7 Things to Consider When Ordering Cuvettes - eCuvettes

When you are a freshman about spectrophotometer or fluorometer experiments, you may get confused about cuvette selection, then you google ‘How to choose the right cuvette?’, almost all the answers show you the cuvette material is the most important thing because UV rays can’t go through most glass cuvettes but can go through the quartz cuvette.

If you are looking for more details, kindly visit our website.

Cuvettes on market usually manufactured from plastic, glass, quartz, there are different cuvette made from different materials below.

There are the most common types of cuvettes below, the materials they are manufactured from and their suitable wavelength:

1. Optical Glass Cuvettes
This cuvette material is suitable for the visible spectrum and has a decent transmission range from 340-2,500 nm.

2. UV Quartz Cuvettes
For UV-VIS absorbance studies, you absolutely need a UV quartz cuvette, if you cut corners here by getting a cheap glass or plastic cell, your data will be inaccurate, it’s not recommend to do.

3. IR Quartz Cuvettes
The transmission range on IR Quartz is 220nm to 3,500nm, it is a good choice for UV VIS measurements.

4. Polystyrene (PS) or Polymethyl Methacrylate (PMMA)
The transmission range on PS or PMMA quartz is 380nm to 780nm (Visible Spectrum). Most applications will fall in this range and many do not need the additional UV or IR points that you get from the other materials.

Glass and plastic materials are normally transparent to visible light (380-780 nm) but absorb in the UV (190 – 340 nm) wavelength ranges. Therefore, plastic and glass cuvettes are ideal for colorimetric protein assays or measurement of the bacterial culture density, but cannot be used for concentration and purity measurements of samples in the UV ranges.

It is important that the cuvettes have as high transmission as possible for certain measured wavelengths, but if you have a tight budget and only test the samples in Visible light, then you are going to want to go with a Plastic or Optical Glass cuvette. Plastic cuvettes are low-cost and disposable.

Cuvettes can be made of different materials, and they also can be assembled with different technics, such as Glued, Powder fused, or all fused.

If the sample is an aqueous solution, it can work with most plastic or glass or quartz cuvettes even the NRC glued cuvettes, then you can jump to cuvette type part directly; but if it is organic solvents, you’d better read the next Working Samples section first.

Working Samples

An ideal cuvette material would be transparent to the target light beam and does not interact with the samples used in the measurement.

The material from which the cuvette is made is relatively less important when the sample is an aqueous solution. Plastic or Glass or Quartz cuvettes will all work, and you can even use the most affordable URC glued cuvettes.

If the sample is organic solvents, it’s better to choose more robust cuvettes than the plastic ones, such as the Glass and Quartz cuvettes.

And you should go with chemical resistant fused (CRF) or high-temperature-resistant (HTR) versions rather than the non-resistant to chemicals (NRC) because the NRC cuvette is assembled with glue, benzene, ethanol, corrosive solutions, or other similar attribute solvents may cause the cuvette to leak because it degrades the bonds between the pieces.

2. Which kind of cuvette do you need, Spectrophotometer or Fluorescence cuvette?

It depends on the Laboratory Apparatus you will use.

Spectrophotometers Cuvettes are cells that have 2 parallel sides optical transparent. And the light beam comes in from the front window and exits the back window of the cuvette in one straight line.

The best-selling cuvettes for UV VIS Spectrophotometer measurements in our cuvettes line are our QS20-02, and QS37. Now QS20-02 and QS37 are pretty much identical. The only difference is that QS37 cells have square corners and Type 5 cells have rounded corners. Please see the photo below.

These cuvettes are the ultimate balance for someone looking for a high-quality UV quartz cuvette. You get the affordable full range of the UV quartz material, the price of $12.3 for QS is making it a great buy for labs on a budget.

There are some basic spectrophotometer quartz cuvettes, generally speaking, the rounded bottom one costs less than the square bottom one for the same cuvette type. And you can click here for more spectrophotometer cuvette.

Mingte are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.

Fluorescence cuvettes are cuvettes that have 4 optically polished walls (some specialized types of cuvettes have 3 transparent walls)

The most basic fluorescence quartz cell for UV VIS measurements is QS22-02. This cuvette has all four windows clear and comes in UV-grade quartz.

There are some basic fluorometer cells, like spectrometer cuvettes, a round bottom is also an alternative in our fluorescence line. And you can click here for more fluorometer cuvette.

