Laboratory Workers

The locations of the tietriangle and biaodal curves ia the phase diagram depead oa the molecular stmctures of the amphiphile and oil, on the concentration of cosurfactant and/or electrolyte if either of these components is added, and on the temperature (and, especially for compressible oils such as propane or carbon dioxide, on the pressure (29,30)). Unfortunately for the laboratory worker, only by measuriag (or correcdy estimatiag) the compositions of T, Af, and B can one be certain whether a certain pair of Hquid layers are a microemulsion and conjugate aqueous phase, a microemulsion and oleic phase, or simply a pair of aqueous and oleic phases. 

By its nature, the present treatment is not exhaustive, nor do we claim that any of the methods taken from the literature are the best possible. Nevertheless, we feel that the information contained in this book is likely to be helpful to a wide range of laboratory workers, including physical and inorganic chemists, research students, biochemists, and biologists. We hope that it will also be of use, although perhaps to only a limited extent, to experienced organic chemists. 

In the past ten years laboratory workers have become increasingly conscious of safety in the laboratory environment. We have therefore in three places in Chapter 1 (pp. 3 and 33, and bibliography p. 52) stressed more strongly the importance of safety in the laboratory. Also, where possible, in Chapters 3 and 4 we draw attention to the dangers involved with the manipulation of some hazardous substances. 

Aides (administrative, data reduction, engineering, environmental health, laboratory, sanitarian, and unspecified), assistants (administrative, fiscal, laboratory, and legal), draftspersons, laboratory workers, mechanics, project illustrators, samplers, and technicians (air pollution control, air quality monitoring station, electronic, engineering, instrument, and unspecified). 

Connor, K.J., and McLintock, I.S. (1995) Radiation Protection Handbook for Laboratory Workers, H H Scientific Consultants. 

Many operations involving chemical reactions are potentially dangerous, and in such cases recommended procedures must be carefully followed and obeyed. All laboratory workers should familiarise themselves with local safety requirements (in some laboratories, the wearing of safety spectacles may be compulsory), and with the position of first-aid equipment. 

Research use of analytical results in the framework of a nonanalytical setting, such as a governmental investigation into the spread of pollution here, a strict protocol might exist for the collection of samples (number, locations, time, etc.) and the interpretation of results, as provided by various consultants (biologists, regulators, lawyers, statisticians, etc.) the analytical laboratory would only play the role of a black box that transforms chemistry into numbers in the perspective of the laboratory worker, calibration, validation, quality control, and interpolation are the foremost problems. Once the reliability and plausibility of the numbers is established, the statisticians take over. 

One research laboratory was located on the second floor of a building in which a diaper laundry occupied the first floor. The laundry equipment would periodically send veritable shock waves through the building, making many laboratory operations impossible for a short while. The laboratory workers referred to these annoying incidents as the times when the laundry dropped its load. ... 

Two types of office space are usually needed. One is the area where laboratory workers perform calculations, check proce-... 

The laboratory workers office space should be as close as possible to work areas and to fi equently used files. There should also be room for a typewTiter, if required. The work may be done on a separate desk or a section of desk-height work bench. 

Older laboratory workers could no doubt add many examples of their own to the list of unsafe practices. Modern laboratory planners and operators, however, are more aware of safety problems, and rules regarding safety have been made much more strict. It is up to the laboratory operator to become throughly familiar with such rules in order to organize and operate a safe laboratory. 

Mixing faucets are very convenient, though some laboratory workers prefer separate faucets for hot and cold water. Many like the aerators commonly used in kitchens, while others prefer faucets equipped with rubber or plastic hose. 

One laboratory used industrial-type brass valves for many of their water outlets, rather than the more expensive chrome plated ones available from the laboratory supply house. While their appearance was different, their performance was the same. To make the valves look better to both laboratory workers and visitors, the manager would occasionally treat them vdth metal polish. 

Universities and colleges operate placement services for their graduates, usually at no charge. College science students also malte excellent temporary or part-time laboratory workers while still going to school. They are eager to get experience in the field which will help them get a permanent job when they graduate. 

Each laboratory worker should be clearly instructed as to duties and responsibilities. A written job description outlining such mat-... 

C03-0142. Pure acetic acid, CH3 CO2 H, is 17.4 M. A laboratory worker measured out 100.0 mL of pure acetic acid and added enough water to make 500.0 mL of solution. A 75.0-mL portion of the acetic acid solution was then mixed with enough water to make 1.50 L of dilute solution. What was the final molarity of acetic acid in the dilute solution ... 

Because of the ubiquitous nature of FMs in consumer products, it is critical that any analytical chemistry laboratory measuring these compounds takes extra precautions to avoid laboratory contamination of samples. Several researchers [2,11,14-17] have pointed out that likely sources of FM contamination in the modern-day laboratory include the use of consumer products and fine fragrances by laboratory workers, fragrances in soaps used to clean glassware and the laboratory, and laboratory supplies such as gloves. 

Before beginning the analysis of FMs at low concentrations, the laboratory should analyze several laboratory blank samples to assess the degree to which the laboratory is contaminated. With every set of samples analyzed, the laboratory should also analyze a laboratory and field blank sample. Laboratory workers should be advised to be aware of their personal use of fragrance-enhanced consumer products and the potential for laboratory contamination. 

Yes. Vaccinia vaccine is recommended for laboratory workers who directly handle cultures, animals contaminated or infected with, nonhighly attenuated vaccinia virus, recombinant vaccinia viruses derived from nonhighly attenuated vaccinia strains, or other orthopoxviruses that infect humans. These would include monkeypox, cowpox, vaccinia, and variola. Other health-care workers, such as physicians and nurses whose contact with nonhighly attenuated vaccinia viruses is limited to contaminated materials such as medical dressings but who adhere to appropriate infection control measures, are at lower risk for accidental infection than laboratory workers. However, because a theoretical risk for infection exists, vaccination can be offered to this group. Vaccination is not recommended for people who do not directly handle nonhighly attenuated virus cultures or materials or who do not work with animals contaminated or infected with these viruses. 

A decrease in the amplitude of the sensory nerve action potential has also been observed in a group of 20 asymptomatic workers exposed to -hexanc (Pastore et al. 1994). The subjects of this study were selected on the basis of urinary levels of the n-hexane metabolite 2,5-hexanedione (See Sections 2.3 and 2.7) exceeding 5 mg/L and compared to a group of unexposed laboratory workers. Mean years worked was 8.13 (range, 1.5—23 years). Sensory and motor nerve conduction velocities and distal latencies were normal in all nerves tested. However, significant decreases were found in sensory nerve action potential amplitude in the median, sural, and ulnar nerves. Neither the level of 2,5-hexanedione in urine nor age correlated with the changes in amplitude however, there was a significant correlation between years worked and amplitude. 

Step 4 Ensure that control measures are used and maintained It is the responsibility of the employer to ensure that control measures are properly applied, and that all equipment is maintained in working order. For a procedure which is carried out repeatedly, it is necessary to carry out regular reassessment, usually on a yearly basis. This prevents laboratory workers from becoming complacent, and methods may change, quantities may increase, etc. 

We use the term programmable to describe the rational (and ideally, computer-aided and automated) approach to polysaccharide synthesis.20 To reduce the synthesis of complex carbohydrates to routine, we envision a four-step protocol (1) the sequence of interest is keyed into a computer, (2) the computer selects appropriate reagent combinations, (3) a laboratory worker (human or robotic) prepares the reagent... 

What does it mean to say that a laboratory worker has good analytical technique ... 

As indicated in Section 4.1 (and as should be apparent from the discussion thus far in this chapter), titrimetric analysis methods heavily utilize solution chemistry, and therefore volumes of solutions are prepared, measured, transferred, and analyzed with some degree of frequency in this type of analysis. It should not be surprising that analytical laboratory workers need to be well versed in the selection and proper use of the glassware and devices used for precise volume measurement. 

What are some realistic values of a correlation coefficient that would indicate to a laboratory worker that the error associated with his or her data is probably minimal ... 

A laboratory worker that has good analytical technique is one that takes special care in carrying out manual tasks to ensure that all data are obtained in a careful manner so that errors involved in handling samples and standards are eliminated or at least minimized. 

While the pieces of equipment mentioned above are now commonplace, it remains for the analysts to be well informed of potential dangers and of appropriate safety measures. To this end, we list below some safety tips of which any laboratory worker must be aware. This list should be studied carefully by all students who have chosen to enroll in an analytical chemistry course. This is not intended to be a complete list, however. Students should consult with their instructor in order to establish safety ground rules for the particular laboratory in which they will be working. Total awareness of hazards and dangers and what to do in case of an accident is the responsibility of the student and the instructor. 

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