Laboratory Procedures for Using OCTAPOL® in Cane Sugar Factory Process Streams (revised 09/19/2017)
1. INTRODUCTION:
Octapol® is shipped in an unactivated state. It is stable indefinitely in this state, provided that it is not exposed to moisture.
A few minutes before a bottle of Octapol® is to be used for the first time, it must be activated. This is done simply by removing the plastic bag containing the “ACTIVATOR” and emptying the contents of the bag into the bottle. Then the capped bottle should be shaken manually and VIGOROUSLY for at least FIVE MINUTES to insure good mixing and homogeneity of the components. It is now ready for use. However, because the powder is very finely divided and dusty, it should be allowed to sit for a few minutes before the bottle is opened.
IMPORTANT: THE QUANTITY OF REAGENT USED SHOULD BE THAT AMOUNT (DETERMINED BY EXPERIMENTATION) WHICH GIVES THE BEST BALANCE OF CLARITY AND FILTRATION RATE FOR THE PARTICULAR KIND OF SAMPLE BEING ANALYZED.
Generally, weights between 5 and 10 grams should work well for most samples in the 100 to 200 ml range.
Aids to filtering (Filter Aid, Diatomaceous Earth, Kieselguhr, etc) are not required with Octapol®.
2. SOME GENERAL GUIDELINES
As with dry Lead Subacetate and other clarifying reagents, the amount of Octapol® required may vary depending on the nature of the sample. Depending on the appearance of the filtrate after treatment with the clarifier, the following general statements may be made.
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IF THE FILTRATE IS CLEAR AND SLIGHTLY YELLOW: This is perfect!
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IF THE FILTRATE IS CLEAR AND DARK: Increase the amount of clarifier.
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IF THE FILTRATE IS CLOUDY AND DARK: Increase the amount of clarifier and let sample stand longer after shaking before it is filtered. Also, double filtration may be helpful.
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IF THE FILTRATE IS CLOUDY AND SLIGHTLY YELLOW: Let the sample stand longer after shaking before it is filtered. Fluted filter paper and/or double filtration may be helpful.
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IF THE FILTRATE IS CLEAR AND COLORLESS: Try decreasing the amount of clarifier.
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IF THE FILTRATE IS CLOUDY AND COLORLESS: Decrease the amount of clarifier.
3. SPECIFIC PROCEDURES:
Although the reagent is non-toxic and environmentally benign, it is a very fine powder and a nuisance dust. The usual precautions involved in handling such dusty materials should be taken. Do not breathe the dust. Wash hands, forearms, and other exposed areas thoroughly after handling. Do not eat, drink, or smoke when handling this product. Wear a dust mask, protective gloves, protective clothing, and eye protection. Get medical attention if you feel unwell. Dispose of wastes in accordance with local, regional, national, and international regulations. A Safety Data Sheet is available on request.
Note that there is only a very small (negligible in practice) effect of the quantity of the Octapol® used upon the polarimeter readings obtained, and this is very much lower than the effect of the quantity of Lead Subacetate on the polarimetric readings. With Lead Subacetate, the polarimetric readings vary with the quantity of Lead Subacetate added to the juice sample.
All polarization readings should be done using the 200 mm tube since the reagent should produce clarified filtrate of enough color and turbidity for this.
The purity data, etc. calculated from the polarimeter readings obtained with the use of Octapol® should be done in the same way as those obtained using Lead clarification.
Although weights of reagent are given in the procedures described below, they are only meant as a guide and the analyst should experiment and judge the quantity to be used, especially in the Core Lab, by eye after weighing a few samples and gaining experience with Octapol®. AGAIN, the quantity of reagent used should be that which gives the best filtration rate and clarity.