3. What path length do you need?

The max path length you can use depends on the laboratory apparatus, and the other factors including sample characteristics, volume availability, levels of concentration, and types of measurements to be made will affect the decision when choosing the appropriate path length of a cuvette for your applications.

For a standard spectrometer cuvette, the light path or path length is the distance between the interior walls of a cuvette where the light goes through, which refers to the inner distance between the front window and the back window cells. Cuvettes come in a large variety of pathlength. The most common path length of cuvettes is 10 mm.

When taking sample measurements found at low concentrations — for example, RNA, single-stranded DNA, and oligonucleotides — it’s recommended a long enough path length for the data readings are within the linear measuring range of the instrument.

As we all know, higher concentration solutions must be either diluted or using a cuvette with a shorter path length to simulate the dilution. Known from the Beer-Lambert law, A light path of 1 mm cuvettes will allow dsDNA concentration to be as high as 1,000 µg/mL.

It’s a piece of good news that cuvettes with an optional path length are now available with us, it can roll small volume path length such as 2 mm and a standard 10mm into one.

These 3 ZD values also correspond to the height of the light beam generated by the device. You can click here for more micro and semi-micro cuvette.

It is very crucial to make sure that the cuvette you order is right to the light beam, especially when you’re going to order a sub-micro cell.

For example, if you order a  QM25-15, 10ul sub-micro cuvette, with 15mm z-dimension, when using it to a 8.5mm ZD machine, the light beam will shoot too low and miss the sample chamber giving you 0% light transmission.

The correct Z dimension or Z height or center beam height for your device should be detailed in the literature supplied by the producer with the instrument. And you can also hop on over to the right tables to check the ZD of your spectrophotometer device.
But if you are still not sure, you can call the instrument manufacture up or send us an () to find out the Z dimension of your instruments.

The reason we use the ‘80%’ is because we should never fill up a cuvette over 80%, or it will take an enormous risk to spill because the samples are too close to the top of the cuvette.
But there is an exception! For a sub-micro quartz cell or flow cuvette, and the sample you use is small enough to 10-400uL, then it’s crucial to make sure there is enough sample in the cuvette for the laser light to pass through.

There are some micro cuvettes we offer below. And you can click here for more Semi-Micro(0.35-3.5ml) and Micro(<3.5ml) Volume cuvette.

If you taking our QS37,10 mm cuvette, and your spectrophotometer has a ZD of 8.5mm. You want to make sure that the sample reaches at least 15mm high in the cuvette. So, we will use the same volume formula as above, but change the height to 15 mm and leave out the 80% value.

10 x 10 x (15-1.25) = 1.375 mL

Side note: We subtract 1.25 from the 15 value.

Here are the volume sizes offered by ecuvettes.com, We have dimension charts on each product page that show you exactly what figures you need. 

7. Do you need custom cuvettes?

If the cuvettes listed on ecuvettes.com do not fit into your requirements, then us for customizing any of the hundreds of cuvettes from our product line to produce exactly what you need. 

Here are some customize cuvettes from other clients produced in our cell line, and you can click here for more custom cuvettes.

For more information, please visit Quartz Crucible.

What would you all more experienced folks reccomend for crucibles when trying to keep cost down as much as possible ? Do the cheaper "one shot" type crucibles work well for black sand smelting with a microwave furnace or is there possibility of them getting too hot and breaking down ? I see the graphite ones are rated for higher heat , but they also cost more and , while I do know the safety procedures and am no stranger to working with hazzardous processes , Im trying to put together the materials needed to atleast give this a try , but but as affordable as possible. I appreciate any info you can give. do you mean you're using an actual microwave as a furnace? or induction furnace?
either way, I don't have a good recommendation for you (there are different recommended crucibles for each method of heating)
But if you're going to use a microwave, that's so cool!
I think I've heard of people using the sprue of a mold as the "crucible" in a microwave furnace. the whole mold goes in the microwave, and when you open it, it's only to let it cool and remove the casting. theres a video somewhere in the forum, i cant remember where, that shows the microwave furnace in action. the company that sells the proprietary ingredients as far as the flux goes recommends the use of the furnace for black sand concentrates.the video is cool but as far as i know, none of our members have used one. or if they have, they havent shared it with the forum.

