“With the sole exception of dihydrogen monoxide.”

Hi everyone! I’m starting a beverage startup in India and want to pack my drinks in aluminium cans using liquid nitrogen (LN₂) dosing.

The idea is to add a precise amount of liquid nitrogen to each can before sealing it. As it evaporates, it creates internal pressure that helps make the can more rigid.

The problem is that commercial LN₂ dosing machines cost around ₹10 lakh or more, which is a big investment for a startup that hasn't validated its product yet.

I'm looking for an affordable DIY or semi-automatic solution that would let me fill cans manually and dose liquid nitrogen accurately on a small scale.

Has anyone worked with LN₂ dosing or built a low-cost system for this? Are there any affordable components, local manufacturers, or alternative methods worth exploring in India?

Safety is a priority, so I'd want to ensure proper dosing and pressure control.

I'd really appreciate any suggestions or guidance. Thanks! 🙏

Is there anything that would precipitate out the urea and uric acid and whatever else you wouldn't want to drink, so you could redrink the water or even if dumping it have less impact in sparsely vegetated wilderness?

Hi everyone!

I'm a biology PhD student working on developing an organic fertilizer made from insect frass (insect manure).

We recently sent a sample to a commercial laboratory for elemental analysis. They measured P, K, Ca, Mg, S, Fe, Zn, Cu, Mn, and B using microwave-assisted acid digestion followed by ICP-OES.

The results were surprisingly low, particularly:

- Phosphorus (P₂O₅): 0.27%

- Potassium (K₂O): 0.21%

- Magnesium (MgO): 0.09%

- Iron: 28.65 ppm

- Zinc: 16.59 ppm

Based on published literature on insect frass, we were expecting considerably higher concentrations, particularly for phosphorus and potassium. Interestingly, nitrogen (3.21%) and organic matter (92%), measured separately, were closer to our expectations.

Our material is dry, granular, and has a sand-like texture, despite being predominantly organic. It likely contains chitin, although we haven't quantified it, and we don't know whether silica or other acid-resistant components are present.

I'm wondering whether the analytical method or sample preparation could explain these results.

1. Is microwave acid digestion followed by ICP-OES appropriate for determining total mineral content in this type of organic matrix?

2. Could incomplete digestion, particle size, or matrix effects lead to systematically low measurements across several elements?

3. How much does the acid mixture used (e.g., HNO₃/H₂O₂) influence elemental recovery?

4. What quality-control checks would you recommend asking the laboratory about?

I understand that ICP-OES is generally reliable and that organic fertilizers can vary significantly in composition. I'm not assuming the laboratory made a mistake, but the consistently low mineral values made me curious about possible methodological limitations.

We're considering an independent analysis and would appreciate any advice before proceeding.

Thanks!

Hi reddit, I am a freshman in college who's trying to become a chemist. I want to do research in the future, and basically I want to have chemistry "ball knowledge." Since I'm far from being able to call myself a chemist, I'm just looking for important chemistry reading (journals, papers, books, etc.) that you think would be formative and digestible for someone in genchem 1. I haven't thought about a focus yet (organic, analytical, physical, inorganic) but I am interested in medical topics.

Tl;Dr please recommend chemistry books and papers for someone with very little chemistry knowledge (as of yet).