jfox,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.yellow {
background-color: #FFFF00;
}
.info {
color: #FF0000;
}
</style>
</head>
<body>
<table>
<tbody>
<tr>
<th class="min-width"><input type="checkbox" class="s-select-all" data-count="6116"></th>
<th>Код артикула</th>
<th>Название</th>
<th>Цена</th>
<th>В наличии</th>
</tr>
<tr class="product ui-droppable ui-draggable" data-product-id="6636">
<td class="min-width drag-handle"><input type="checkbox"></td>
<td class="s-product-col-sku" title="Код артикула">21400</td>
<td class="drag-handle s-product-name">Велосипед</td>
<td title="Цена">50000</td>
<td title="В наличии">5</td>
</tr>
<tr class="product ui-droppable ui-draggable" data-product-id="6637">
<td class="min-width drag-handle"><input type="checkbox"></td>
<td class="s-product-col-sku" title="Код артикула">21401</td>
<td class="drag-handle s-product-name">Велосипед</td>
<td title="Цена">12000</td>
<td title="В наличии">5</td>
</tr>
<tr class="product ui-droppable ui-draggable" data-product-id="6638">
<td class="min-width drag-handle"><input type="checkbox"></td>
<td class="s-product-col-sku" title="Код артикула">21402</td>
<td class="drag-handle s-product-name">Велосипед</td>
<td title="Цена">60000</td>
<td title="В наличии">5</td>
</tr>
<tr class="product ui-droppable ui-draggable" data-product-id="6639">
<td class="min-width drag-handle"><input type="checkbox"></td>
<td class="s-product-col-sku" title="Код артикула">21403</td>
<td class="drag-handle s-product-name">Велосипед</td>
<td title="Цена">13300</td>
<td title="В наличии">5</td>
</tr>
<tr class="product ui-droppable ui-draggable" data-product-id="6640">
<td class="min-width drag-handle"><input type="checkbox"></td>
<td class="s-product-col-sku" title="Код артикула">21404</td>
<td class="drag-handle s-product-name">Велосипед</td>
<td title="Цена">33200</td>
<td title="В наличии">5</td>
</tr>
</tbody>
</table>
<p class="info"></p>
<script>
var a = ["21401","21403","21404", "20400", "20452"], b = [], err;
[].forEach.call(document.querySelectorAll('.product'), function(tr) {
var td = tr.querySelector('.s-product-col-sku');
var kod = td.textContent.trim();
var checked = ~a.indexOf(kod);
checked && b.push(kod);
tr.querySelector('input').checked = checked;
td.classList[checked ? 'add' : 'remove']("yellow")
});
err = a.filter(function(e) {
return b.indexOf(e) == -1
})
document.querySelector('p.info').innerHTML = err
</script>
</body>
</html>