Chromic Sulphate (Cr2(SO4)3.6H2O is ment to be soluble in water, however the product (UniChem) we have is not at all. How can that be?

We want to use Chromic Sulphate (Cr2(SO4)3.6H2O) to contaminate soil, however we found it not to be soluble in water while according the literature and tanning practices this should be soluble in...

31 December 2018 6,104 3 View

Analysing digested filtrate using the UV spectro-photometer and DPC is difficult due to strong discolouration of the filtrate. How can we avoid that?

We've been digesting soil samples with heated NaCO3 and NaOH mixtures. The brown discolouration of the filtrate makes it difficult to use DPC under acid conditions to detect Cr6+. Yet people use...

11 December 2018 564 1 View

A large range of Cr content on the same soil sample was measured with the AAS. Why could this be?

We've been digesting the same soil in a number of different ways and measuring the Cr content of the filtrate using an AAS. The results are highly variable, and only remotely reflected the levels...

11 December 2018 5,641 9 View

How to quickly acidify a loamy soil?

I'm working with some loamy soil with a pH(1:5) of about 8. I would like get it down to pH of 6 AND grow some crops on the acidified soil. What would be the quickest and reliable way of achieving...

31 December 2017 733 1 View

Why is the light spectrum distribution of white (6000K) LED tubes similar to warm (3000K) LED tubes?

01 January 1970 9,939 8 View

Does the pressure(-600 mmHg) affects pH?

When I conducted the degassing experiment using decompression under anaerobic condition(and I used ferrous based chelating agent), the oxidized ferric were observerd. So, could you tell me the...

03 March 2021 4,892 5 View

Is There Any Feasible Method To Test Fluorescent Compounds Other Than Fluorescence Spectrometers ??

Is There Any Feasible Method To Test The Efficiency Of Fluorescent Compounds Other Than UV Spectrometers ? Suggestions Would Be Appreciated !

02 March 2021 5,785 3 View

Which database would give me this list of chemical components?

Dear colleagues: I would like to know if anyone knows of a database that gives me the parameters pH, K, K, Mg, P, C, N, Zn, Cu, Ni and Cd of common foods. I find a lot of information of proteins,...

26 February 2021 5,525 3 View

Standard curve shifting over time. How do I stabilise the ELISA?

24 February 2021 1,365 3 View

Why is NH4OH added in heavy metals limit test?

The limit test I'm referring to is USP method II. In this procedure you need to dropwise add 6N of NH4OH to the sample until it the pH is alkali. After that you need to dilute and add HOAc until...

23 February 2021 2,049 3 View

How does the injection volume impact LLOQ and ULOQ in regression analysis (LC-MSMS)?

Hello, I have run into an issue that has sparkled a debate at work: is the LLOQ/ULOQ impacted by injection volume under the following circumstances: 1) Same dilution factor of all samples 2)...

23 February 2021 9,159 3 View

Is there an ideal incubation time of RGO-modified SPCE before subsequent use, i.e., electrochemical characterization or further modification?

I notice that upon washing and air-drying of my RGO/SPCE surface and characterizing again via DPV, the current response towards ferricyanide probe significantly decreases. My worry is that the...

22 February 2021 5,324 3 View

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22 February 2021 9,932 11 View

Can anyone help or comment on solubilising chlorobutanol in aqueous injections in minimum time possible?

Please suggest solubilisation of chlorobutanol in injections. Tried pH and high temperature. But the issue is of assay drop. If anyone can suggest any solution. Its a commonly used excipient for...

21 February 2021 7,397 1 View

What reaction will occur when adding hexamine into ammonium nitrate in an acidic medium?

Hello, I am investigating properties of water in oil emulsion explosives. And adding hexamine (hexamethylenetetramine) into one of the phases that are used to make the emulsion should increase the...

21 February 2021 8,680 1 View