question: How does the concentration process work?
comment: Juice is 99% water, 1% dissolved solids. You can just evaporate off the water until you're risking the solids coming out of solution. Sometimes you can keep going and create a dry powder of juice/milk solids, sometimes you can't if there are other liquids present or the solids aren't stable in air. This is pretty standard practice for anything that gets shipped. Most juices are concentrated as much as possible near their original farms and mixed/rehydrated later. Nobody's paying to ship millions of gallons of 99% water across the Pacific when it's practically free on the other end.
passages: Section::::Components.:Distribution.
  
  The compound needs to be carried to its effector site, most often via the bloodstream. From there, the compound may distribute into muscle and organs, usually to differing extents. After entry into the systemic circulation, either by intravascular injection or by absorption from any of the various extracellular sites, the drug is subjected to numerous distribution processes that tend to lower its plasma concentration.
   BULLET::::5. Change the dialysis buffer and dialyze for another 2 hours
  
  BULLET::::6. Change the dialysis buffer and dialyze for 2 hours or overnight
  
  The total volume of sample and dialysate determine the final equilibrium concentration of the small molecules on both sides of the membrane. By using the appropriate volume of dialysate and multiple exchanges of the buffer, the concentration of small contaminants within the sample can be decreased to acceptable or negligible levels. 
   Section::::Process details.
  
  During the operations, the ethanol concentration change from zero initially to 40%. The pH decreases from neutral at 7 to more acidic at 4.8 over the course of the fractionation. The temperature starts at room temperature and decreases to −5 degrees Celsius. Initially, the blood is frozen. There are five major fractions. Each fraction ends with a specific precipitate. These precipitates are the separate fractions.
   Variable pathlength absorption spectroscopy uses a determined slope to calculate concentration. As stated above this is a product of the molar absorbtivity and the concentration. Since the actual absorbance value is taken at many data points at equal intervals, background subtraction is generally unnecessary. The image on the right is a linear plot showing both the background corrected data and the raw data.
   Concentrations are often called levels, reflecting the mental schema of levels on the vertical axis of a graph, which can be high or low (for example, "high serum levels of bilirubin" are concentrations of bilirubin in the blood serum that are greater than normal).
  
  Section::::Quantitative notation.
  
  There are four quantities that describe concentration:
  
  Section::::Quantitative notation.:Mass concentration.
  
  The mass concentration formula_1 is defined as the mass of a constituent formula_2 divided by the volume of the mixture formula_3:
  
  The SI unit is kg/m (equal to g/L).
  
  Section::::Quantitative notation.:Molar concentration.
   Section::::Biotransformation.:Distribution.
  
  The distribution of the compound can be observed and analyzed at every dosage in a variety of tissues. The areas that display the highest level of activity can be found in the liver and the whole blood as this is where the major metabolic process takes place. The lowest level of activity for the compound can be observed in the bone and fat of the individual.
  
  Section::::Biotransformation.:Excretion.
   This is commonly used on the small scale in chemical labs. It is normal to use a separating funnel. Processes include DLLME and direct organic extraction.
  
  After equilibration, the extract phase containing the desired solute is separated out for further processing.
  
  Section::::Techniques.:Batchwise single stage extractions.:Dispersive liquid–liquid microextraction (DLLME).
   Rather than being administered by a physician or individual, infectious dosages are transmitted to a person from other persons or the environment, are generally accidental, and result in adverse side effects until the pathogen is defeated by the individual's immune system or flushed out of the individual's system by excretory processes.
   where Q is the drug's purity.
  
  where formula_8 is the drug's rate of administration and formula_9 is the rate at which the absorbed drug reaches the circulatory system.
  
  Finally, using the Henderson-Hasselbalch equation, and knowing the drug's formula_10 (pH at which there is an equilibrium between its ionized and non ionized molecules), it is possible to calculate the non ionized concentration of the drug and therefore the concentration that will be subject to absorption:
   Section::::Secondary active transport.:Symporter.
  
  A symporter uses the downhill movement of one solute species from high to low concentration to move another molecule uphill from low concentration to high concentration (against its concentration gradient). Both molecules are transported in the same direction.
   Section::::Principle of operation.:Rapid evaporative ionization mass spectrometry.
   BULLET::::- C is the concentration [mmol/L] or [mol/m³] (in the United States often [mg/mL])
  
  From the above definitions it follows that formula_3 is the first derivative of concentration with respect to time, i.e. the change in concentration with time.
  
  It is derived from a mass balance.
  
  Clearance of a substance is sometimes expressed as the inverse of the time constant that describes its removal rate from the body divided by its volume of distribution (or total body water).
   Figure 2 shows a Davenport diagram as commonly depicted in textbooks and the literature. To understand how the diagram is to be interpreted, it is helpful to understand how the diagram is derived in the first place. Consider the following experiment. A small sample of blood is taken from a healthy patient and placed in a chamber in which the partial pressure of carbon dioxide (P) is held at 40 mmHg. Once equilibrium is reached, the pH and bicarbonate concentration are measured and plotted on a chart as in Fig. 3.
   Section::::The DGT equation.
  