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CORE LAB JUICES, MILL JUICES, CLARIFIED JUICE, AND FILTRATE
Pour 100 ml of juice into a 200 ml bottle fitted with a stopper. Add about 5-6 g of the reagent to the sample, stopper tightly, and shake VIGOROUSLY for about 20 seconds. Failure to shake and mix sufficiently may result in sub-standard clarification of samples. After mixing, the appearance of the mixture at this point may be described as like a “milk shake”.Pour the mixture into filter paper (FLUTED FILTER PAPER will gives faster filtration than ordinary filter paper). Discard or pour back the first 10 ml of filtrate if necessary. (With respect to mixing, an alternative procedure to that described above would be to use a beaker to contain the juice sample/reagent mixture, then mix with an inexpensive mechanical mixer, such as used to scramble eggs, for example). This is more effective than manually shaking a stoppered bottle as is commonly done in many Core Labs.
Note that a blinking polariscope with instability may be remedied by the use of 2 pieces of filter in the funnel simultaneously for the sample. This sometimes will ensure proper clarity of the samples, and allows the readings to be stable . If the 2 pieces of filter paper are not employed, even though the sample appear to be clear,the polariscope will sometimes blink on readings and be very slow to stabilize, if at all. The double filtration usage usually solves this problem.
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Bagasse and Filter Cake Analysis
Prepare the bagasse extract extract in the conventional manner using a blender. Cool the solution, pour about 100 ml into a 200 ml bottle with a stopper. Add a few grams of clarifier, shake well and filter. -
Syrup Analysis
Weigh 26 g of syrup into a 200 ml flask, add water to the mark and mix well. Pour about 100 ml into a 200 ml bottle with a stopper. Add about 5 g of reagent, shake well and filter. -
Masscuite and Molasses Analysis
Prepare a 1:1 dilution of the material in the usual way. Weigh 26 g of the diluted material into a 200 ml flask, add water to the mark, and mix well. Pour about 100 ml into a 200 ml bottle with a stopper. Add reagent, shake well and filter.
The quantity of reagent required depends on the purity of the material being tested. Recommended quantities are:
A-Massecuite, 5-6 g
A-Molasses and B-Massecuite, 6-8 g
B-Molasses and C-Massecuite, 8-10 g
Final Molasses, 10-15 g -
Raw Sugar Analysis
Octapol® can be used to determine the polarization of raw sugar. Only a small amount of reagent is necessary and it is important to avoid excess reagent in order to achieve clear filtration. The recommended procedure is as follows: Weigh 26.00 g of raw sugar and dissolve in water to a final volume of 100 ml in the usual way, making sure that all the sugar has dissolved and that the solution is well mixed. Pour the solution into a small, clean, and dry beaker, add about 1.5 g of clarifier and stir with a glass rod or spatula. Cover with a watch glass and allow to stand for a few minutes. Filter and determine polarization in the usual way.
4. ADDITIONAL COMMENTS
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Experimental data on a large number of sugar samples show that the pol value by this procedure may average slightly lower that with Lead reagents, but the same as for the ABC Sugar Clarifier.
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THIS PROCEDURE IS NOT THE PROCEDURE INCLUDED IN RAW SUGAR CONTRACTS.
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In contrast to Lead Reagents, Octapol® does not precipitate much, if any, dextran. Some high dextran raw sugars may show slightly higher polarization with Octapol® than with Lead reagents since dissolved dextran adds to the pol.
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Pol values for lower purity materials such as Final Molasses show larger differences for the pol values when Octapol® and Lead Subacetate data are compared. Results from SMRI in Durban, South Africa show that both pol procedures give good estimates of the optically active substances in solution after clarification. The large discrepancy between the Octapol® percent and the Lead Subacetate percent is attributed to the fact that Lead Subacetate precipitates some of the Fructose present in the sample whereas Octapol® does not. Since the rotation of a sample is additive for all the optically active components present, Octapol® filtrates with their higher Fructose concentrations (which being levorotatory subtracts from the measured polarization) will have lower overall optical rotations and hence lower pol readings.
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Pol results for both Dextran and Fructose-containing samples substantiate the idea that Octapol®, unlike Lead Subacetate, does not change the chemical composition of the sugar stream sample. Thus, the Octapol® pols are less artificial than the Lead Subacetate pols.
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