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WINERY & VINEYARD EQUIPMENT January 2018 WINES&VINES 87 10 or 10 packs of 10 tests. A few tests have no additional reagent bottles; the user simply adds the sample to analyze. The shelf life of most tests is about 18 months from manufac- ture (travel time to the winery reduces the shelf life to about 12 months). Since the kits are mostly sold in 10-test packs, wineries should able to use a pack within the fresh timeframe. Most test packs require storage at refrigerator temperature. When performing a test, the LCD screen prompts direct every step. Once each sample is analyzed, a printout pops up with the neces- sary information. If the direct-to-computer cables are installed, data can be saved to a computer file. Most tests use one to three injections of 10 to 100µl. This process is easy to learn (you can practice with water to develop your tech- nique). This is probably the most difficult part of learning the new lab procedures, but neces- sary as the goal is to get consistent results. The cost of the tests ranges from about $3.50 to $6 per test. The common tests are usually in stock, and when not, the delay is usually not long. Advance arrangements should be made for the lesser used test kits. Proprietary software for computer display of results can be downloaded during setup. Megazyme MegaQuant Wave Simplified enzymatic testing using a defined wavelength spectrophotometer The MegaQuant Wave, introduced by Mega- zyme, was one of the first spectrophotometers to offer a simplified way to perform enzymatic testing. Their instrument uses a tungsten lamp light source and comes equipped with six in- terference filters providing wavelengths of 340, 405, 505, 545, 580 and 630 nm as stan- dard. The linear range is 0 to 3 absorbance units that easily accommodate the range of most enzymatic tests. The MegaQuant Wave accommodates 12 sample tubes in the incuba- tion block. This block only accepts round 12 mm diameter tubes. However, the actual mea- suring cell accepts both 10 mm cuvettes as well as the 1 mm x 10 mm cuvettes in addition to the round tubes. The accuracy of a reading is 0.005A, or about 1% of the reading. On startup, the onboard touchscreen pres- ents tabs including utilities, settings, tests and manage tests, and the user enters specific in- formation to customize the printer output. Most of the time the screen input centers on the list of tests, and you select the one to run. The MegaQuant Wave has a repertoire of 24 separate test kits for the wine industry. The average test kit has three to five reagents that are added to the test tube or cuvette using micro-pipettes. The instrument provides step- by-step instructions for processes such as nec- essary dilutions, sample insertions, and when to insert or remove a tube. On completion of the test, the instrument calculates and prints out the results or sends those results to exter- nal software, such as the SF Capture software available from Megazyme. Megazyme test kits come in different con- figurations of reagents. The stability of their reagents is generally two years. This is impor- tant since the number of tests in any one kit ranges from 50 to 100 tests. The cost per test is $3 to $5 per full test. However, if the user runs the half-volume test, the lab can get twice the number of tests out of one test kit, reducing all reagent costs by half. The MegaQuant Wave test kits often require both refrigerated and freezer storage to get the two-year shelf life out of the kit. If you use the tests in six to 12 months, freezer storage may not be required. The MegaQuant Wave protocol for analysis and the reagents used gives the instrument greater sensitivity at low concentrations. Hanna Mini Titrator Titratable Acidity Step motor precision increases ease of use and accuracy The Hanna Mini Titrator automates what the wet chemistry burettes have done for decades. The principle of operation is the same, but modified to specific standards, so more repeat- able and accurate results can be obtained. The instrument is driven by a step motor. It drives a plastic syringe that is attached to a base platform and, in precise steps, raises the plat- form, pumping a titrant into a reaction beaker. A pH probe measures the amount of standard- ized base that is added to the wine sample until the endpoint is determined. The probe output is sent to the stored algorithm in the meter and is then converted into a digital display. A USB port can connect to a thumb drive or, via a cable, to a PC. The exported log files allow further investigation of the analyzed data. In the setup menu, the user selects the endpoint (pH 7.0 or 8.2) as well as tempera- ture unit choices (C, K or F), date, time, the number of days until a notice for recalibration and a choice of resolution (0.0 or 0.00) that the meter shows when returning the results. Calibration of the pH probe and the pump is done after setup. This task is necessary when any component changes, such as the titrant, syringe or probe. One quirk of the meter in calibration mode is the short time between the endpoint calibration and at least one other calibration point. The LCD screen makes it appear as if the wrong buffer was chosen. Simply putting the next buffer in allows the meter to recognize the new buffer and cali- brate to that one. The pump is calibrated by adding a calibration standard to the analysis beaker and setting the meter first at high range (4 to 25g/L) and then calibrating again at low range (0.1 to 5 g/L). The meter can log a total of 400 results, 200 pH/mV and 200 titration results. The cost for a complete system is $825, and the meter can double as a pH meter. Hanna Mini Titrator SO 2 Step motor precision dials in your results on levels of SO 2 The SO 2 mini titrator is similar in design to the titratable acidity meter above. The differences are specific to the analysis (free or total sulfur) run with the instrument. The same step motor function controls the syringe delivery of the titrant, and there are similar functions to setup date, time, etc. Once a worker masters one meter, the differences are in the reagents and their amounts that are specific to the meter. The only real difference between the two meters is a function in the SO 2 meter that damps noise in some titrations. In my experi- ence, it generally is not necessary for most ti- trations, and this function can be turned off. The basic theory is to dampen the signal by taking a percent of the first derivative of the signal. Fortunately, this number is calculated during calibration. The SO 2 mini titrator also allows the user to adjust their threshold which allows them to adapt the method to better analyze their wine. Hanna Edge pH, EC and DO Meter Slim design and multiple probes increase lab functionality The Edge meter combines the ability to have three different probes used with one base meter. It is similar to a tablet device and has two different mounting platforms: a benchtop meter or a wall-mounted device. It is powered by a USB cable connected to a wall outlet; when fully charged, it can operate off an in- ternal battery for several hours. This meter can accept pH, electrical conductivity (EC) and dissolved oxygen (DO) probes, but only the pH and EC probes are examined in this study. According to a Hanna representative, many wineries needed oxygen levels to be measured below 0.01 ppm ± 1.5%, and that is the lowest amount that this probe can ac- KEY POINTS This article about analytical laboratory equipment reviews how each instrument operates, how specific analyses may differ between instruments and options for cre- ating a wine lab. Included are details on the specifications and capabilities of equipment from CDR WineLab, Hanna Instruments, Megazyme and others. The difference between precision and ac- curacy of analyses is discussed, along with tolerance and how to weigh these fac- tors against the speed of testing and cost of equipment.