Hey there thanks for your clarification! And yes this is definitely a lesson that I'll remember for life - I don't want to be caught in this kind of mistake ever again.
Just to be sure, can you please have a look at what I've submitted?
This is what I've written
1. A stock solution of 100μg/cm³ has been obtained by diluting 0.01g of anhydrous quercetin (in powder form) into 100cm3 of deionized water. 0.01g of anhydrous quercetin has been measured using an Excell BH-600 electronic balance with an uncertainty of ±0.01g, and 100cm3 of deionized water has been measured using a 100cm3 measuring cylinder.
2. 20μg/cm³, 40μg/cm³, 60μg/cm³ and 80μg/cm³ of aqueous quercetin solution have been obtained by diluting from the stock solution of 100μg/cm³1.
3. 1.0 cm³ of 20μg/cm³, 40μg/cm³, 60μg/cm³, 80μg/cm³ and 100μg/cm³ of aqueous quercetin werre added to 14.0cm³ centrifuge tubes containing 4.0 cm³ of water. This amount has been measured using a micropipette of 1000 microlitres.
4. 0.3 cm³ of 5% NaNO2 was measured using a micropipette and added to the above mixture. After 300 seconds, 0.3 cm³ of 10% AlCl3 was added. After 300 more seconds, 2.0 cm³ of 1 M NaOH was added and the total volume was made up to 10cm³ with deionised water.
5. The solution was mixed well using a glass rod and the absorbance was measured against the reagent blank (that is freshly prepared) at 510 nm using a photo-spectrometer.
6. Total flavonoid content of the extracts was expressed as Quercetin equivalents per 100.0g weight of sample in the form of micrograms per unit volume (cm3).
This is what I've just found on the internet.
Total flavonoid content was measured by the aluminium chloride colorimetric assay. An aliquot (1 ml) of extracts or standard solutions of quercetin (20, 40, 60, 80 and 100 μg/ml) was added to a 10 ml volumetric flask containing 4 ml of distilled water. To the flask, 0.30 ml of 5% NaNO2 was added and after 5 min, 0.3 ml of 10% AlCl3 was added. After 5 min, 2 ml of 1M NaOH was added and the volume was made up to 10 ml with distilled water. The solution was mixed and absorbance was measured against the blank at 510 nm. The total flavonoid content was expressed as mg quercetin equivalents (QE). The results for total phenolic and total flavonoid content and the ratio of total flavonoids/total phenolics in the studied plant extracts are presented in Table 1.
As you may have noticed, my 4th point is strikingly similar to the online research report which I forgot to reference. My only saving grace (if any) is in the form of a referenced literature review:
The aluminium chloride colorimetric assay quantifies the amount of flavonoids present in the crude flavonoid extract (CFE). Aluminium chloride combines with the ketone and hydroxyl groups to form acid – stable complexes . The Al3+ cation also forms acid complexes with hydroxyl groups in one of the two flavonoid rings, allowing for spectrophotometric analysis at 510nm .
What do you think? Can I please have your opinion? Even if I get away from this I won't use this as an excuse to repeat this error. Then again, my examiner may have differing views; I would just like to have another person's opinion.