Density of Liquinox and Alconox

Question:
What is the density of Liquinox and Alconox?

Answer:
Liquinox has a density of 1.07 g/ml.

Alconox is a dry blended hygroscopic powder, so its density varies as the powder settles and it gains or loses moisture. It is unusual to use the density of Alconox for anything because it varies. The typical density is 0.95 g/cu cm – the range is 0.85 g/cu cm to 1.1 g/cu cm – it varies with humidity, handling and settling.

Viscosity of Detojet

Question:
What is the viscosity of Detojet so a vendor can specify a flow meter for delivery application? Do you have any recommendations of methods of verification?

Answer:
The viscosity of Detojet is similar to that of water. The viscosity of water depends on temperature. At 293 K (20°C), the viscosity of water is 1.002 cP. Its viscosity decreases as temperature increases. Our studies show that Detojet passes thru a #1 Zahn cup in approximately 24 seconds at 24°C, approximately 10 cP.

Because of its high alkalinity, the presence of Detojet is always easily verified by pH.

Biochemistry Laboratory Cleaners

Question:
What cleaners are recommended for general biochemistry laboratory?

Answer:
For manual or soak cleaning of laboratory instruments, labware (glassware or plastics), vacuum equipment, tissue culture ware and sampling appartus soiled with grit, grime, slime, grease, oils, particulates, deposits, chemicals and solvents, we recommend using Liquinox. It is concentrated to save you money, phosphate free, biodegradable and is "free rinsing" meaning it leaves no interfering residue (which
is very important in the laboratory for reliable results!). We recommend that you monitor shifts in pH towards neutral as indicator to refresh an exhausted cleaning solution.

With regard to removing proteinaceous soils, tissue, blood and body fluids from glassware or plastics, we recommend using Tergazyme, a detergent that contains a protease enzyme. As with all of Alconox brand detergents, Tergazyme is concentrated to save you money, biodegradable, and free rinsing leaving no interfering residues (again, very important in the laboratory for reliable results!). We recommend that once in solution it be used within 3 to 6 hrs, due to the half life of the enzyme.
Pipets can be pre-soaked in Liquinox prior to cleaning. For the actual cleaning step we recommend Alcotabs be used in combination with syphon washer. Alcotabs are specially formulated tablets for slow release for maximum cleaning performance from your syphon pipette washers. Alcotabs are concentrated to save you money, biodegradable, and free rinsing to give you reliable results and no interfering residues. If you are testing for ALCOTABS® detergent, please adapt the procedure to use a detergent test kit that is sensitive to anionic detergent residues. These kits are available from:

1. Chemetrics Inc. water testing kit for anionic detergents, which is sensitive to 1/4 ppm. Contact Chemetrics, Inc. at 1-800-356-3072.

2. LaMotte Chemical water testing kit for anionic detergents, which is sensitive to 1 ppm. Contact LaMotte Chemical at 301-778-3100.

3. Hach Company water testing kit for anionic detergents, which is sensitive to 1 ppm. Contact Hach Company at 1-800-227-4224 or 303-669-3050.

Use the kits to test for detergent in rinse water that has passed through a pipette. If no detergent is detected with the kit, you can conclude that there is no interfering residue from the ALCOTABS®.
Alconox cleaners are available from leading lab supply dealers such as VWR Scientific, Thomas Scientific (800) 345-2100, Cole-Parmer (800) 323-4340, Spectrum Chemical (800) 772-8786 and USA Bluebook (800-548-1234); or check for a local dealer at www.alconox.com.

Cleaning Fiber Optics

Question:
Can you recommend a cleaner appropriate for fiber optics?

Answer:
To clean fiber optic components using ultrasonic tanks, use a warm (45 deg C) 1% Liquinox solution followed by a thorough high purity water rinse (distilled, deionized or best of all, reverse osmosis water). To clean manually, use 1% Liquinox with appropriate lint free swabs or tools to clean surfaces followed by rinse wiping and possibly drying with isopropyl alcohol (drying solvent). You can also use a drying solvent such as isopropyl alcohol after rinsing when you clean with ultrasonics, although it is not entirely necessary. Liquinox has emulsifiers that are effective on a broad range of oils, dispersants that are effective on particulates, and contains rinse-aids and anti-redeposition agents that allow it to rinse away freely without redepositing any residues.

Nonionic Detergent

Question:
What is a nonionic detergent? How can a nonionic detergent like Alcojet have ionic sodium salts in it? What does it mean when a mil spec requires the use of a nonionic detergent?