  DGT is based on the application of Fick's law. Once the mass of an analyte has been determined, the time-averaged concentration of the analyte in the bulk, formula_1, can be determined by application of the following equation:
   Section::::Sample loading techniques.:Liquid injection.
   Methiocarb can be taken up through different routes. The most common for humans is up take through the skin or as an aerosol, because of its use as a pesticide in agriculture. For insects and birds this would be by the oral route. The NOAEL’s of these routes have been determined as follows: For the oral route, the NOAEL is set to 3.3 mg/kg per day for rats, based on a 2-year study. For absorption through the skin the NOAEL is set to 150 mg/kg per day for rabbits, based on the reduction of food consumption.
   The rate of dissolution is described by the Noyes–Whitney equation as shown below:
  
  Where:
  
  BULLET::::- formula_2 is the rate of dissolution.
  
  BULLET::::- A is the surface area of the solid.
  
  BULLET::::- C is the concentration of the solid in the bulk dissolution medium.
  
  BULLET::::- formula_3 is the concentration of the solid in the diffusion layer surrounding the solid.
  
  BULLET::::- D is the diffusion coefficient.
  
  BULLET::::- L is the diffusion layer thickness.
   For example, when dialyzing 1mL of sample against 200mL of dialysate, the concentration of unwanted dialyzable substances will be decreased 200-fold when equilibrium is attained. Following two additional buffer changes of 200mL each, the contaminant level in the sample will be reduced by a factor of 8 x 10 (200 x 200 x 200).
  
  Section::::Dialysis Procedure.:Variables and Protocol Optimization.
  
  Although dialyzing a sample is relatively simple, a universal dialysis procedure for all applications cannot be provided due to the following variables:
  
  BULLET::::- The sample volume
  
  BULLET::::- The size of the molecules being separated
  
  BULLET::::- The membrane used
   Transport maximum
  
  In physiology, transport maximum (alternatively Tm or T) refers to the point at which increases in concentration of a substance do not result in an increase in movement of a substance across a cell membrane.
  
  In renal physiology, the concept of transport maximum is often discussed in the context of glucose and PAH.
  
  For both substances (as with all substances), the quantity "excreted" can be determined with the following equation:
  
  BULLET::::- "excretion" = ("filtration" + "secretion") - "reabsorption"
   Gravity-flow, or drip, columns use head-pressure from a buffer-chase to push the sample through the gel filtration matrix. Sample is loaded into the top of an upright column and allowed to flow into the resin bed. The sample is then chased through the column by adding additional buffer or water to the top of the column. During this process, small fractions are typically collected and each is tested for the macromolecules of interest. In some cases, several fractions might contain the protein and may have to be pooled to improve yield. In order to eliminate the time and monitoring assorted with drip columns, fractions often equal to the full exclusion volume of the column are collected regardless of sample volume resulting in significant dilution of sample.
   As can be inferred by the Noyes-Whitney equation, the rate of dissolution may be modified primarily by altering the surface area of the solid. The surface area may be adjusted by altering the particle size (e.g. micronization). For many drugs, reducing the particle size leads to a reduction in the dose that is required to achieve the same therapeutic effect. The reduction of particle size increases the specific surface area and the dissolution rate, and it does not affect solubility. 
   The low-flow-rate method is based on the fact that the extraction efficiency is dependent on the flow-rate. At high flow-rates, the amount of drug diffusing from the sampling site into the dialysate per unit time is smaller (low extraction efficiency) than at lower flow-rates (high extraction efficiency). At a flow-rate of zero, a total equilibrium between these two sites is established (C = C). This concept is applied for the (low-)flow-rate method, where the probe is perfused with blank perfusate at different flow-rates. Concentration at the sampling site can be determined by plotting the extraction ratios against the corresponding flow-rates and extrapolating to zero-flow. The low-flow-rate method is limited by the fact that calibration times may be rather long before a sufficient sample volume has been collected.
   Due to the pore size of the membrane, large molecules in the sample cannot pass through the membrane, thereby restricting their diffusion from the sample chamber. By contrast, small molecules will freely diffuse across the membrane and obtain equilibrium across the entire solution volume, thereby changing the overall concentration of these molecules in the sample and dialysate (see dialysis figure at right). Once equilibrium is reached, the final concentration of molecules is dependent on the volumes of the solutions involved, and if the equilibrated dialysate is replaced (or exchanged) with fresh dialysate (see procedure below), diffusion will further reduce the concentration of the small molecules in the sample.
   Concentration
  
  In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration. A concentration can be any kind of chemical mixture, but most frequently solutes and solvents in solutions. The molar (amount) concentration has variants such as normal concentration and osmotic concentration.
  
  Section::::Qualitative description.
   Section::::Modes of operation.:Ion-exchange and pH-Zone-refining.
  