MysticColby said: do you mean you're using an actual microwave as a furnace? or induction furnace?
either way, I don't have a good recommendation for you (there are different recommended crucibles for each method of heating)
But if you're going to use a microwave, that's so cool!
I think I've heard of people using the sprue of a mold as the "crucible" in a microwave furnace. the whole mold goes in the microwave, and when you open it, it's only to let it cool and remove the casting.

A kiln goes into the microwave with the crucible inside. The only kiln Ive found available to buy for this purpose is made of layers of ceramic fiber board , but I am trying to come up with a cheaper do it yourself alternative using either firebrick or clay chimney liner. The microwave energy causes the iron in the black sand to heat up , probably arcing , and will reach a temperature high enough to melt any gold present , then it sinks to the bottom. When its finished you just pour into a mold where the gold sinks below the slag and forms a button. I have communicated online with a couple people who do this regularly and have good results with the commercial model. Smelting the Black Sand is not always very efficient, no matter what method is used to heat the material. Most of the PMs remain dispersed in the black slag that results. One has to get rid of the Iron content before smelting, otherwise it just makes a mess. Not all Black Sands are the same. One has to study the makeup of the particles and devise a process plan for that particular material.

Microwave smelting is just another example of Cargo Cult Science.

https://en.wikipedia.org/wiki/Cargo_cult_science For most microwave smelting applications a fused silica crucible is best due to being microwave transparent and a thermal insulator. This lets microwave energy pass through to the contents and retains the heat produced which is held in the confined space of the kiln assembled in the oven space.

The graphite crucible is best for higher heat applications. Gas fired and induction type smelters are what I would use a graphite crucible with. The thermal conductive properties of graphite make it ideal.

Graphite crucibles should not be used with microwave smelters due to being a poor conductor of microwave energy.

Each in it's place. I remember that post concerning the microwave oven. It was in the build your own equipment forum under the heading of "Terracotta chimney liner for microwave kiln ?" There's even a video posted by Palladium which shows the process. Here's a link to the video: http://www.microwavegoldkiln.com/instructions

Seems to me that would be really hard on a microwave to use it like that. I would recommend buying a "disposable" microwave if you want to try this and not use your kitchen microwave. Either way, if you try it, let us know how it works. It appears you need about 3 times more flux than black sand/gold mixture. It also seems like the batches you can produce would be rather small, especially if you have a couple hundred pounds of black sand to process. Just looked it up on their website and the basic kit was $269.00. If you want a cone mold, the kit is $343.00. The flux is $29.00 for 5 pounds and $75 for 15 pounds. Again, if you go this route, let us know what your results are. It sure would be nice to know what makes up their flux. I'm sure you could make it yourself and cheaper than what they sell it for. This might be a good place to post a similar question...Ive read from a few separate sources that you can use a potato as a crucible...basically cut the potato in half...use a spoon to make it a bowl...use a propane torch to cover the exposed potato with carbon (burn the potato)...then put your material to melt in the center a little at a time...anyone ever tried this?...pros...or cons? Meh1,

Old miners used the potato to remove mercury from amalgam gold (a dangerous process).

It would not work good for melting your gold (too much moisture).

Wood although has moisture even in old dried wood would make a better choice if your melting gold in a cave.

Melting dishes are so cheap and easy to get why take chances with such an expensive metal, just spend a couple of dollars and get a melting dish, spend ten dollars and buy several at once, this way you can melt thousands of dollars of metal with no problems. Evening All, now, i've read through the thread and did not see mention of the composition of the flux used, i apologies otherwise. 8)

Silicone Carbide is a very strong microwave receptor, gets really really hot.

If a flux swells, the chances are it contains compounds such as carbonates, borax, and moisture, well those are the ones most common to me; could even contain calcium fluoride.

Probably has something to do with why they stir the mix during the melt. 8)

Deano Good Morning,

Maybe one of you can help me with the math on something like this. At six dollars a pound for the flux and needing to use three times the flux as black sand your looking for black sand that Assays around 21oz a ton at $ gold to break even? If anyone out there needs help shoveling black sand like that I have a shovel and I'll pick up a spare on the way.
I must be doing this wrong. I have been saving my blacksands for some time and I have a couple hundred pounds that some day I will figure out what to do with. I'll add for clarity that it all came prom panning my cons off a highbenker and sniping.

All the best,
John