Urine preservatives - specimen collection, Mechanical Engineering

Assignment Help:

Urine preservatives - Specimen collection:

Urine preservatives: preservatives have different roles but are usually added to reduce bacterial action or chemical decomposition or to solubilize constituents that might otherwise precipitate out of solution. Another application is to decrease atmospheric oxidation of unstable compounds. Some specimens should have no preservative added because of possibility of interference with analytical methods. One of the most satisfactory forms of preservation of urine specimens is refrigeration immediately after collection. Urine preservative tablets contain many compounds that act on decreasing the pH of the urine or releasing of formaldehyde. Formalin is also used, but in large amounts it precipitate urea and inhibit certain reactions.

Acidification below pH 3 is widely used to preserve 24 hr urine specimens and is particularly useful for specimens for calcium, steroid, vanillylmandelic acid (VMA) determination (10 ml of HCl, 6 mol/L, per 24 hr excretion).

Sulfamic acid (10 g/L urine) is also used to educe pH. Boric acid ( 5 mg/30 ml) has been also used During acidification, precipitation of urates will occur, thereby rendering a specimen unsuitable for measurement of uric acid. Although thymol and chloroform were widely used in the past to preserve specimens for chemical and microscopic examination. Toluene is the only organic solvent that is still in use as a preservative. A mild base, such as sodium bicarbonate or small amount of NaOH, is used to preserve porphyrins, urobilinogen, and uric acid. When timed collection is complete, the specimen should be delivered without delay to the laboratory.

 


Related Discussions:- Urine preservatives - specimen collection

Gasket installation in module site installation, Q. Gasket Installation in ...

Q. Gasket Installation in Module site installation? Gasket will be installed after modules are set. Normally RTJ flanges require mating flanges to be spread with jacks and then

Capp for machining process, CAPP for Machining Process This explained ...

CAPP for Machining Process This explained mainly two different approaches to Computer Aided Process Planning, i.e.  (a) Variant approach, and  (b) Generative approach.

Scope of work for a project in mechanical engineering, Q. Scope of work for...

Q. Scope of work for a project in Mechanical Engineering? The Mechanical Engineering scope of work for a project involves the design and specification of mechanical equipment a

Determine radial and hoop stress, A hydraulic pipe is 20 cm internal diamet...

A hydraulic pipe is 20 cm internal diameter and 5 cm thick. It is needed to sustain an intensities of radial and hoop stress at several radii and plot their variation.

Chemical machining., chemical milling is used in aircraft plant to create p...

chemical milling is used in aircraft plant to create pockets in wing sections made of an aluminium alloy. the starting thickness of one work part is 20 mm.a series of rectangular s

What is injection moulding, Q. What is Injection moulding? An important...

Q. What is Injection moulding? An important industrial method of producing articles of thermoplastics is injection moulding. The moulding material is loaded into a hopper from

Plate shift drum stopper bolt and arm comp, Plate shift drum stopper bolt a...

Plate shift drum stopper bolt and arm comp Shift drum stopper : Ensure that the plate shift drum bolt is tight and in arm shift drum stopper assembly, check stopper arm bolt for to

Organisation set-up - construction of railway line, Organisation set-up: ...

Organisation set-up: The civil engineering department of the Railways is responsible for the maintenance of railway lines. The maintenance organisation consists of Chief Engi

Special casting methods, Special Casting Methods: 1. Die casting : D...

Special Casting Methods: 1. Die casting : Die casting is a permanent mould casting techniques in which molten metal is forced in the mould cavity under a pressure of 700 to

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd