7. ………………..means to be accurate or precise.

8. …………….means to apply or to use.

9. ……….is the quality of having the power or skills needed.

10. ………………….is located before.

Summarize the text above using the new vocabulary.

7. Video

a. Answer the following questions.

1. What is usually tested in microbiological laboratories?

2. What kind of service do you think clients expect from such laboratories?

3. Have you ever addressed to a microbiological laboratory? What can you say about the service? Did it meet all your reqirements?

4. Oder the most important factors for you: a) quality; b) reasonable prices; c) modern high quality equipment; d) quickness; e) knowledgeable and friendly stuff.

b. Watch the video advertising microbiological laboratory Microconsult, Inc and mark the sentences True or False.

1. Laboratory testing often lacks good customer service, quality and reasonable pricing. T/F

2. Bill Brine started Microconsult in 1996.T/F

3. Microconsult earned its reputation among clients by offering high quality of services and personal touch.T/F

4. The growth of the company depends on knowledgeable and friendly stuff with superior service.T/F

5. The company has grown ten-fold and has clients in over 25 sates.T/F

6. The moto of the company is “if we don’t service our clients someone else will help us”.T/F