Answer:
Surfactants are surface active agents that are classified according to the charge on the organic part of the molecule. The surfactants are either: negatively charged which are anionic; positively charged which are cationic; neutrally charged which are nonionic; change charge with change in pH which are amphoteric; or in unusual cases the surfactant has both anionic and nonionic charges present on two parts of the molecule at once which are zwitterionic. So surfactants can be anionic, cationic, nonionic, amphoteric, or zwitterionic. In some cases, people somewhat ambiguously use the word detergent interchangeably with the word surfactant, so by the same logic when you are using the word detergent to mean surfactant, you can also say that there are anionic, cationic, nonionic, amphoteric and zwitterionic detergents. A less ambiguous definition for the word detergent is to use it to mean a blended product that contains a surfactant(s) plus other ingredients (typically called builders) to make a formulated detergent. By naming convention in the detergent industry, a formulated detergent is classified by the charge on the surfactant that is present in the detergent. You can also have formulated detergents that are anionic, cationic, nonionic, amphoteric and zwitterionic. These formulated detergents can contain builders such as sodium phosphates, sodium silicates, sodium carbonates, potassium hydroxide, citric acid and many other ionic salts or acids. So as you can see, it is perfectly possible to have a formulated detergent that is nonionic, yet contains many ions: both anionic and cationic. Understanding this possibility can be very important for electronic component cleaning where in some cases the use of nonionic detergents is specified. In many cases the intent of this nonionic specification is intended to assure that the detergent does not contain any metal ions that could deposit and leave a conductive residue. Many anionic surfactants have sodium or potassium metal ions present in their salt form when found in the detergent. For this reason, it is reasonable to consider not using anionic surfactants and anionic formulated detergents to avoid the possibility of depositing any sodium or potassium conductive metal salts in the event that the detergent evaporates on to the surface. In an effort to achieve this specification, it is often written as “the use of nonionic detergents”. Unfortunately, this can lead to the use of nonionic formulated detergents that contain many sodium and potassium metal ions that come from the builders in the formulated detergent. If these metal ion containing nonionic formulated detergents evaporate on to the surface during cleaning, they can result in conductive residue, even though a nonionic formulated detergent was used. To avoid this problem, when cleaning an electrical substrate where the cleaning specification calls for the use of a nonionic detergent, it is best to use a nonionic detergent that is ion-free. In this way you can assure that there are no metal ions coming from the builders in the nonionic formulated detergent. Alconox, Inc. supplies Detergent 8 which is both a nonionic detergent and an ion-free detergent.

Shelf Life of Liquinox

Question:
What is the shelf life of the Liquinox concentrate?

Answer:
Liquinox conforms to its 2 years from date of manufacture shelf life as long as the bottle is kept closed in between use. Incidental opening and closing of the bottle to pour out liquid for use, and the resulting increased head space air in the bottle or drum will not harm the shelf life. The main mechanisms of degradation are not related to air concentration above the Liquinox as long as there is not continual exchange of air in a completely open bottle such that continual evaporation is occurring.

Maximum Wash Temperature for Liquinox

Question:
What is the maximum wash temperature for Liquinox? At this maximum temperature is there an accelerated breakdown of detergent?

Answer:
Liquinox is heat stable all the way to boiling at standard temperature and
pressure conditions. From a practical standpoint, there are some detergency
mechanisms that begin to break down mechanistically as you approach boiling.
Emulsions begin to become less stable as you approach within a couple
degrees of boiling. If emulsifying is not a critical cleaning mechanism,
this may not be relevant to you. Maintaining a hot temperature and keeping
water from evaporating is also a practical consideration as far as maximum
temperature is concerned. As you approach boiling, the rates of evaporation
of water increase and it becomes more important to add make-up water in
order to maintain a controlled concentration of Liquinox. It is also of
course energy intensive to maintain a near boiling solution. As you
approach boiling, corrosion mechanisms are at their peak, so sometimes it
does not pay to approach boiling temperatures from a substrate stability
standpoint. From a practical standpoint, you would not typically use
Liquinox much above 95 deg C (200 deg F). With that said, there are unique
applications we are aware of that employ boiling Liquinox for small parts
washing, i.e. used in jewelry making where parts are dipped into a pot of
boiling Liquinox and the end user has to periodically add make-up water to
compensate for water evaporation.

Stability of Alconox

Question:
Is a 1% Alconox solution stable in tap water? How long can 1% Alconox be
stored as solution? Is pH measurement the best estimate of stability?

Answer:
Alconox is stable in tap water (or any purity water) for at least three
weeks when stored in a closed container. The mechanisms of degradation are
microbial activity and hydrolysis of the polyphosphates. We have done
studies that demonstrate that under closed lid (only) conditions for three
weeks, no microbial growth occurred. However for real life application, the
lid will be opened and closed to dispense the 1% Alconox, so you must
account for possible microbial growth. The best way to do that is to
monitor the pH of the solution over the course of the three week storage.
Take and record a pH start point after initially preparing the solution as a
reference point. Typically a drop in pH will detect the onset of microbial
proliferation and activity. Also, another early warning sign of microbial
activity is a "characteristic" microbial odor. Monitoring with pH and odor
during the three weeks will give you some control to be sure that microbial
activity had not started to cause concern.

The second possible mechanism is polyphosphate degradation. Detecting the
onset of polyphosphate hydrolysis is a little trickier than detecting
microbial growth. Unfortunately the pH only rises slightly as the
polyphosphates hydrolyze to ortho-phosphates, and to the best of our
knowledge there is no quick and simple way to monitor this. Though it is in
our experience that not a sufficient amount of polyphosphate hydrolysis
occurs during the first three weeks to perturb or interfere with
performance. So as long as you change the solution every three weeks, there
will be little concern other than possible microbial growth.